WO2015095725A1 - Methods and compositions for attenuating muscle protein degradation and preserving lean body mass - Google Patents

Abstract

Methods and nutritional compositions are disclosed for attenuating muscle protein degradation, preserving lean body mass, or both in a subject in need thereof. Generally, the nutritional composition includes a source of fat, a source of protein, a source of carbohydrate, a source of β-hydroxy-β-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral. The nutritional composition also generally has from 10 grams to 25 grams of protein and from 240 kcal to 500 kcal per serving.

Description

METHODS AND COMPOSITIONS FOR ATTENUATING MUSCLE PROTEIN DEGRADATION AND PRESERVING LEAN BODY MASS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and any benefit of U.S. Provisional Application No. 61/918,497, filed December 19, 2013, the content of which is incorporated herein by reference in its entirety.

FIELD

[0002] The general inventive concepts relate to nutritional compositions and methods of using nutritional compositions. More particularly, the general inventive concepts relate to methods and nutritional compositions for attenuating muscle protein degradation, preserving lean body mass, or both in a subject in need thereof.

BACKGROUND

[0003] Loss of lean body mass occurs with aging, muscle disuse, surgery, and a number of catabolic conditions including, but not limited to, cancer, burn injuries, chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease. Such loss of lean body mass leads to functional decline, loss of independence, and increased disease burden. The loss of lean body mass is commonly attributed to an imbalance in overall muscle protein processes, with the rate of muscle protein degradation outpacing the rate of muscle protein synthesis.

SUMMARY

[0004] The general inventive concepts relate to methods and nutritional compositions for attenuating muscle protein degradation, preserving lean body mass, or both in a subject in need thereof. By way of example to illustrate various aspects of the general inventive concepts, several exemplary embodiments of methods and nutritional compositions are provided herein.

[0005] In one exemplary embodiment, the invention provides a nutritional composition for use in attenuating muscle protein degradation in a subject in need thereof. This embodiment also provides a method of attenuating muscle protein degradation in a subject in need thereof. The method includes administering an effective amount of a nutritional composition to the subject in need thereof. The nutritional composition comprises: a source of fat; a source of protein; a source of carbohydrates; a source of P-hydroxy-P-methylbutyrate; at least one polyunsaturated fatty acid; at least one monounsaturated fatty acid; at least one vitamin; and at least one mineral. The nutritional composition further has from 10-25 grams of protein and from 240-500 kcal per serving. Administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby attenuating muscle protein degradation in the subject. In addition, this embodiment provides use of a composition comprising a source of fat, a source of protein, a source of carbohydrates, a source of P-hydroxy-P-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral for the manufacture of a medicament for use in attenuating muscle protein degradation in a subject.

[0006] In one exemplary embodiment, administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation within 3 hours of administration.

[0007] In one exemplary embodiment, the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof.

[0008] In one exemplary embodiment, the subject in need thereof is an elderly human. In one exemplary embodiment, the subject in need thereof has an elevated level of at least one intramuscular signaling protein associated with muscle protein degradation. In one exemplary embodiment, the subject in need thereof has an elevated level of 14-kDa actin fragment. In one exemplary embodiment, the subject in need thereof has an elevated level of ubiquitin. In one exemplary embodiment, the subject in need thereof has an elevated level of MuRF-1.

[0009] In one exemplary embodiment, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, and the level of 14-kDa actin fragment is decreased. [0010] In one exemplary embodiment, the nutritional composition is administered in multiple feedings.

[0011] In one exemplary embodiment, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is ubiquitin, and the level of ubiquitin is decreased. In one exemplary embodiment, the nutritional composition is administered in multiple feedings, the at least one intramuscular signaling protein associated with muscle protein degradation is ubiquitin, and the level of ubiquitin is decreased.

[0012] In one exemplary embodiment, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is MuRF-1, and the level of MuRF-1 is decreased. In one exemplary embodiment, the nutritional composition is administered in multiple feedings, the at least one intramuscular signaling protein associated with muscle protein degradation is MuRF-1, and the level of MuRF- 1 is decreased.

[0013] In one exemplary embodiment, the at least one polyunsaturated fatty acid is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof. In one exemplary embodiment, the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid, eicosapentaenoic acid, a-linolenic acid, and combinations thereof, and the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid, arachidonic acid, and combinations thereof.

[0014] In one exemplary embodiment, the at least one monounsaturated fatty acid is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof.

[0015] In one exemplary embodiment, the source of P-hydroxy-P-methylbutyrate is calcium β- hydroxy-P-methylbutyrate monohydrate, and the nutritional composition contains 1-3 grams of P-hydroxy-P-methylbutyrate per serving.

[0016] In one exemplary embodiment, the nutritional composition further comprises a source of fructooligosaccharides. In one exemplary embodiment, the nutritional composition contains 2-4 grams of fructooligosaccharides per serving. [0017] In one exemplary embodiment, the nutritional composition is a liquid and a serving thereof ranges from 115-300 mL. In one exemplary embodiment, the nutritional composition is a reconstitutable powder.

[0018] In one exemplary embodiment, the invention provides a nutritional composition for use in treating the loss of lean body mass in a subject in need thereof. This embodiment also provides a method of preserving lean body mass in a subject in need thereof. The method includes administering an effective amount of a nutritional composition to the subject in need thereof. The nutritional composition comprises: a source of fat; a source of protein; a source of carbohydrates; a source of P-hydroxy-P-methylbutyrate; at least one polyunsaturated fatty acid; at least one monounsaturated fatty acid; at least one vitamin; and at least one mineral. The nutritional composition further has from 10-25 grams of protein and from 240-500 kcal per serving. Administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby preserving lean body mass in the subject in need thereof. In addition, this embodiment provides use of a composition comprising a source of fat, a source of protein, a source of carbohydrates, a source of P-hydroxy-P-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral for the manufacture of a medicament for use in treating the loss of lean body mass in a subject.

[0019] In one exemplary embodiment, the administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation within 3 hours of administration.

[0020] In one exemplary embodiment, the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof.

[0021] In one exemplary embodiment, the subject in need thereof is an elderly human. In one exemplary embodiment, the subject in need thereof has an elevated level of at least one intramuscular signaling protein associated with muscle protein degradation. In one exemplary embodiment, the subject in need thereof has an elevated level of 14-kDa actin fragment. In one exemplary embodiment, the subject in need thereof has an elevated level of ubiquitin. In one exemplary embodiment, the subject in need thereof has an elevated level of MuRF-1.

[0022] In one exemplary embodiment, the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, the subject in need thereof has an elevated level of 14-kDa actin fragment, and the subject in need thereof has undergone hip replacement surgery or has suffered a burn injury within the past two years. In one exemplary embodiment, the burn injury is a third degree burn injury.

[0023] In one exemplary embodiment, the nutritional composition is administered in a single feeding to the subject in need thereof having an elevated level of 14-kDa actin fragment and having undergone hip replacement surgery or having suffered a burn injury within the past two years, and the level of 14-kDa actin fragment is decreased.

[0024] In one exemplary embodiment, the nutritional composition is administered in multiple feedings to the subject in need thereof having an elevated level of 14-kDa actin fragment and having undergone hip replacement surgery or having suffered a burn injury within the past two years, and the level of 14-kDa actin fragment is decreased.

[0025] In one exemplary embodiment, the at least one polyunsaturated fatty acid is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof.

[0026] In one exemplary embodiment, the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid, eicosapentaenoic acid, a-linolenic acid, and combinations thereof, and the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid, arachidonic acid, and combinations thereof.

[0027] In one exemplary embodiment, the at least one monounsaturated fatty acid is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof.

[0028] In one exemplary embodiment, the source of P-hydroxy-P-methylbutyrate is calcium β- hydroxy-P-methylbutyrate monohydrate, and the nutritional composition contains 1-3 grams of calcium P-hydroxy-P-methylbutyrate monohydrate per serving. [0029] In one exemplary embodiment, the nutritional composition further comprises a source of fructooligosaccharides. In certain exemplary embodiments, the nutritional composition contains 2-4 grams of fructooligosaccharides per serving.

[0030] In one exemplary embodiment, the nutritional composition is a liquid and a serving thereof ranges from 115-300 mL. In one exemplary embodiment, the nutritional composition is a reconstitutable powder.

[0031] Numerous aspects of the general inventive concepts will become more readily apparent from the following detailed description of exemplary embodiments, from the claims and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 illustrates a timeline utilized to conduct a comparison between a control (CTL) nutritional composition and an experimental (EXP) nutritional composition with respect to muscle protein degradation in accordance with Example 2 described herein.

DETAILED DESCRIPTION

[0033] While the general inventive concepts are susceptible of embodiment in many different forms, described herein in detail are specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the general inventive concepts. Accordingly, the general inventive concepts are not intended to be limited to the specific embodiments illustrated and described herein.

[0034] Muscle protein balance is a key aspect of overall health, and muscle health in particular. Generally, the metabolic pathways that affect muscle protein balance are tightly regulated. However, such pathways can become dysregulated due to certain disease conditions, prolonged periods of physical inactivity, and the aging process. One particularly negative aspect resulting from such pathway dysregulation is the loss of lean body mass.

