Dietary Whey Research Articles

Dietary whey proteins shield murine cecal microbiota from extensive disarray caused by a high-fat diet

High-fat diets are used to induce adverse alterations in the intestinal microbiota, or dysbiosis, generalized inflammation and metabolic stress, which ultimately may lead to obesity. The influence of dietary whey proteins, whether intact or hydrolyzed, has been reported to improve glucose homeostasis and reduce stress. Therefore, the purpose of this work was to test if dietary milk-whey proteins, both in the intact form and hydrolyzed, could have an effect on the compositional changes of the cecal microbiota that can be induced in mice when receiving a high-fat diet in combination with the standard casein. Male C57BL/6 mice were fed a control casein diet (AIN 93-G); high-fat-casein (HFCAS); high-fat-whey protein concentrate (HFWPC) and high-fat whey-protein hydrolysate (HFWPH) for 9weeks. The intestinal microbiota composition was analyzed by 16S-rRNA of the invariant (V1–V3) gene, potentially endotoxemic lipopolysaccharide (LPS) release was determined colorimetrically, and liver fat infiltration assessed by light microscopy. The high-fat diet proved to induce dysbiosis in the animals by inverting the dominance of the phylum Firmicutes over Bacteroidetes, promoted the increase of LPS and resulted in liver fat infiltration. The whey proteins, whether intact or hydrolyzed, resisted the installation of dysbiosis, prevented the surge of circulating LPS and prevented fat infiltration in the liver. It is concluded that dietary whey proteins exert metabolic actions that tend to preserve the normal microbiota profile, while mitigating liver fat deposition in mice consuming a high-fat diet for nine weeks. Such beneficial effects were not seen when casein was the dietary protein. The hydrolyzed whey protein still differed from the normal whey protein by selectively protecting the Bacteroidetes phylum.

Dietary Whey and Casein Differentially Affect Energy Balance, Gut Hormones, Glucose Metabolism, and Taste Preference in Diet-Induced Obese Rats1–3

Background: Dietary whey and casein proteins decrease food intake and body weight and improve glycemic control; however, little is known about the underlying mechanisms.Objective: We determined the effects of dietary whey, casein, and a combination of the 2 on energy balance, hormones, glucose metabolism, and taste preference in rats.Methods: In Expt. 1, Obesity Prone CD (OP-CD) rats were fed a high-fat control diet (33% fat energy) for 8 wk, and then randomly assigned to 4 isocaloric dietary treatments (n = 12/group): the control treatment (CO; 14% protein energy from egg white), the whey treatment (WH; 26% whey + 14% egg white), the casein treatment (CA; 26% casein + 14% egg white), or the whey plus casein treatment (WHCA; 13% whey + 13% casein + 14% egg white) for 28 d. Measurements included food intake, energy expenditure, body composition, metabolic hormones, glucose tolerance and key tissue markers of glucose and energy metabolism. In Expt. 2, naïve OP-CD rats were randomly assigned to 3 groups (n = 8/group). During an 8 d conditioning period, each group received on alternate days either the CO or WH, CO or CA, or CO or WHCA. Subsequently, preferences for the test diets were assessed on 2 consecutive days with food intake measurements at regular intervals.Results: In Expt. 1, food intake was decreased by 17–37% for the first 14 d in the WH and CA rats, and by 18–34% only for the first 4 d in the WHCA compared with the CO rats. Fat mass decreased by 21–28% for the WH rats and 17–33% for the CA rats from day 14 onward, but by 30% only on day 28 in WHCA rats, relative to CO rats. Thus, food intake, body weight, and fat mass decreased more rapidly in WH and CA rats than in WHCA rats. Energy expenditure in WH rats decreased for the first 4 d compared with CA and WHCA rats, and for the first 7 d compared with the CO rats. Circulating leptin, glucose-dependent insulinotropic polypeptide, interleukin 6, and glucose concentrations were lower in WH, CA, and WHCA rats than in CO rats. Plasma glucagon-like peptide 1 concentrations were greater in WH than in CA or WHCA rats. The improvements in glucose tolerance were greater in WH than in WHCA rats. The plasma membrane glucose transporter 4 (GLUT4)–to-total GLUT4 ratio in skeletal muscle was greater in CA and WHCA rats than in CO rats; other markers of glucose and energy metabolism in the adipose and cardiac tissues did not differ. In Expt. 2, during 4 conditioning trials, daily food intake was decreased in WH, CA, and WHCA rats by 26–37%, 30–43%, and 23–33%, respectively, compared with CO rats. Preferences for WH and CA rats were 45% and 31% lower, respectively, than those for CO rats, but that for WHCA rats did not differ.Conclusion: Together, these data demonstrate that in obese rats, whey, casein, and their combination improve energy balance through differential effects on food intake, taste preference, energy expenditure, glucose tolerance, and gut hormone secretion.