[0035] Preserving lean body mass is important for maintaining the strength necessary to carry out activities of daily living, particularly with respect to the elderly population. Additionally, severe loss of lean body mass can result in an increased risk of infection and marked delays in wound healing (Pereira et al., The International Journal of Biochemistry & Cell Biology, Vol. 37: 1948-1961 (2005)). Conventionally, loss of lean body mass has been treated with nutritional interventions designed to enhance muscle protein synthesis. These nutritional interventions may be embodied as oral nutrition supplements that are chronically administered to a subject exhibiting loss of lean body mass. However, such interventions designed for stimulating muscle protein synthesis may be inadequate for effectively preserving lean body mass since the rate of muscle protein degradation is not addressed by such nutritional interventions.

[0036] Numerous studies have been performed to examine the effects of nutritional interventions on stimulating muscle protein synthesis. These studies have generally demonstrated that high levels of protein {e.g., greater than 12% of total caloric intake) or branched chain amino acids are effective for stimulating muscle protein synthesis, particularly in elderly subjects. On the other hand, the anabolic response of skeletal muscle of compromised subjects {e.g., elderly subjects, diseased subjects) is considerably attenuated compared to non- compromised subjects {e.g., young subjects, non-diseased subjects) (Guillet et al, FASEB J, Vol. 18: 1586-1587 (2004)). The observed attenuation of the anabolic response may be due to increased muscle protein degradation via the ubiquitin-proteasome pathway. For example, ubiquitin-proteasome pathway dependent protein degradation has been associated with the loss of lean body mass in diseased states such as chronic obstructive pulmonary disease (COPD) (Debigare et al., Proc. Am. Thorac. Soc, Vol. 7: 84-90 (2010)) and chronic renal failure (Debigare et al, Am. J. Physiol. Renal Physiol., Vol. 285: Fl-8 (2003)). Thus, effective nutritional interventions for preserving lean body mass need to address each component of the muscle protein balance equation.

[0037] Accordingly, methods and nutritional compositions for attenuating muscle protein degradation, preserving lean body mass, or both are provided herein. The exemplary methods and nutritional compositions described herein may be effective for preserving lean body mass by attenuating muscle protein degradation.

[0038] The terminology as set forth herein is for description of the exemplary embodiments only and should not be construed as limiting the disclosure as a whole. Unless otherwise specified, "a," "an," "the," and "at least one" are used interchangeably. Furthermore, as used in the description and the appended claims, the singular forms "a," "an," and "the" are inclusive of their plural forms, unless the context clearly indicates otherwise. Additionally, recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0039] The term "nutritional composition," as used herein, unless otherwise specified, refers to nutritional products in various forms including, but not limited to, liquids, solids, powders, semisolids, semi-liquids, nutritional supplements, and any other nutritional food product known in the art. A nutritional composition in powder form may often be reconstituted to form a nutritional composition in liquid form. In certain exemplary embodiments, the nutritional composition comprises at least one source of protein, at least one source of carbohydrate, and at least one source of fat. The exemplary nutritional compositions disclosed herein are generally suitable for oral consumption by a human.

[0040] The term "subject," as used herein, refers to a mammal including companion animals, livestock, laboratory animals, working animals, sport animals, and humans. In certain exemplary embodiments, the subject is a human.

[0041] The term "subject in need thereof," as used herein, unless otherwise specified, refers to a subject exhibiting increased muscle protein degradation, decreased muscle protein synthesis, loss of lean body mass, or combinations thereof. In certain exemplary embodiments, the increased muscle protein degradation, decreased muscle protein synthesis, or loss of lean body mass may be due to, at least in part, age, physical inactivity, injury, surgery, chronic disease, or combinations thereof. In certain exemplary embodiments, the subject in need thereof is an elderly human, optionally a physically inactive elderly human, optionally a diseased elderly human, and optionally both physically inactive and diseased. In certain exemplary embodiments, the subject in need thereof, is a human that is undergoing a temporary or permanent period of physical inactivity, due to disability, temporary injury, or healing from a surgery. In certain exemplary embodiments, the subject in need thereof has undergone hip surgery. In certain exemplary embodiments, the subject in need thereof has suffered a burn injury, for example, a third degree burn injury. In certain exemplary embodiments, the subject in need thereof is a human undergoing rehabilitation (i.e., physical rehabilitation) due to disease, injury, surgery, hospital admission, and combinations thereof. In certain exemplary embodiments, the subject in need thereof is a human with a chronic disease condition such as, for example, cancer, cachexia, COPD, or end stage renal disease. In certain exemplary embodiments, the subject in need thereof is a human being treated with glucocorticoids for an extended period of time. In certain exemplary embodiments, the subject in need thereof is a human suffering from a muscle disease such as, for example, muscular dystrophy.

[0042] The term "elderly," as used herein, unless otherwise specified, refers to a human of at least 45 years of age, including at least 50 years of age, at least 55 years of age, at least 60 years of age, at least 65 years of age, at least 70 years of age, at least 75 years of age, and including at least 80 years of age or greater. The term "elderly" also includes humans of 45 years of age to 100 years of age, and humans of 55 years of age to 80 years of age.

[0043] The term "lean body mass," as used herein, unless otherwise specified, refers to the amount or size of muscle or muscle groups, as expressed by muscle weight, mass, area, or volume. Muscle mass may also be expressed as total muscle mass, lean body mass of a body compartment such as the leg, or cross-sectional area of a leg or arm compartment. The volume or mass of the muscle can be determined using any known or otherwise effective technique that provides muscle area, volume, or mass such as DEXA, or using visual or imaging techniques such as MRI or CT scans.

[0044] The term "muscle," as used herein, unless otherwise specified, refers to skeletal muscle and other non-skeletal, striated muscles such as diaphragm, extraocular muscle, and so forth.

[0045] The term "intramuscular," as used herein, unless otherwise specified, refers to all cellular parts that comprise a skeletal muscle group, including but not limited to myofibers, myoblasts, satellite cells, neurons, endothelial cells, pericytes, monocytes, macrophages, adipocytes, and fibroblasts.

[0046] The terms "administer," "administering," "administered," and "administration," as used herein, unless otherwise specified, should be understood to include providing a nutritional composition to a subject in need thereof, the act of consuming a nutritional composition (self administration), and combinations thereof. In addition, it should be understood that the methods disclosed herein may be practiced with or without doctor supervision or other medical direction.

[0047] The term "effective amount," as used herein, unless otherwise specified, refers to a sufficient amount of a nutritional composition to exhibit a therapeutic effect (e.g., attenuate muscle protein degradation, preserve lean body mass). The exact amount required to achieve the desired effect will vary from subject to subject, depending on the species, age, weight, lifestyle and general condition of the particular subject.

[0048] The term "HMB," as used herein, unless otherwise specified, refers to -hydroxy- - methylbutyrate (or beta-hydroxy-beta-methylbutyrate), and other suitable sources of HMB such as the free acid, salts (both organic and inorganic), anhydrous salts, esters (including the methyl ester, ethyl ester, phosphoesters, etc.), lactones and other bioavailable forms of HMB suitable for oral administration.

[0049] The term "nutritional liquid," as used herein, unless otherwise specified, refers to nutritional compositions in ready-to-drink liquid form, concentrated liquid form, and nutritional liquids made by reconstituting nutritional powders described herein prior to use. The nutritional liquid may also be formulated as a suspension, an emulsion, a solution, and so forth.

[0050] The terms "nutritional powder" and "reconstitutable powder," as used herein, unless otherwise specified, refers to nutritional compositions in fiowable or scoopable form that can be reconstituted with water or another aqueous liquid prior to consumption and includes both spray dried and drymixed/dryblended powders.

[0051] The term "nutritional semi-solid," as used herein, unless otherwise specified, refers to nutritional compositions that are intermediate in properties, such as rigidity, between solids and liquids. Some semi-solid examples include puddings, yogurts, gels, gelatins, and doughs.

[0052] The term "nutritional semi-liquid," as used herein, unless otherwise specified, refers to nutritional compositions that are intermediate in properties, such as flow properties, between liquids and solids. Some semi-liquid examples include thick shakes, liquid yogurts, and liquid gels. [0053] The term "serving," as used herein, unless otherwise specified, is intended to be construed as any amount which is intended to be consumed by an individual in one sitting or within one hour or less.

[0054] Methods and nutritional compositions for attenuating muscle protein degradation, preserving lean body mass, or both are provided herein. In the exemplary embodiments described herein, the nutritional compositions comprise a source of protein, a source of carbohydrates, a source of fat, a source of beta-hydroxy-beta-methylbutyrate (HMB), at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral. The exemplary methods described herein include administering an effective amount of a nutritional composition to a subject in need thereof. As will be explained in more detail below, the inventors conducted a clinical study and surprisingly discovered that acute (short term) administration of the nutritional compositions described herein effectively attenuates muscle protein degradation, which can result in a preservation of lean body mass, by decreasing the level of at least one intramuscular signaling protein associated with muscle protein degradation.

[0055] In one exemplary embodiment, the nutritional composition comprises a source of HMB. HMB is a metabolite of the essential amino acid leucine, and has the IUPAC name 3- hydroxy-3-methylbutanoic acid. One suitable form of HMB that may be utilized in the exemplary nutritional compositions and methods described herein is the calcium salt of HMB, also designated as Ca-HMB, which is most typically the monohydrate calcium salt. The HMB used in the compositions of the exemplary embodiments can come from any source. Calcium HMB monohydrate (Ca-HMB) is commercially available from Technical Sourcing International (TSI) of Salt Lake City, Utah. Note that the amounts of HMB described herein are based on use of Ca-HMB.

[0056] Although the monohydrate of the calcium salt may be utilized in certain exemplary embodiments of the nutritional compositions and methods disclosed herein, other suitable sources or forms include HMB as a free acid, a salt, an anhydrous salt, an ester, a lactone, or other product forms that provide a bioavailable form of HMB suitable for administration. Non- limiting examples of suitable salts of HMB include HMB salts, hydrated or anhydrous, of sodium, potassium, chromium, calcium, or other non-toxic salt forms.

[0057] In certain exemplary embodiments, the nutritional compositions comprise 0.25 to 10 grams of HMB per serving. In certain exemplary embodiments, the nutritional composition comprises 0.5 grams to 5 grams of HMB per serving. In other exemplary embodiments, the nutritional composition comprises 0.5 to 3 grams or 1 to 3 grams of HMB per serving. In certain exemplary embodiments, the amount of HMB administered via a nutritional composition according to the methods described herein is 1 to 10 grams per day.

[0058] In one exemplary embodiment, the nutritional composition comprises at least one source of protein. In one exemplary embodiment, the at least one source of protein is present in an amount sufficient to provide about 10 to about 25 grams, about 10 to about 20 grams, or about 10 to about 15 grams of protein per serving. Alternatively, the amount of protein present in the nutritional compositions may be expressed in terms of grams of protein per liter (g/L). In such instances, the nutritional compositions comprise a source of protein in an amount sufficient to provide about 40 to about 160 grams or about 40 to about 60 grams of protein per liter of the nutritional composition. Alternatively, the amount of protein may be expressed in terms of the percent of calories of the nutritional composition represented by the protein. In such instances, the nutritional compositions comprise a source of protein in an amount sufficient to provide about 15% to about 75% or about 15% to about 25% of the calories in the nutritional composition.

[0059] Various sources of protein, including one source or more than one source, may be utilized in nutritional compositions according to the exemplary embodiments. Proteins suitable for use in the nutritional compositions according to the embodiments disclosed herein include, but are not limited to, hydrolyzed, partially hydrolyzed or non-hydrolyzed proteins or protein sources, and can be derived from any known or otherwise suitable source such as milk (e.g., casein, whey), animal (e.g., meat, fish), cereal (e.g., rice, corn), vegetable (e.g., soy, pea, potato), or combinations thereof.

[0060] Non-limiting examples of the source of protein include whey protein concentrates, whey protein isolates, whey protein hydrolysates, acid caseins, sodium casemates, calcium casemates, potassium casemates, casein hydrolysates, milk protein concentrates, milk protein isolates, milk protein hydrolysates, skim milk, low fat milk, nonfat dry milk, skim milk powder, condensed skim milk, soy protein concentrates, soy protein isolates, soy protein hydrolysates, pea protein concentrates, pea protein isolates, pea protein hydrolysates, collagen proteins, collagen protein isolates, insect proteins, earthworm proteins, potato protein, rice protein, corn protein, wheat protein, sunflower protein, chickpea protein, quinoa protein, and combinations thereof.

[0061] In one exemplary embodiment, the nutritional composition comprises a source of carbohydrates. In certain exemplary embodiments, the carbohydrates are present in an amount sufficient to provide about 10 to about 100 grams of carbohydrates per serving. The carbohydrates may be from one source or a variety of sources. In certain exemplary embodiments, the nutritional compositions comprise a source of carbohydrates in an amount sufficient to provide about 30 to about 60 grams, about 40 to about 60 grams, or about 50 to about 60 grams of carbohydrates per serving. Alternatively, the amount of carbohydrates present in the nutritional composition may be expressed in terms of grams of carbohydrates per liter (g/L). In such instances, the nutritional composition comprises a source of carbohydrates in an amount sufficient to provide about 125 to about 255 grams, or about 150 to about 230 grams of carbohydrates per liter of the nutritional composition. Alternatively, the amount of carbohydrates may be expressed in terms of the percent of calories of the nutritional composition represented by the carbohydrates. In such instances, the nutritional composition comprises a source of carbohydrates in an amount sufficient to provide about 40% to about 75% or about 50% to about 65% of the calories in the nutritional composition.

[0062] The at least one source of carbohydrates may be simple, complex, or variations or combinations thereof. Generally, any source of carbohydrates may be used so long as it is suitable for use in oral nutritional compositions and is otherwise compatible with any other selected ingredient or feature present in the nutritional composition. Non-limiting examples of a source of carbohydrates which may be suitable for use in the exemplary nutritional compositions described herein include maltodextrin, hydrolyzed or modified starch or cornstarch, glucose polymers, corn syrup, corn syrup solids, rice-derived carbohydrates, sucrose, glucose, fructose, lactose, high fructose corn syrup, honey, sugar alcohols (e.g., maltitol, erythritol, sorbitol), isomaltulose, sucromalt, pullulan, potato starch, and other slowly-digested carbohydrates, dietary fibers including, but not limited to, oat fiber, soy fiber, gum arabic, sodium carboxymethylcellulose, methylcellulose, guar gum, gellan gum, locust bean gum, konjac flour, hydroxypropyl methylcellulose, tragacanth gum, karaya gum, gum acacia, chitosan, arabinoglactins, glucomannan, xanthan gum, alginate, pectin, low and high methoxy pectin, cereal beta-glucans (e.g., oat beta-glucan, barley beta-glucan), carrageenan and psyllium, Fibersol™, other resistant starches, and combinations thereof.

[0063] In certain exemplary embodiments, the nutritional composition comprises a source of fructooligosaccharides (FOS). The FOS, in certain exemplary embodiments, may be natural or synthetic, short-chain or long-chain, and combinations thereof. Natural sources of FOS include, but are not limited to, Jerusalem artichoke, chicory root, yacon, bananas, onions, garlic, asparagus, barley, wheat, jicama, and leeks. Suitable synthetic sources of FOS include Actilight® (Beghin-Meiji, Marckolsheim, France) and scFOS® (Ingredion, Inc., Westchester, Illinois). In certain exemplary embodiments, the nutritional compositions comprise a source of FOS in an amount sufficient to provide about 1 to about 10 grams, about 1 to about 5 grams, or about 2 to about 4 grams of FOS per serving. Alternatively, the amount of FOS present in the exemplary nutritional compositions may be expressed in terms of grams of FOS per liter (g/L). In such instances, the nutritional composition comprises a source of FOS in an amount sufficient to provide about 4 to about 50 grams or about 4 to about 25 grams of FOS per liter of the nutritional composition.

[0064] In one exemplary embodiment, the nutritional composition comprises at least one source of fat. In certain exemplary embodiments, the source of fat is present in an amount sufficient to provide about 5 to about 20 grams or about 5 to about 15 grams of fat per serving. Alternatively, the amount of fat present in the exemplary nutritional compositions may be expressed in terms of grams of fat per liter (g/L). In such instances, the nutritional composition comprises a source of fat in an amount sufficient to provide about 20 to about 85 grams or about 25 to about 50 grams of fat per liter of the nutritional composition. Alternatively, the amount of fat may be expressed in terms of the percent of calories of the nutritional composition represented by the fat. In such instances, the nutritional composition comprises a source of fat in an amount sufficient to provide about 10% to about 75% or about 20% to about 40% of the calories in the nutritional composition.

[0065] Non-limiting examples of fats suitable for use in the exemplary nutritional compositions include canola oil, corn oil, coconut oil, fractionated coconut oil, soy oil, olive oil, safflower oil, high GLA safflower oil, high oleic safflower oil, MCT oil (medium chain triglycerides), sunflower oil, high oleic sunflower oil, palm and palm kernel oils, palm olein, marine oils, cottonseed oils, algal and fungal derived oils, and combinations thereof.

[0066] In one exemplary embodiment, the nutritional composition comprises at least one polyunsaturated fatty acid (PUFA). In certain exemplary embodiments, the at least one PUFA is provided by one or more sources of fat including, but not limited to, marine oil, egg derived oils, fungal oil, algal oil, and combinations thereof. In one exemplary embodiment, the at least one PUFA is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof. In certain exemplary embodiments, the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), a-linolenic acid, and combinations thereof. In certain exemplary embodiments, the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid (GLA), arachidonic acid, and combinations thereof. In certain exemplary embodiments, the nutritional compositions comprise about 1 to about 10 grams or about 3 to about 5 grams of at least one PUFA per serving. Alternatively, the amount of PUFA present in the exemplary nutritional compositions may be expressed in terms of grams of PUFA per liter (g/L). In such instances, the nutritional composition comprises about 4 to about 50 grams or about 12 to about 25 grams of PUFA per liter of the nutritional composition.

[0067] In one exemplary embodiment, the nutritional composition comprises at least one monounsaturated fatty acid (MUFA). In certain exemplary embodiments, the at least one MUFA is provided by one or more sources of fat including, but not limited to, coconut oil, soybean oil, avocado oil, canola oil, olive oil, peanut oil, safflower oil, sunflower oil, and combinations thereof. In certain exemplary embodiments, the at least one MUFA is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof. In certain exemplary embodiments, the nutritional compositions comprise about 1 to about 10 grams or about 4 to about 8 grams of at least one MUFA per serving. Alternatively, the amount of MUFA present in the exemplary nutritional compositions may be expressed in terms of grams of MUFA per liter (g/L). In such instances, the nutritional composition comprises about 4 to about 50 grams or about 15 to about 40 grams of MUFA per liter of the nutritional composition.