The efects of whey protein and resistant starch on body weight

Background: Obesity is widely recognized as one of the most critical health threats to families and children across the country. Obesity is a very serious health problem for people in Louisiana and especially in African Americans Children with 40.5% in the State classified as either overweight or obese as compared to 41.2% nationally. African American women have the highest rates of being overweight or obese (79.8%) compared to non-Hispanic whites (57.9%). In 2007, African Americans were 1.4 times as likely to be obese as whites. Therefore this study was designed to test the impact of dietary whey protein (WP) and resistant starch (RS) shakes/smoothies on reduction of body fat via increased satiety and increased energy expenditure in African Americans. Methods: Twenty eight African American males and females, age 21-43 years old were randomly divided into two groups. For a period of 24-weeks, the treatment group consumed WP and RS shakes/smoothies for breakfast and received nutrition education. For the same period, the control group consumed the same shake/smoothies but with starch powder and received nutrition education. The data was analyzed using SAS version 9.3. Results: At the end of the 24 week study, the treatment group lost a mean body weight of approximately 7 kg (P ≤ 0.008) that was significantly different from the control group (P ≤ 0.209). In addition, the treatment group exhibited a significant decrease of ~6 cm in waist circumference (P ≤ 0.023). There was no significant effect on mean blood pressure in treatment and control group.Conclusion: The findings from this study suggest that a combination of WP and RS in the form of shake/smoothie consumed for breakfast along with a nutrition education component may be an effective method in decreasing body weight, improving waist circumferences and cumulative food intake in African American males and females. Key Words: Whey Protein, Resistant Starch, Obesity, Breakfast shakes, Nutrition education

Abstracts

Muscle unloading, as encountered during space flight and disuse, induces skeletal muscle atrophy and weakness, switch of fibre types and loss of capillaries. Less attention has been given to disuse-induced changes in oxidative capacity, which may affect endurance. Here we investigated the impact of 21 days, 60 head-down bed rest on muscle fibre size, fibre type composition, capillarisation and muscle oxidative capacity and the efficacy of milk-based proteins (whey protein) to counteract disuse-induced muscle changes. Muscle biopsies were taken from the soleus (SOL) and vastus lateralis (VL)muscles before and after bed rest from10 healthy men (aged 31 ± 6 years). Subjects were assigned to two groups and studied twice in two follow-up campaigns, in once receiving whey protein and once receiving a standardized isocaloric diet. Fibre types and capillaries were identified by immunohistochemical staining of muscle section with anti-myosin type1 and lectin. Analysis was done with the method of capillary domains.Oxidative capacity of individual fibres was determined as the optical density (OD) at 660 nm of succinate dehydrogenase (SDH) stained histological sections. The fibre cross-sectional area times the SDH-OD of that fibre (integrated SDH) was index of maximal oxygen consumption of that fibre(VO2max). Statistical analysis was done by repeated measures ANOVA. Bed rest did not induce significant changes infibre type composition, fibre size or capillarisation, but decreased SDH activity (p\0.001) and fibre VO2max (p\0.01) in both muscles. Whey protein partially counteracted the decrease in oxidative capacity. Our results suggest that decrements in oxidative capacity may be an early hallmark of disuse-induced muscle adaptations and occurs even in the absence of significant fibre atrophy and capillary rarefaction. The Whey diet attenuated these effects and may thus be an effective supplement to sustain oxidative capacity during space flight and long-term bed rest.