[0068] In one exemplary embodiment, the nutritional composition comprises at least one vitamin and at least one mineral. For example, in certain exemplary embodiments, the nutritional composition comprises vitamins and minerals that have antioxidant properties such as vitamin E, Vitamin C, selenium, molybdenum, and combinations thereof. In certain exemplary embodiments, the nutritional composition comprises vitamin D, including vitamin D₂ and vitamin D₃, which promotes intestinal absorption of calcium and phosphate. In certain exemplary embodiments, the nutritional composition comprises about 125 to about 200 IUs or about 150 to about 175 IUs of vitamin D (1 IU of vitamin D is equivalent to 0.025 micrograms of vitamin D) per serving.

[0069] In certain exemplary embodiments, the nutritional compositions may include other vitamins and related nutrients, non-limiting examples of which include vitamin A, vitamin A palmitate, vitamin E acetate, vitamin C palmitate (ascorbyl palmitate), vitamin K, thiamine, riboflavin, pyridoxine, vitamin Bi₂, carotenoids (e.g., beta-carotene, zeaxanthin, lutein, lycopene), niacin, folic acid, pantothenic acid, biotin, choline, inositol, salts and derivatives thereof, and combinations thereof. In certain exemplary embodiments, the nutritional compositions comprise any of a variety of additional minerals, non-limiting examples of which include calcium, potassium, iodine, phosphorus, magnesium, iron, zinc, manganese, copper, sodium, chromium, chloride, and combinations thereof.

[0070] The exemplary nutritional compositions can provide up to about 500 kcal of energy per serving, including from 240 to 500 kcal, from 275 to 450 kcal, from 300 to 400 kcal, from 325 to 375 kcal, or from 325 to 350 kcal per serving.

[0071] In one exemplary embodiment, the nutritional composition comprises one or more functional ingredients that promote muscle health. For example, in certain exemplary embodiments, the one or more functional ingredients are selected from at least one of: a branched-chain amino acid selected from the group consisting of leucine, isoleucine, valine, metabolites of any of the foregoing branched-chain amino acids, and combinations thereof; a- ketoisocaproic acid (KIC); a-hydroxyisocaproic acid (HICA); β-alanine; a green tea catechin selected from the group consisting of epigallocatechin gallate, epigallocatechin, epicatechin, catechin, epicatechin gallate, and metabolites thereof; creatine; carnitine; carnosine; taurine; anserine; one or more of the proteinogenic amino acids; curcumin; green tea extract; plum extract; resveratrol; a-tocopherol; and combinations thereof.

[0072] In one exemplary embodiment, the nutritional composition may comprise other optional ingredients that may modify the physical, chemical, aesthetic or processing characteristics of the nutritional composition, or serve as additional nutritional components. Many such optional ingredients are known or otherwise suitable for use in medical food or other nutritional products and may also be used in the nutritional compositions described herein, provided that such optional ingredients are safe for oral administration and are compatible with the essential and other ingredients in the selected product form.

[0073] In one exemplary embodiment, the nutritional composition may comprise at least one sweetening agent. In certain exemplary embodiments, the at least one sweetening agent is a sugar alcohol such as maltitol, erythritol, sorbitol, xylitol, mannitol, isomalt, and lactitol, or at least one artificial or high potency sweetener such as acesulfame K, aspartame, sucralose, saccharin, stevia, and tagatose, and combinations thereof. The sweetening agents, especially as a combination of a sugar alcohol and an artificial sweetener, can be useful in formulating liquid nutritional compositions having a desirable favor profile. These sweetener combinations can also be effective in masking undesirable flavors, for example, as sometimes associated with the addition of vegetable proteins to a liquid nutritional composition.

[0074] In one exemplary embodiment, the nutritional composition may comprise a flowing agent or anti-caking agent to retard clumping or caking of a nutritional powder embodiment over time and to make the nutritional powder flow easily from its container. Any flowing or anti- caking agents that are known or otherwise suitable for use in a nutritional powder or product form are suitable for use herein, non-limiting examples of which include tricalcium phosphate, silicates, and combinations thereof. The concentration of the flowing agent or anti-caking agent will often vary depending upon the product form, the other selected ingredients, the desired flow properties, and so forth.

[0075] In one exemplary embodiment, the nutritional composition may comprise a stabilizer. Any stabilizer that is known or otherwise suitable for use in a nutritional composition may also be suitable for use herein, non-limiting examples of which include gums such as xanthan gum and locust bean gum.

[0076] In certain exemplary embodiments, the nutritional composition optionally includes one or more masking agents to reduce or otherwise obscure the development of any residual bitter flavors and after taste in the nutritional composition over time. Suitable masking agents include natural and artificial sweeteners, sodium sources such as sodium chloride, and hydrocolloids such as guar gum, xanthan gum, carrageenan, gellan gum, and combinations thereof. The amount of masking agent used will often vary depending upon the particular masking agent selected, other ingredients in the formulation, and other formulation or product target variables.

[0077] Exemplary embodiments of the nutritional compositions may also be substantially free of any optional or selected essential ingredient or feature described herein, provided that the remaining nutritional product still contains some of the required ingredients or features as described herein. In this context, and unless otherwise specified, the term "substantially free" means that the selected nutritional product contains less than a functional amount of the noted optional or selected essential ingredient, typically less than 1.0%, including less than 0.5%, less than 0.1%), and zero percent, by weight of such optional or selected essential ingredient.

[0078] In one exemplary embodiment, the nutritional composition is formulated in a product form suitable for oral administration. Oral administration, as defined herein, includes any form of administration in which the nutritional composition is introduced into the subject's digestive system, including the stomach and small intestine. For example, oral administration includes nasogastric intubation, in which a tube is run from through the nose to the stomach of the subject to administer food or drugs. Suitable forms of such nutritional compositions may include liquids, powders, solids, semi-solids, semi-liquids compositions, provided that such a formulation allows for the effective delivery and consumption of the nutritional composition. [0079] In one exemplary embodiment, the nutritional composition may be a nutritional solid, nutritional liquid, nutritional semi-solid, nutritional semi-liquid, or nutritional powder. Examples of nutritional composition forms suitable for use herein include snack and meal replacement products, including those formulated as bars; sticks; cookies; breads, cakes, or other baked goods; frozen liquids; candy; breakfast cereals; powders, granulated solids, or other particulates; snack chips or bites; frozen or retorted entrees; and so forth. In certain exemplary embodiments, the nutritional composition can be in a form that falls between solid and liquid, such as puddings, yogurts, or gels. In certain exemplary embodiments, when the nutritional composition is a solid product, a serving thereof may be about 25 to about 150 grams.

[0080] Examples of suitable liquid nutritional compositions include snack and meal replacement products, hot or cold beverages, carbonated or non-carbonated beverages, juices or other acidified beverages, milk or soy-based beverages, shakes, coffees, teas, and so forth. These liquid compositions are most typically formulated as suspensions or emulsions, but can also be formulated in any other suitable form such as clear liquids, substantially clear liquids, liquid gels, and so forth. In certain exemplary embodiments, when the nutritional composition is a liquid nutritional product, a serving thereof may be about 1 15 to about 500 milliliters. In certain other exemplary embodiments, when the nutritional composition is a liquid, the serving is 237 milliliters (~8 fl. oz.). In other exemplary embodiments, when the nutritional composition is a liquid, the serving is about 177 to about 414 milliliters (~6 fl. oz. to ~14 fl. oz.) or about 207 to about 296 milliliters (~7 fl. oz. to ~10 fl. oz.).

[0081] The exemplary nutritional liquids may be prepared by any process or method (now known or known in the future) suitable for making a selected product form, such as a nutritional solid, a nutritional powder, or a nutritional liquid. Many such techniques may be known for any given product form, such as nutritional liquids or nutritional powders, and can readily be applied by one of ordinary skill in the art to the various exemplary embodiments described herein.

[0082] In one suitable manufacturing process, a nutritional liquid is prepared using at least three separate slurries, including a protein-in-fat (PIF) slurry, a carbohydrate-mineral (CHO- MIN) slurry, and a protein-in-water (PIW) slurry. The PIF slurry is formed by heating and mixing selected oils (e.g. , canola oil, corn oil) and then adding an emulsifier (e.g. , soy lecithin), fat soluble vitamins, and a portion of the total protein (e.g., milk protein concentrate) with continued heat and agitation. The CHO-MIN slurry is formed by adding with heated agitation to water: minerals (e.g., potassium citrate, magnesium phosphate, calcium carbonate), trace minerals and ultra trace minerals (e.g., TM/UTM premix), thickening or suspending agents (e.g., gellan gum, carrageenan), and HMB. The resulting CHO-MIN slurry is held for 10 minutes with continued heat and agitation before adding additional minerals (e.g., potassium chloride, magnesium carbonate, potassium iodide), and carbohydrates (e.g., fructooligosaccharide, sucrose). The PIW slurry is then formed by mixing with heat and agitation the remaining protein (e.g. , sodium caseinate, soy protein isolate, whey protein concentrate) into water.

[0083] The resulting slurries are then blended together with heated agitation and the pH adjusted to a desired range, typically from 6.6-7.0, after which the composition is subjected to high-temperature short-time (HTST) processing during which the composition is heat treated, emulsified and homogenized, and then allowed to cool. Water soluble vitamins and ascorbic acid are added, the pH is again adjusted to the desired range (if necessary), flavors are added, and water is added to achieve a desired total solid level. The composition is then aseptically packaged to form an aseptically packaged nutritional emulsion, or the composition is added to retort stable containers and then subjected to retort sterilization to form retort sterilized nutritional emulsions.

[0084] The manufacturing processes for the nutritional emulsions may be carried out in ways other than those set forth herein without departing from the spirit and scope of the present general inventive concepts. The present embodiments are, therefore, to be considered in all respects illustrative and not restrictive with changes and equivalents intended to fall within the general inventive concepts.

[0085] A nutritional powder, such as a spray dried nutritional powder, may be prepared by any combination of known or otherwise effective techniques suitable for making and formulating a spray dried nutritional powder. The spray drying step may likewise include any spray drying technique that is known for or otherwise suitable for use in the production of nutritional powders. Many different spray drying methods and techniques are known for use in the nutrition field, of which many are suitable for use in the manufacture of the spray dried nutritional powders herein. [0086] One method of preparing an exemplary spray dried nutritional powder comprises forming and homogenizing an aqueous slurry or liquid comprising HMB, protein, carbohydrates, and fat, and then spray drying the slurry or liquid to produce a spray dried nutritional powder. The method may further comprise the step of spray drying, dry mixing, or otherwise adding additional nutritional ingredients, including any one or more of the ingredients described herein, to the spray dried nutritional powder. In certain exemplary embodiments, the methods of manufacture utilize calcium HMB. As previously discussed, the calcium HMB is most typically formulated as a monohydrate salt.

[0087] Nutritional compositions according to the exemplary embodiments are useful for providing sole, primary, or supplemental sources of nutrition, as well as providing one or more of the benefits as described herein such as attenuating muscle protein degradation, preserving lean body mass, or both.

[0088] In one exemplary embodiment, a nutritional composition for use in attenuating protein degradation in a subject in need thereof and a method of attenuating protein degradation in a subject in need thereof is provided. The method of attenuating muscle protein degradation in a subject in need thereof, according to one exemplary embodiment, comprises administering an effective amount of a nutritional composition to the subject in need thereof. The nutritional compositions for use in attenuating protein degradation in a subject in need thereof and in the exemplary method comprise: a source of fat, a source of protein, a source of carbohydrates, a source of P-hydroxy-P-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral. The nutritional compositions further have from 10-25 grams of protein and from 240-500 kcal per serving. Accordingly, any of the previously described exemplary nutritional compositions are for use in attenuating protein degradation in a subject in need thereof and are also for use in the exemplary methods described herein. Administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby attenuating muscle protein degradation in the subject. [0089] In one exemplary embodiment, a nutritional composition for use in treating the loss of lean body mass in a subject in need thereof and a method of preserving lean body mass in a subject in need thereof is provided. The method comprises administering an effective amount of a nutritional composition to the subject in need thereof. The nutritional compositions for use in treating the loss of lean body mass in a subject in need thereof and in the exemplary method comprise: a source of fat, a source of protein, a source of carbohydrates, a source of β-hydroxy- β-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral. The nutritional composition further has from 10- 25 grams of protein and from 240-500 kcal per serving. Accordingly, any of the previously described exemplary nutritional compositions are for use in treating the loss of lean body mass in a subject in need thereof and are also for use in the exemplary methods described herein. Administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby preserving lean body mass in the subject.

[0090] Certain intramuscular signaling proteins are associated with muscle protein degradation, apoptosis, or both via the ubiquitin-proteasome system. Accordingly, changes in the concentration of such signaling proteins can be used to evaluate whether a particular intervention attenuates or otherwise has an effect on muscle protein degradation. In certain exemplary embodiments, the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof. In yet other exemplary embodiments, the at least one intramuscular signaling protein associated with muscle protein degradation may include one or more of 19S proteasome, 20S proteasome, C2 proteasomal unit, caspase-3, caspase-8, caspase-9, calpain 3, cathepsin L, LC3B-II, p62, or ubiquitinated proteins.

[0091] A 14-kDa actin fragment has been reported as a diagnostic marker for increased muscle protein degradation in subjects with catabolic conditions (Workeneh et al., J. Am. Soc. Nephrol. Vol. 17: 3233-3239 (2006)). The characteristic 14-kDa actin fragment results from the breakdown of actomyosin, a constituent of muscle fiber responsible for muscular contraction. Increased muscle protein degradation and 14-kDa actin fragment levels have been observed in subjects that have undergone hip replacement surgery or that have suffered a burn injury, such as a third degree burn injury (Workeneh et al., J. Am. Soc. Nephrol. Vol. 17: 3233-3239 (2006)).

[0092] The ubiquitin-proteasome system is a critical pathway leading to muscle protein degradation in many conditions, including severe catabolic states (e.g., cancer cachexia, sepsis, etc.), sarcopenia and fasting (Sakuma et al., J. Cachexia Sarcopenia Muscle, Vol. 3: 77-94 (2012)). Ubiquitin and E-3 ligases (including MuRF-1 and MAFbx) are components of the ubiquitin-proteasome system, and elevated levels of these proteins serve as markers for increased muscle protein degradation.

[0093] Besides the ubiquitin-proteasome pathway of muscle protein degradation, apoptosis is another pathway that leads to muscle protein degradation. Bax and Bcl-2 are two signaling proteins involved in the apoptosis pathway, with Bax being pro-apoptotic and Bcl-2 being anti- apoptotic. Additionally, the ratio of Bax to Bcl-2 may be used as a marker for apoptosis.

[0094] As previously mentioned, the exemplary nutritional compositions and exemplary methods are provided to attenuate muscle protein degradation, to preserve lean body mass, or both in a subject in need thereof. In one exemplary embodiment, the subject in need thereof is an elderly human. In one exemplary embodiment, the subject in need thereof has an elevated level of at least one intramuscular signaling protein associated with muscle protein degradation. In one exemplary embodiment, the subject in need thereof has an elevated level of 14-kDa actin fragment. In one exemplary embodiment, the subject in need thereof has an elevated level of ubiquitin. In one exemplary embodiment, the subject in need thereof has an elevated level of MuRF-1. In one exemplary embodiment, the subject in need thereof has an elevated level of 14- kDa actin fragment, an elevated level of ubiquitin, and/or an elevated level of MuRF-1. In another exemplary embodiment, the subject in need thereof has an elevated level of 14-kDa actin fragment and has undergone hip replacement surgery within the past two years. In yet another exemplary embodiment, the subject in need thereof has an elevated level of 14-kDa actin fragment and has suffered a burn injury. In another exemplary embodiment, the subject in need thereof has suffered a third degree burn injury. In another exemplary embodiment, the subject in need thereof has suffered a burn injury within the past two years. [0095] In certain exemplary embodiments of the methods described herein, the administration (or consumption) of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation within 3 hours of administration. Accordingly, the exemplary nutritional compositions and methods can be effective almost immediately for attenuating muscle protein degradation and for preserving lean body mass in instances where the subject in need thereof exhibits acute muscle protein degradation or acute loss of lean body mass (e.g., immediately after burn injury), as well as chronic muscle protein degradation and chronic loss of lean body mass (e.g., sarcopenia, chronic disease, during rehabilitation after a hip replacement surgery). Moreover, the exemplary nutritional compositions and methods can be effective almost immediately for attenuating muscle protein degradation and for preserving lean body mass by administering an effective amount of the nutritional composition to the subject in need thereof in a single feeding, which is discussed in detail below.

[0096] In certain exemplary embodiments, attenuating muscle protein degradation also includes maintaining the levels of the at least one intramuscular signaling protein associated with protein degradation. In other words, the exemplary nutritional compositions and methods described herein can be effective almost immediately for preventing an increase in the levels of the at least one intramuscular signaling protein associated with protein degradation. Additionally, the exemplary nutritional compositions and methods can be effective almost immediately for preventing an increase in the levels of the at least one intramuscular signaling protein associated with protein degradation by administering an effective amount of the nutritional composition to a subject in need thereof in a single feeding, which is discussed in detail below.

[0097] The levels of the at least one intramuscular signaling protein associated with muscle protein degradation may be determined by any suitable method (now known or known in the future) for measuring protein levels. For example, in certain exemplary embodiments, the levels of the at least one intramuscular signaling protein associated with muscle protein degradation may be determined by obtaining muscle tissue samples (e.g., muscle biopsy) and performing assays (e.g., ELISA, western blot, quantitative reverse transcription-polymerase chain reaction, R ase protection assay) to measure protein levels in the muscle tissue. Moreover, muscle tissue samples can be obtained at different time points and subsequently assayed to calculate the change (e.g., decrease or increase) in the levels of the proteins of interest between the time points.

[0098] Similarly, the lean body mass of a subject may be determined by any suitable method (now known or known in the future) for determining a subject's lean body mass. For example, lean body mass may be determined by methods including, but not limited to, bioelectrical impedance analysis (BIA), air displacement plethysmography (ADP), hydrodensitometry, dual energy x-ray absorptiometry (DEXA), densitometry, magnetic resonance imaging (MRI), computed tomography (CT), and combinations thereof.