Dietary whey protein influences plasma satiety-related hormones and plasma amino acids in normal-weight adult women

A distinct suppressive effect of a whey protein (including glycomacropeptide)-enriched preload drink on subsequent food intake in comparison with a maltodextrin carbohydrate-enriched preload was demonstrated in an earlier companion study with the same female subjects; however, the potential mediators underlying the effect are unclear. The objective of this study was to investigate how the ingestion of a whey protein-enriched preload beverage affected postprandial plasma concentrations of several satiety-related gastrointestinal hormones and metabolites in comparison with a maltodextrin carbohydrate-enriched preload. Eighteen normal-weight women were studied in a single-blind, randomized block design. Blood samples were collected at various time intervals for 120 min after consumption of a test drink (300 ml, ~1300 kJ) enriched (45 g) with either maltodextrin carbohydrate or whey protein containing naturally present glycomacropeptide. Plasma-active ghrelin concentrations decreased after both maltodextrin carbohydrate- and whey protein-enriched test drinks (P<0.05). The whey protein-enriched beverage led to increased plasma concentrations of cholecystokinin (CCK) at 60 and 75 min (P<0.05), glucagon-like peptide-1 (GLP-1) at 90 min (P<0.001), peptide tyrosine-tyrosine (PYY) at 90 and 120 min (P<0.01) and pancreatic polypeptide (PP) from 15 to 120 min (P<0.05) compared with maltodextrin carbohydrate. Total amino acid, urea and ammonia plasma concentrations were also higher after whey protein compared with maltodextrin carbohydrate ingestion (P<0.01). Increased plasma concentrations of some gastrointestinal hormones related to satiety, particularly PP, and of amino acids and their metabolites, may have acted either singly or together to mediate the observed satiety response to whey protein.

Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weanling pigs challenged withEscherichia coliF4

Sugiharto, S., Jensen, B. B., Hedemann, M. S. and Lauridsen, C. 2014. Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weanling pigs challenged with Escherichia coli F4. Can. J. Anim. Sci. 94: 479–491. The differences in amino acid composition in casein and whey have been thought to exert different immunomodulatory and metabolic effects. The objective of this study was to compare the effects of casein and whey on performance, immune responses and plasma metabolomic profile of weanling pigs challenged with Escherichia coli F4. Two factorial experiments involving 24 weanling pigs were conducted. Diets containing casein or whey, and challenge with E. coli O149:F4 or not, were the two factors. Blood was sampled on the day before challenge and 4 and 7 d postchallenge. For measurement of mucosal immune responses and intestinal dimensions, samples were collected from the small intestine (SI) immediately after killing at 7 d postchallenge. Feeding the whey diet de...

Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weanling pigs challenged with E. coli F4

Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weanling pigs challenged with E. coli F4

Fat and whey supplementation influence milk composition, backfat loss, and reproductive performance in lactating sows

This study investigates the effects of microencapsulated fat (FAT) and whey protein (WHEY) supplementation on the milk composition, backfat loss, and reproductive performance in lactating sows. A total of 144 sows were divided according to their backfat thickness at farrowing into three groups, i.e., low (12.0-16.5mm, n = 33), moderate (17.0-21.5mm, n = 78), and high (22.0-24.5mm, n = 33). The lactation diet was divided into three types, i.e., a control diet (CONTROL, n = 50), a diet supplemented with FAT (n = 48), and a diet supplemented with WHEY (n = 50). Pooled milk samples were collected at the second and third week of lactation. On average, the sows lost backfat 23.5% during lactation. The backfat loss during lactation was 24.5, 22.7, and 22.8% in sows fed with CONTROL, FAT, and WHEY diets, respectively (P > 0.05). Supplementation of FAT increased the percentage of fat in the sow's milk compared to the CONTROL (9.1 and 8.4%, P = 0.022). For sows with low backfat, FAT and WHEY supplementation increased the average daily gain of piglets compared to the CONTROL (244, 236, and 205g/days, respectively, P < 0.05). For sows with high backfat, the sows receiving the CONTROL diet had a higher total piglet mortality than those that received FAT or WHEY (28.1, 14.1, and 13.0%, respectively, P < 0.05). It could be concluded that supplementation of FAT in the diet of sow during lactation significantly enhanced the fat content in the sow's milk, improved the piglet's daily weight gain, and reduced piglet mortality.