[0099] In certain exemplary embodiments, the levels of the at least one intramuscular signaling protein associated with muscle protein degradation of the subject in need thereof is determined in a fasted state to establish fasted state levels of the at least one intramuscular signaling protein associated with muscle protein degradation. The term "fasted state," as used herein, refers to a subject in need thereof who has abstained from eating, chewing gum, drinking liquids, except water, and the like for at least 10 hours. The fasted state level of one or more intramuscular signaling proteins may serve, in certain exemplary embodiments, as a baseline level for purposes of comparing intramuscular signaling protein levels after the subject in need thereof has consumed an exemplary nutritional composition described herein. Similarly, in certain exemplary embodiments, the levels of the at least one intramuscular signaling protein associated with muscle protein degradation of the subject in need thereof is determined in a fed state to establish fed state levels of the at least one intramuscular signaling protein associated with muscle protein degradation. The term "fed state," as used herein, refers to a point in time immediately after a subject in need thereof has consumed an effective amount of an exemplary nutritional composition as described herein within a period of no more than five hours, or no more than three hours. The fed state level of one or more intramuscular signaling proteins may serve, in certain exemplary embodiments, as a final level for purposes of comparing intramuscular signaling protein levels. Accordingly, comparing the fasted state level to the fed state level will provide an indication as to whether the levels of one or more intramuscular signaling proteins associated with muscle protein degradation have increased or decreased. [00100] In certain exemplary embodiments, attenuating muscle protein degradation is indicative of preserving lean body mass. In certain exemplary embodiments, preserving lean body mass means the lean body mass of a subject decreases by no more than a certain percentage or, alternatively, the lean body mass of the subject is maintained within a certain percentage of the subject's lean body mass prior to consumption of the nutritional composition. In certain exemplary embodiments, a pre-administration measurement of lean body mass takes place within 1 week prior to initiation of the administration of the nutritional compositions disclosed herein. In certain such embodiments, the measurement takes place within 1-7 days prior to initiation of the administration. In other exemplary embodiments, preserving lean body mass means an increase in the lean body mass of the subject as compared to the lean body mass maintained by the subject without administration of the nutritional composition. Notably, it is intended that preserving lean body mass by consumption of one or more of the exemplary nutritional compositions described herein may be illustrated via an animal study, wherein the animals consume an equivalent amount of the same nutritional composition for a certain time period.

[00101] In certain exemplary embodiments of the uses and methods described herein, the nutritional composition is administered in a single feeding, and the level of at least one intramuscular protein associated with muscle protein degradation is decreased. The phrase "single feeding," as used herein, refers to the administration of an amount of nutritional composition between 3 and 7 mL/kg FFM (FFM = fat free mass of the subject) over a period of no more than 3 hours. The FFM of a subject may be determined by any number of methods and techniques known to those of skill in the art such as by bioelectrical impedance analysis (BIA), air displacement plethysmography (ADP), hydro densitometry, dual energy x-ray absorptiometry (DEXA), densitometry, magnetic resonance imaging (MRI), computed tomography (CT), and combinations thereof. By way of example, for a subject having a fat free mass of 50 kg, consumption of between 150 and 350 mL of the nutritional composition within 3 hours would constitute a single feeding. Additionally, it should be understood that the total amount consumed during the single feeding could be divided into one, two, three, four, or more discrete amounts for consumption, and the amounts could be the same or different. In certain exemplary embodiments, a single feeding may be one serving, less than one serving, or more than one serving of the nutritional composition. In certain exemplary embodiments, the nutritional composition is administered in multiple feedings. The phrase "multiple feedings," as used herein, refers to multiple (e.g., two, three, four) instances of single feedings occurring within a twenty-four hour period.

[00102] In certain exemplary embodiments, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, and the level of 14-kDa actin fragment decreases from a fasted state to a fed state. In certain exemplary embodiments, the nutritional composition is administered in a single feeding, and the level of 14-kDa actin fragment is decreased. Such result indicates that acute administration of the exemplary nutritional compositions described herein is effective for attenuating muscle protein degradation, for preserving lean body mass, or both. In certain other exemplary embodiments, the nutritional composition is administered in multiple feedings, and the level of 14-kDa actin fragment is decreased.

[00103] In certain exemplary embodiments, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is ubiquitin, and the level of ubiquitin decreases from a fasted state to a fed state. In certain exemplary embodiments, the nutritional composition is administered in a single feeding, and the level of ubiquitin is decreased. Such result indicates that acute administration of the exemplary nutritional compositions described herein is effective for attenuating muscle protein degradation, for preserving lean body mass, or both. In certain other exemplary embodiments, the nutritional composition is administered in multiple feedings, and the level of ubiquitin is decreased.

[00104] In certain exemplary embodiments, the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is MuRF-1 , and the level of MuRF-1 decreases from a fasted state to a fed state. In certain exemplary embodiments, the nutritional composition is administered in a single feeding, and the level of MuRF-1 is decreased. Such result indicates that acute administration of the exemplary nutritional compositions described herein is effective for attenuating muscle protein degradation, for preserving lean body mass, or both. In certain other exemplary embodiments, the nutritional composition is administered in multiple feedings, and the level of MuRF-1 is decreased. [00105] In certain exemplary embodiments of the uses and methods described herein, the effective amount of the nutritional composition is administered to the subject in need thereof for a period of at least three weeks. For example, the nutritional composition, in certain exemplary embodiments, may be administered to the subject in need thereof for a period of three to eight weeks, three weeks to six months, three weeks to nine months, or three weeks to one year or even longer. In certain other exemplary embodiments, the effective amount of the nutritional composition is administered to the subject in need thereof for a period of time of up to three weeks, such as one day, two days, three days, four days, five days, six days, one week, ten days, two weeks, or three weeks.

[00106] In certain exemplary embodiments, the effective amount of the nutritional composition can be administered to the subject in need thereof in one, two, three, four, or more servings per day of administration. In certain other exemplary embodiments, the effective amount of the nutritional composition is administered to the subject in need thereof in two servings per day of administration.

[00107] In accordance with certain exemplary embodiments of the uses and methods disclosed herein, the effective amount of the nutritional composition can be administered to the subject in need thereof one or more times per day for a period of up to three weeks, or for a period of at least three weeks, to achieve the desired effect. For example, in certain exemplary embodiments, the effective amount of the nutritional composition can be administered to the subject in need thereof every day for at least three weeks, every day for at least four weeks, every day for at least eight weeks, every day for at least six months, or every day for a year or more. As another example, the effective amount of the nutritional composition can be administered to the subject in need thereof twice a day for at least three weeks, twice a day for at least four weeks, twice a day for at least eight weeks, twice a day for at least six months, or twice a day for a year or more. Within the context of providing a serving to the subject in need thereof, every day is intended to reflect a subject who has been instructed to be administered the exemplary nutritional composition as described herein every day and who actually is administered the nutritional composition for at least 70% (and in certain other exemplary embodiments at least 90%) of the days during the period of administration. [00108] In certain exemplary embodiments, the nutritional composition is acutely administered to the subject in need thereof. The phrases "acutely administered," "acute administration," or "acutely administering," as used herein, refer to administering an effective amount of the exemplary nutritional composition to the subject in need thereof on a non-regular basis. Acute administration may be a single serving, or multiple servings, administered over a relatively short time period, such as up to three weeks, including one day, two days, three days, five days, one week, ten days, two weeks, or three weeks.

[00109] In certain exemplary embodiments, the nutritional composition is chronically administered to the subject in need thereof. "Chronically administering," as used herein, refers to regular administration which is provided indefinitely or to regular administration for a significant period of time. For example, in certain exemplary embodiments, chronic administration can include regular administration for at least three weeks, regular administration for at least one month, regular administration for at least 6 weeks, regular administration for at least two months, regular administration for at least 3 months, regular administration for at least 4 months, regular administration for at least 5 months, regular administration for at least 6 months, or regular administration for at least 9 months. In other exemplary embodiments, the chronic administration refers to regular administration for at least 1 year, regular administration for at least 1.5 years, regular administration for at least 2 years, or regular administration for more than 2 years. "Regular administration," as used herein, refers to administration according to a schedule whereby the subject in need thereof will receive the exemplary nutritional composition at regular intervals.

[00110] As used herein, "regular intervals" refers to administration in a repeating, periodic fashion where the time between administrations is approximately (or intended to be approximately) the same. In various exemplary embodiments, administration at regular intervals includes daily administration or weekly administration. In other exemplary embodiments, administration at regular intervals includes administration 1-2 times per week, administration 1-3 times per week, administration 2-3 times per week, administration 1-4 times per week, administration 1-5 times per week, administration 2-5 times per week, administration 3-5 times per week, administration 1-6 times per week, administration 1-7 times per week, administration 2-6 times per week, administration 2-7 times per week, administration 1-2 times per day, administration 1-3 times per day, administration 1-4 times per day, administration 2-3 times per day, administration 2-4 times per day, administration 3-4 times per day, administration 2-5 times per day, administration 3-5 times per day, or administration 4-5 times per day.

EXAMPLES

[00111] The following examples illustrate certain exemplary embodiments of the methods and nutritional compositions disclosed herein. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present disclosure, as many variations thereof are possible without departing from the spirit and scope of the disclosure.

EXAMPLE 1

[00112] An exemplary nutritional composition in the form of a nutritional liquid emulsion suitable for use in the methods disclosed herein is described in Example 1, with the specific ingredients provided immediately thereafter.