The effects of dietary whey protein concentrate level on performance, selected intestinal tract and blood parameters, and thiobarbituric acid reactive substances in the liver and breast meat of broiler chickens

The aim of this study was to investigate the effect of two levels of whey protein concentrate (WPC, 80.35% protein, 5.86% lactose) added to diets and duration of these treatments on growth and slaughter value, haematological parameters involved in immune processes, oxidative status of liver and breast muscle, and selected indices of gut function of broilers. A total of 560 Ross 308 broilers were randomly allocated into 7 groups with 10 replicates of 8 chickens per replicate. The experiment lasted 42 days and was divided into 3 successive feeding phases. The control group was fed basal diets consisted of maize, wheat and soyabean meal (C group). The other 6 groups received, for 7, 21 and 42 days basal diets with 8 or 32 g · kg -1 WPC added at the expense of soyabean meal (WL and WH groups, respectively). On day 42 group WH had a higher lymphocyte percentage (P < 0.05) compared to the control. The long-term (42 days) feeding with higher level of WPC significantly decreased the heterophile/lymphocyte ratio ( P < 0.05 vs C). The number of erythrocytes on day 42 and the whole blood glucose on day 21 were significantly increased in WH birds than in controls. The concentration of serum total protein on both WPC levels was greater (P < 0.05) on day 21 compared with the C group. The reduction (P < 0.05) in liver thiobarbituric acid reactive substances (TBARS) and a tendency towards lower TBARS level in breast meat were observed in birds WH when fed for 42 days. Only higher dietary WPC amount provided for 42 days reduced the caecal and small intestinal pH values (P < 0.05 vs C). The ileal digestibility of crude protein was higher (P < 0.01) in birds fed with 32 g WPC during the first 21 days of life, compared to the C and WL treatments. The factorial ANOVA showed that on days 7, 21 and 42 the final body weight gain (BGW) and feed conversion ratio in broilers WL and WH were significantly better than in the C ones. Assessment of orthogonal contrasts revealed significantly higher ( P < 0.05) final BWG in the WH broilers, compared to the WL dietary treatment; such effect was not observed in earlier feeding stages. Generally, carcass yield on both WPC dietary levels, and breast muscle percentage on WH treatment, were higher (P < 0.01 and P < 0.05, respectively) compare to the C group. In conclusion, WPC added to a conventional diets for growing chickens exerts a growth-promoting action and at a dose of 32 g · kg -1 may induce desirable changes in bird's health and the

Dietary whey protein stimulates mitochondrial activity and decreases oxidative stress in mouse female brain

In humans and experimental animals, protein-enriched diets are beneficial for weight management, muscle development, managing early stage insulin resistance and overall health. Previous studies have shown that in mice consuming a high fat diet, whey protein isolate (WPI) reduced hepatosteatosis and insulin resistance due in part to an increase in basal metabolic rate. In the current study, we examined the ability of WPI to increase energy metabolism in mouse brain. Female C57BL/6J mice were fed a normal AIN-93M diet for 12 weeks, with (WPI group) or without (Control group) 100g WPI/L drinking water. In WPI mice compared to controls, the oxidative stress biomarkers malondialdehyde and 4-hydroxyalkenals were 40% lower in brain homogenates, and the production of hydrogen peroxide and superoxide were 25–35% less in brain mitochondria. Brain mitochondria from WPI mice remained coupled, and exhibited higher rates of respiration with proportionately greater levels of cytochromes a+a3 and c+c1. These results suggested that WPI treatment increased the number or improved the function of brain mitochondria. qRT-PCR revealed that the gene encoding a master regulator of mitochondrial activity and biogenesis, Pgc-1alpha (peroxisome proliferator-activated receptor-gamma coactivator-1alpha) was elevated 2.2-fold, as were the PGC-1alpha downstream genes, Tfam (mitochondrial transcription factor A), Gabpa/Nrf-2a (GA-binding protein alpha/nuclear respiratory factor-2a), and Cox-6a1 (cytochrome oxidase-6a1). Each of these genes had twice the levels of transcript in brain tissue from WPI mice, relative to controls. There was no change in the expression of the housekeeping gene B2mg (beta-2 microglobulin). We conclude that dietary whey protein decreases oxidative stress and increases mitochondrial activity in mouse brain. Dietary supplementation with WPI may be a useful clinical intervention to treat conditions associated with oxidative stress or diminished mitochondrial activity in the brain.

The effects of native whey and α-lactalbumin on the social and individual behaviour of C57BL/6J mice

Milk proteins are the main components of everyday feeding and demonstrate a promising potential to change the mental condition. However, the effects of milk proteins after prolonged use remain poorly understood. The aim of the present study was to compare the effects of two whey proteins (alpha-lactalbumin (alpha-lac) and native whey) with casein on social and individual behaviour in mice. During a 30 d-long dietary intervention, male C57BL/6J mice had ad libitum access to an experimental diet containing 17% (w/w) of one of three protein sources: a-lac, native whey or casein. Mice had voluntary access to a running wheel. Social behaviour (group and resident-intruder activity) was tested at baseline and at the end of the intervention. Half of each dietary group was then withdrawn from the diet and running wheel for 7 d, and social activity and individual behaviour tests (open field, elevated-plus maze, light–dark box and forced swimming) were performed, to evaluate anxiety and depression-like status. The study shows that the long-term ingestion of whey proteins may modulate behaviour when compared with casein. Diet enriched with a-lac exhibited anxiolytic and antidepressive activities while the whey diet improved sociability. The differences between the diet groups were pronounced under the running wheel and the withdrawal of the experimental diet, suggesting that the beneficial effects of the milk proteins are clearer in stressful situations. Diet-induced behavioural changes remained visible for a week after feeding, which suggests that the proteins of the milk whey fraction have prolonged efficacy on the mental state of mice.

Short Communication: Effects of feeding wheat bran and condensed liquid whey in diets of growing cattle

Friedt, A. D. and McKinnon, J. J. 2012. Short Communication: Effects of feeding wheat bran and condensed liquid whey in diets of growing cattle. Can. J. Anim. Sci. 92: 501–504. Wheat bran (WB) derived from abrasion milling prior to ethanol production was evaluated in backgrounding diets for steer calves alone or in combination with condensed liquid whey (CLW) as a partial replacement for barley grain. There was no effect of CLW on any performance parameter, nor was any WB×CLW interaction detected. Average daily gain was not affected (P&gt;0.05) by WB inclusion; however, dry matter intake of cattle fed WB was higher (P&lt;0.01) than that of cattle fed the barley-based diet. Gain:feed and estimated diet NEg content were decreased (P&lt;0.01) by WB inclusion. Ultrasound carcass traits were not (P&gt;0.05) affected by treatment. These results indicate that WB can replace barley grain at levels up to 28% of the diet DM without impacting ADG or composition of gain in growing calves. However, calculated NEg of WB-based diets is lower than that of barley-based diets, thus calves must consume more feed DM to maintain similar gains.

Dietary Whey Protein Hydrolysates Increase Skeletal Muscle Glycogen Levels via Activation of Glycogen Synthase in Mice

Previously, we have shown that consuming carbohydrate plus whey protein hydrolysates (WPHs) replenished muscle glycogen after exercise more effectively than consuming intact whey protein or branched-chain amino acids (BCAAs). The mechanism leading to superior glycogen replenishment after consuming WPH is unclear. In this 5 week intervention, ddY mice were fed experimental diets containing WPH, a mixture of whey amino acids (WAAs), or casein (control). After the intervention, gastrocnemius muscle glycogen levels were significantly higher in the WPH group (4.35 mg/g) than in the WAA (3.15 mg/g) or control (2.51 mg/g) groups. In addition, total glycogen synthase (GS) protein levels were significantly higher in the WPH group (153%) than in the WAA (89.2%) or control groups, and phosphorylated GS levels were significantly decreased in the WPH group (51.4%). These results indicate that dietary WPH may increase the muscle glycogen content through increased GS activity.