[001 13] The exemplary nutritional composition described in Example 1 includes Water, Corn Maltodextrin, Sugar (Sucrose), Canola Oil, Sodium Caseinate, Milk Protein Concentrate, Corn Oil, Short-Chain Fructooligosaccharides, Soy Protein Isolate, Potassium Citrate, Calcium Beta- Hydroxy-Beta-Methylbutyrate (Ca-HMB), and less than 0.5% of the following: Whey Protein Concentrate, Natural & Artificial Flavors, Magnesium Phosphate, Soy Lecithin, Sodium Phosphate, Potassium Phosphate, Choline Chloride, Ascorbic Acid, Calcium Carbonate, Potassium Chloride, L-Carnitine, Carrageenan, Ferrous Sulfate, dl-Alpha-Tocopheryl Acetate, Zinc Sulfate, Gellan Gum, Niacinamide, Manganese Sulfate, Calcium Pantothenate, Cupric Sulfate, Vitamin A Palmitate, Thiamine Chloride Hydrochloride, Pyridoxine Hydrochloride, Riboflavin, Folic Acid, Chromium Chloride, Biotin, Sodium Molybdate, Sodium Selenate, Potassium Iodide, Phylloquinone, Vitamin D₃, and Cyanocobalamin. Example 2

[00114] Example 2 describes a study that was conducted to determine the effects on muscle protein degradation after consumption of: (1) a standard, commercially-available oral nutrition supplement (CTL); and (2) an exemplary nutritional composition (EXP) as described herein. Twenty-seven subjects participated in the study. The twenty-seven subjects were elderly, human men, with ages ranging from 60-82 years old.

[00115] Investigational Plan

[00116] The study was a prospective, randomized, double-blinded, counterbalanced crossover clinical trial. During the initial screening visit (Visit 1), subjects underwent a nonfasted blood draw and were screened and tested for height, weight, body mass index, handgrip strength, gait speed, body composition, muscle mass, and bone density to clearly delineate the sample demographics. During the second and third experimental visits (Visit 2 and Visit 3), eligible subjects experienced two identical testing conditions separated by five to fourteen days with the only difference between conditions being the consumption of CTL or EXP (in random order). At Visits 2 and 3, after a first muscle biopsy (fasted state muscle biopsy) was taken from the vastus lateralis, the subject consumed the tested product in 18 small boluses over a three hour period (one bolus consumed approximately every ten minutes). A second muscle biopsy (fed state muscle biopsy) was taken from the same leg within 5-10 cm from the original biopsy site. Also at Visit 2, a fasting blood sample was taken to measure total protein, albumin, prealbumin, hemoglobin, hematocrit, RBC, WBC, differentials, platelet count, glucose, BUN, creatinine, sodium, potassium, chloride, calcium, magnesium, phosphorus, uric acid, total cholesterol, triglycerides, SGOT, SGPT, LDH, total bilirubin, thyroid stimulating hormone, vitamin B12 and folic acid, serum 25-OH vitamin D, serum PTH, insulin, sex hormone binding globulin, testosterone, progesterone, 17P-estradiol, and high-sensitivity C-reactive protein.

[00117] The study evaluated changes in skeletal muscle proteins involved in catabolic signaling pathways, including ubiquitin-proteasome-dependent proteolysis and apoptosis of skeletal muscle {e.g., ubiquitination, actin fragmentation, MuRF-1, MAFbx, bax, bcl2, and Fox03). In this repeated measures crossover design, the subjects served as their own controls by experiencing both the control (CTL) and experimental (EXP) conditions separated by a 5- to 14- day washout period. Additionally, the study evaluated the changes in proteolysis/apoptosis markers from a basal state (i.e., fasted state) to a fed state during both the control (CTL) and experimental (EXP) conditions.

[00118] Treatments Administered

[00119] Treatment orders were assigned using a prospective computer generated randomization plan. All subjects received both the CTL composition and the EXP composition in random order: one at Visit 2 and the other at Visit 3. Both compositions were administered to the subjects orally. Additionally, both the CTL composition and the EXP composition were administered in 18 small oral boluses according to volume over a 3 -hour feeding period. Accordingly, 0.347 mL · kgFFW^"1 (where kgFFW is the fat-free weight of the subject in kg) of the CTL composition or the EXP composition was administered every 10 minutes for 3 hours so that each subject received a total of 6.25 mL · kgFFW^"1 (2.08 mL · kgFFW^"1 · h^"1). The CTL and EXP compositions are described in Table 1 below.

Alpha-Tocopheryl Acetate, Zinc Sulfate, Phosphate, Choline Chloride, Ascorbic Niacinamide, Calcium Pantothenate, Acid, Calcium Carbonate, Potassium Manganese Sulfate, Cupric Sulfate, Vitamin Chloride, L-Carnitine, Carrageenan, Ferrous A Palmitate, Thiamine Chloride Sulfate, dl-Alpha-Tocopheryl Acetate, Zinc Hydrochloride, Pyridoxine Hydrochloride, Sulfate, Gellan Gum, Niacinamide, Riboflavin, Folic Acid, Chromium Chloride, Manganese Sulfate, Calcium Pantothenate, Biotin, Sodium Molybdate, Potassium Cupric Sulfate, Vitamin A Palmitate, Iodide, Sodium Selenate, Phylloquinone, Thiamine Chloride Hydrochloride, Vitamin D₃, and Cyanocobalamin. Pyridoxine Hydrochloride, Riboflavin, Folic

Acid, Chromium Chloride, Biotin, Sodium Molybdate, Sodium Selenate, Potassium Iodide, Phylloquinone, Vitamin D₃, and Cyanocobalamin.

[00120] The timeline depicted in FIG. 1 illustrates the procedure utilized during Visits 2 and 3 for administering the CTL and EXP compositions and taking muscle biopsies. As previously mentioned, CTL or EXP was administered in 18 oral boluses over the 3-hour "Feeding Period." The initial fasted blood sample was drawn only at Visit 2 and was analyzed for total protein, albumin, prealbumin, hemoglobin, hematocrit, RBC, WBC, differentials, platelet count, glucose, BUN, creatinine, sodium, potassium, chloride, calcium, magnesium, phosphorus, uric acid, total cholesterol, triglycerides, SGOT, SGPT, LDH, total bilirubin, thyroid stimulating hormone, vitamin B12 and folic acid, serum 25-OH vitamin D, serum PTH, insulin, sex hormone binding globulin, testosterone, progesterone, 17P-estradiol, and C-reactive protein. During Visits 2 and 3, a first muscle biopsy (fasted state muscle biopsy) was taken prior to administering CTL or EXP and a second muscle biopsy (fed state muscle biopsy) was taken at completion of the 3 -hour feeding period. A portion of each muscle biopsy was homogenized and analyzed for ubiquitination, actin fragmentation, MuRF-1, MAFbx, bax, bcl2, and Fox03.

[00121] Results

[00122] Changes in intramuscular signaling proteins involved in protein degradation pathways were determined. Pulse-feeding of CTL composition did not change the protein level of 14-kDa actin fragment, while pulse-feeding of EXP composition significantly inhibited the level of 14- kDa actin fragment (p=0.017; within group paired t-test). In addition, the data indicate that there is a trend (p=0.085; Wilcoxon rank sum test) of increased inhibition of 14-kDa actin fragment in EXP compared to CTL, as seen in Table 2. The data also show that ubiquitin and MuRF-1 were significantly inhibited after feeding with EXP as compared to CTL, while there was no significant difference in MAFbx levels. Additionally, no significant difference was measured in the levels of bax and bcl2 between CTL and EXP, nor was there any significant alteration in the bax/bcl2 ratio (within group data not shown).

Data (change from pre- to post-feed) are presented as median (25 , 75 percentile) with non-parametric analysis, or as least square mean ± SE with parametric analysis.

[00123] Conclusions

[00124] Consumption of the EXP composition over the 3 -hour period significantly inhibited the protein degradation biomarkers ubiquitin and MuRF-1 compared to the CTL composition, suggesting that the inhibition was through the ubiquitin-proteasome proteolysis pathway. Accordingly, the EXP composition is more effective for preserving lean body mass as compared to the CTL composition.

[00125] The present disclosure should also be understood as including the following as embodiments. 1. A method of attenuating muscle protein degradation in a subject in need thereof, the method comprising: administering an effective amount of a nutritional composition to the subject; wherein the nutritional composition comprises a source of fat, a source of protein, a source of carbohydrates, a source of P-hydroxy-P-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral, and wherein the nutritional composition has from 10-25 grams of protein and from 240-500 kcal per serving; and wherein administration of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby attenuating muscle protein degradation in the subject. 2. The method according to 1, wherein the subject in need thereof is an elderly human. 3. The method according to 1 , wherein the administration of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation within 3 hours of administration. 4. The method according to any one of 1- 3, wherein the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof. 5. The method according to any one of 1-3, wherein the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, and the level of 14-kDa actin fragment decreases from a fasted state to a fed state. 6. The method according to 5, wherein the nutritional composition is administered in multiple feedings. 7. The method according to any one of 1-3, wherein the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is ubiquitin, and the level of ubiquitin decreases from a fasted state to a fed state. 8. The method according to 7, wherein the nutritional composition is administered in multiple feedings. 9. The method according to any one of 1-3, wherein the nutritional composition is administered in a single feeding, the at least one intramuscular signaling protein associated with muscle protein degradation is MuRF-1, and the level of MuRF-1 decreases from a fasted state to a fed state. 10. The method according to 9, wherein the nutritional composition is administered in multiple feedings. 11. The method according to 1, wherein the at least one polyunsaturated fatty acid is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof. 12. The method according to 11, wherein the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid, eicosapentaenoic acid, a-linolenic acid, and combinations thereof, and the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid, arachidonic acid, and combinations thereof. 13. The method according to 1, wherein the at least one monounsaturated fatty acid is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof. 14. The method according to 1, wherein the source of P-hydroxy-P-methylbutyrate is calcium P-hydroxy-P-methylbutyrate monohydrate, and the nutritional composition contains 0.25-10 grams of calcium P-hydroxy-P-methylbutyrate monohydrate per serving. 15. The method according to 1, wherein the nutritional composition further comprises 1-10 grams of fructooligosaccharides per serving. 16. The method according to any one of 1-3 and 11-15, wherein the nutritional composition is a liquid and the serving ranges from 115-300 mL. 17. The method according to any one of 1-3 and 11-15, wherein the nutritional composition is a reconstitutable powder. 18. A method of preserving lean body mass in a subject in need thereof, the method comprising: administering an effective amount of a nutritional composition to the subject; wherein the nutritional composition comprises a source of fat, a source of protein, a source of carbohydrates, a source of P-hydroxy-P-methylbutyrate, at least one polyunsaturated fatty acid, at least one monounsaturated fatty acid, at least one vitamin, and at least one mineral, and wherein the nutritional composition has from 10-25 grams of protein and from 240-500 kcal per serving; and wherein administration of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation, thereby preserving lean body mass in the subject. 19. The method according to 18, wherein the subject in need thereof is an elderly human. 20. The method according to 19, wherein the administration of the effective amount of the nutritional composition results in a decreased level of at least one intramuscular signaling protein associated with muscle protein degradation within 3 hours of administration. 21. The method according to any one of 18-20, wherein the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof. 22. The method according to any one of 18-20, wherein the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, the subject in need thereof has an elevated level of 14-kDa actin fragment, and the subject in need thereof has undergone hip replacement surgery or has suffered a burn injury within the past two years. 23. The method according to 22, wherein the burn injury is a third degree burn injury. 24. The method according to any one of 18-20, wherein the nutritional composition is administered in a single feeding, and the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, and the level of 14-kDa actin fragment decreases from a fasted state to a fed state. 25. The method according to any one of 18-20, wherein the nutritional composition is administered in multiple feedings. 26. The method according to 18, wherein the at least one polyunsaturated fatty acid is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof. 27. The method according to 26, wherein the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid, eicosapentaenoic acid, a-linolenic acid, and combinations thereof, and the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid, arachidonic acid, and combinations thereof. 28. The method according to 18, wherein the at least one monounsaturated fatty acid is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof. 29. The method according to 18, wherein the source of P-hydroxy-P-methylbutyrate is calcium P-hydroxy-P-methylbutyrate monohydrate, and the nutritional composition contains 0.25-10 grams of calcium P-hydroxy-P-methylbutyrate monohydrate per serving. 30. The method according to 18, wherein the nutritional composition further comprises 1-10 grams of fructooligosaccharides per serving. 31. The method according to any one of 18-20 and 26-30, wherein the nutritional composition further comprises between 125-200 IUs of vitamin D per serving. 32. The method according to any one of 18-20 and 26-30, wherein the nutritional composition is a liquid and the serving ranges from 1 15-300 mL. 33. The method according to any one of 18-20 and 26-30, wherein the nutritional composition is a reconstitutable powder.

[00126] To the extent that the term "includes" or "including" is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term "comprising" as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term "or" is employed (e.g., A or B) it is intended to mean "A or B or both." When the applicants intend to indicate "only A or B but not both" then the term "only A or B but not both" will be employed. Thus, use of the term "or" herein is the inclusive, and not the exclusive use. Also, to the extent that the terms "in" or "into" are used in the specification or the claims, it is intended to additionally mean "on" or "onto." Furthermore, to the extent the term "connect" is used in the specification or claims, it is intended to mean not only "directly connected to," but also "indirectly connected to" such as connected through another component or components.

[00127] While the present disclosure illustrates the general inventive concepts by describing various exemplary embodiments thereof, and while the embodiments may be described in considerable detail, the exemplary embodiments are not the intended to restrict or in any way limit the scope of the general inventive concepts, including the appended claims, to such detail. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the general inventive concepts, in their broader aspects, are not limited to the specific details, the representative compositions and methods, or the illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concepts.

Claims

WHAT IS CLAIMED IS:

1. A nutritional composition for use in treating the loss of lean body mass in a subject in need thereof, the nutritional composition comprising: a source of fat; a source of protein; a source of carbohydrates; a source of P-hydroxy-P-methylbutyrate; at least one polyunsaturated fatty acid; at least one monounsaturated fatty acid; at least one vitamin; and at least one mineral; wherein the nutritional composition has from 10 grams to 25 grams of protein and from 240 kcal to 500 kcal per serving; and wherein by administering an effective amount of the nutritional composition to the subject a level of at least one intramuscular signaling protein associated with muscle protein degradation in the subject is decreased.

2. A nutritional composition for use in attenuating muscle protein degradation in a subject in need thereof, the nutritional composition comprising: a source of fat; a source of protein; a source of carbohydrates; a source of P-hydroxy-P-methylbutyrate; at least one polyunsaturated fatty acid; at least one monounsaturated fatty acid; at least one vitamin; and at least one mineral; wherein the nutritional composition has from 10 grams to 25 grams of protein and from 240 kcal to 500 kcal per serving; and wherein by administering an effective amount of the nutritional composition to the subject a level of at least one intramuscular signaling protein associated with muscle protein degradation in the subject is decreased.

3. The nutritional composition for use according to claim 1 or claim 2, wherein the subject in need thereof is an elderly human.

4. The nutritional composition for use according to any one of claims 1-3, wherein by administering an effective amount of the nutritional composition to the subject the level of at least one intramuscular signaling protein associated with muscle protein degradation in the subject is decreased within 3 hours of administration.

5. The nutritional composition for use according to any one of claims 1-4, wherein the at least one intramuscular signaling protein associated with muscle protein degradation is selected from the group consisting of 14-kDa actin fragment, ubiquitin, MuRF-1, and combinations thereof.

6. The nutritional composition for use according to any one of claims 1-5, wherein the nutritional composition is for administering in multiple feedings.

7. The nutritional composition for use according to any one of claims 1-4, wherein the nutritional composition is for administering in a single feeding, the at least one intramuscular signaling protein associated with protein degradation is 14-kDa actin fragment, and the level of 14-kDa actin fragment decreases from a fasted state to a fed state.

8. The nutritional composition for use according to any one of claims 1-4, wherein the at least one intramuscular signaling protein associated with muscle protein degradation is 14-kDa actin fragment, the subject in need thereof has an elevated level of 14-kDa actin fragment, and the subject in need thereof has undergone hip replacement surgery or has suffered a burn injury within the past two years.

9. The nutritional composition for use according to claim 7, wherein the burn injury is a third degree burn injury.

10. The nutritional composition for use according to any one of claims 1-4, wherein the nutritional composition is for administering in a single feeding, the at least one intramuscular signaling protein associated with protein degradation is ubiquitin, and the level of ubiquitin decreases from a fasted state to a fed state.

11. The nutritional composition for use according to any one of claims 1-4, wherein the nutritional composition is for administering in a single feeding, the at least one intramuscular signaling protein associated with protein degradation is MuRF-1, and the level of MuRF-1 decreases from a fasted state to a fed state.

12. The nutritional composition for use according to any of the preceding claims, wherein the at least one polyunsaturated fatty acid is selected from the group consisting of n-3 fatty acids, n-6 fatty acids, and combinations thereof.

13. The nutritional composition for use according to claim 12, wherein the n-3 fatty acids are selected from the group consisting of docosahexaenoic acid, eicosapentaenoic acid, a-linolenic acid, and combinations thereof, and the n-6 fatty acids are selected from the group consisting of linoleic acid, γ-linolenic acid, arachidonic acid, and combinations thereof.

14. The nutritional composition for use according to any one of the preceding claims, wherein the at least one monounsaturated fatty acid is selected from the group consisting of oleic acid, palmitoleic acid, and combinations thereof.

15. The nutritional composition for use according to any one of the preceding claims, wherein the source of P-hydroxy-P-methylbutyrate is calcium P-hydroxy-P-methylbutyrate monohydrate, and the nutritional composition contains 0.25 grams to 10 grams of calcium β- hydroxy-P-methylbutyrate monohydrate per serving.

16. The nutritional composition for use according to any one of the preceding claims, wherein the nutritional composition further comprises 1 gram to 10 grams of

fructooligosaccharides per serving.

17. The nutritional composition for use according to any one of the preceding claims, wherein the nutritional composition further comprises 125 IUs to 200 IUs of vitamin D per serving.

18. The nutritional composition for use according to any one of the preceding claims, wherein the nutritional composition is a liquid and the serving ranges from 115 mL to 300 mL.

19. The nutritional composition for use according to any one of claims 1-17, wherein the nutritional composition is a reconstitutable powder.