Dietary whey protein lessens several risk factors for metabolic diseases: a review

Obesity and type 2 diabetes mellitus (DM) have grown in prevalence around the world, and recently, related diseases have been considered epidemic. Given the high cost of treatment of obesity/DM-associated diseases, strategies such as dietary manipulation have been widely studied; among them, the whey protein diet has reached popularity because it has been suggested as a strategy for the prevention and treatment of obesity and DM in both humans and animals. Among its main actions, the following activities stand out: reduction of serum glucose in healthy individuals, impaired glucose tolerance in DM and obese patients; reduction in body weight; maintenance of muscle mass; increases in the release of anorectic hormones such as cholecystokinin, leptin, and glucagon like-peptide 1 (GLP-1); and a decrease in the orexigenic hormone ghrelin. Furthermore, studies have shown that whey protein can also lead to reductions in blood pressure, inflammation, and oxidative stress.

Contributions to the understanding of the anabolic properties of different dietary proteins

Contributions to the understanding of the anabolic properties of different dietary proteins

Whey Protein Versus Whey Protein Hydrolyzate for the Protection of Azoxymethane and Dextran Sodium Sulfate Induced Colonic Tumors in Rats

Recent studies have shown that whey protein has many useful effects including its anti-cancer effect. In this study we have compared the protective effect of dietary whey protein with whey protein hydrolyzate against azoxymethane and dextran sodium sulfate induced colon cancer in rats. We used a rat model of the colon cancer induced by administration of azoxymethane followed by repeated dextran sodium sulfate ingestion which causes multiple tumor development. Colon tissues were analyzed histologically in addition to biochemical analyses performed by measuring lipid peroxidation, protein oxidation and glutathione levels in both of colon and liver tissues of rats after sacrification. Macroscopic and microscopic tumors were identified in all groups that received azoxymethane followed by repeated dextran sodium sulfate. Group fed with whey protein hydrolyzate showed significantly less macroscopic and microscopic tumor development compared with group fed with whey protein. The protocol applied to generate an appropriate model of colon cancer was successful. Whey protein hydrolyzate was found to be more effective in preventing colon tumor development compared with whey protein.

Immunoenhancing property of dietary un-denatured whey protein derived from three camel breeds in mice

Data have demonstrated that whey protein (WP) enhances the immune system. The aim of this study was to investigate and compare the effects of WP from three camel breeds on oxidative stress, blood lipid profile and the cytokine levels. Seventy five male mice were randomly split into five groups. The first served as a control group. The second, the third and the fourth groups were orally administrated the WP from Majaheim, Maghateer and Soffer camel breeds, respectively, at a dose of 100 mg/kg mouse body weight. The fifth group was supplemented with bovine serum albumin (BSA). Results showed similar electrophoretic patterns of the three whey proteins. WP was found to significantly inhibit the hydroperoxide and the Reactive Oxygen Species (ROS) in leukocytes, liver and skin as well as the blood cholesterol level in a time dependent manner. A significant enhancement of glutathione was revealed in WP groups. Furthermore, WP was found to significantly elevate the IL-2 with a significant time dependent enhance of IL-8. On contrast, a significant lowering effect of whey proteins on the pro-inflammatory cytokines, IL-1α, IL-1β, IL-6 and IL-10 was detected. Moreover, a mitogenic activity of WP was observed on the lymphocytes. Non-significant changes were observed in AST, ALT, creatinine and glucose level. These findings suggest that WP significantly improved the levels of the oxidative markers and the immune functions without any difference in the bioactivities of the three studied whey proteins.

Dietary Whey Protein Decreases Food Intake and Body Fat in Rats

We investigated the effects of dietary whey protein on food intake, body fat, and body weight gain in rats. Adult (11-12 week) male Sprague-Dawley rats were divided into three dietary treatment groups for a 10-week study: control. Whey protein (HP-W), or high-protein content control (HP-S). Albumin was used as the basic protein source for all three diets. HP-W and HP-S diets contained an additional 24% (wt/wt) whey or isoflavone-free soy protein, respectively. Food intake, body weight, body fat, respiratory quotient (RQ), plasma cholecystokinin (CCK), glucagon like peptide-1 (GLP-1), peptide YY (PYY), and leptin were measured during and/or at the end of the study. The results showed that body fat and body weight gain were lower (P < 0.05) at the end of study in rats fed HP-W or HP-S vs. control diet. The cumulative food intake measured over the 10-week study period was lower in the HP-W vs. control and HP-S groups (P < 0.01). Further, HP-W fed rats exhibited lower N(2) free RQ values than did control and HP-S groups (P < 0.01). Plasma concentrations of total GLP-1 were higher in HP-W and HP-S vs. control group (P < 0.05), whereas plasma CCK, PYY, and leptin did not differ among the three groups. In conclusion, although dietary HP-W and HP-S each decrease body fat accumulation and body weight gain, the mechanism(s) involved appear to be different. HP-S fed rats exhibit increased fat oxidation, whereas HP-W fed rats show decreased food intake and increased fat oxidation, which may contribute to the effects of whey protein on body fat.

Dietary Whey Protein Lowers the Risk for Metabolic Disease in Mice Fed a High-Fat Diet ,

Consuming a high-fat (HF) diet produces excessive weight gain, adiposity, and metabolic complications associated with risk for developing type 2 diabetes and fatty liver disease. This study evaluated the influence of whey protein isolate (WPI) on systemic energy balance and metabolic changes in mice fed a HF diet. Female C57BL/6J mice received for 11 wk a HF diet, with or without 100 g WPI/L drinking water. Energy consumption and glucose and lipid metabolism were examined. WPI mice had lower rates of body weight gain and percent body fat and greater lean body mass, although energy consumption was unchanged. These results were consistent with WPI mice having higher basal metabolic rates, respiratory quotients, and hepatic mitochondrial respiration. Health implications for WPI were reflected in early biomarkers for fatty liver disease and type 2 diabetes. Livers from WPI mice had significantly fewer hepatic lipid droplet numbers and less deposition of nonpolar lipids. Furthermore, WPI improved glucose tolerance and insulin sensitivity. We conclude that in mice receiving a HF diet, consumption of WPI results in higher basal metabolic rates and altered metabolism of dietary lipids. Because WPI mice had less hepatosteatosis and insulin resistance, WPI dietary supplements may be effective in slowing the development of fatty liver disease and type 2 diabetes.

Dietary whey hydrolysate with exercise alters the plasma protein profile: A comprehensive protein analysis

Objective It has been shown that dietary whey protein accelerates glucose uptake by altering glycoregulatory enzyme activity in skeletal muscle. In the present study, we investigated the effect of dietary whey protein on endurance and glycogen resynthesis and attempted to identify plasma proteins that reflected the physical condition by a comprehensive proteomics approach. Methods Male c57BL/6 mice were divided into four groups: sedentary, sedentary with whey protein hydrolysate, exercise, and exercise with whey protein hydrolysate. The mice in the exercise groups performed treadmill running exercise five times per week for 4 wk. Protein profiling of plasma sample obtained from individuals was performed, as were measurements of endurance performance and the glycogen content of gastrocnemius muscle. Results After the training period, the endurance of mice fed the whey diet was improved compared with that of mice fed the control diet. Muscle glycogen content was significantly increased after 4 wk of exercise, and intake of whey protein led to a further increase in glycogen. Apolipoproteins A-II and C-I and β 2-glycoprotein-1 were found to be altered by training combined with the intake of whey protein, without significant changes induced by exercise or whey protein alone. Conclusion Results of the present study suggest that these three proteins may be potential biomarkers of improved endurance and glycogen resynthesis and part of the mechanism that mediates the benefits of whey protein.