Ingestion Of Whey Research Articles

Differential effects of milk proteins on amino acid digestibility, post-prandial nitrogen utilization and intestinal peptide profiles in rats

ObjectiveThe aim of this study was to analyze the protein digestibility and postprandial metabolism in rats of milk protein matrices obtained by different industrial processes. Material and methodsThe study was conducted on Wistar rats that consumed a meal containing different 15N-labeled milk proteins. Four milk matrices were tested: native micellar caseins (C1), caseins low in calcium (C2 low Ca2+), a matrix containing a ratio 63:37 of caseins and whey proteins (CW2) and whey proteins alone (W). Blood and urine were collected during the postprandial period and rats were euthanized 6 h after meal intake to collect digestive contents and organs. ResultsOrocaecal digestibility values of amino acids ranged between 96.0 ± 0.2% and 96.6 ± 0.4% for C1-, C2 low Ca2+- and W-matrices, while this value was significantly lower for CW2 matrix (92.4 ± 0.5%). More dietary nitrogen was sequestered in the splanchnic area (intestinal mucosa and liver) as well as in plasma proteins after ingestion of W matrix, especially compared to the C1- and C2 low Ca2+-matrices. Peptidomic analysis showed that more milk protein-derived peptides were identified in the caecum of rats after the ingestion of the matrices containing caseins compared to W matrix. ConclusionWe found that demineralization of micellar caseins did not modify its digestibility and postprandial metabolism. The low digestibility of the modified casein-to-whey ratio matrix may be ascribed to a lower accessibility of the protein to digestive enzymes due to changes in the protein structure, while the higher nitrogen splanchnic retention after ingestion of whey was probably due to the fast assimilation of its protein content. Finally, our results showed that industrial processes that modify the structure and/or composition of milk proteins influence protein digestion and utilization.

Effects of pre-meal whey protein consumption on acute food intake and energy balance over a 48-hour period

• Whey protein (20 g) reduced energy intake in both HW (193.4 kcal, 15.9 %) and OV/OB (215.81 kcal, 17.8 %) when consumed 20 min prior to mealtime, compared to placebo. • Energy deficits induced in an ad libitum test meal did not upregulate compensatory behaviours over the following 48 h. • A slowed eating rate may influence food intake following premeal whey ingestion. The effects of pre-meal whey protein consumption on acute food intake and subsequent energy balance measured over 48-h was investigated in males of healthy-weight (HW) or living with overweight and obesity (OV/OB). On two separate trial days, following a controlled breakfast (09:00) and lunch (13:00), 12 HW and 12 OV/OB males consumed either whey protein (20 g) or flavoured water beverages (16:40), and ad libitum test meal (17:00). A controlled 48-h assessment of energy intake and expenditure was used to determine any compensatory behaviour. Test meal energy intake reduced 15.9 % in HW (P = 0.003), and 17.8 % in OV/OB (P = 0.005) following whey protein, compared to placebo. We report no between-group differences and no changes in compensatory behaviour. A small dose of whey protein reduces energy intake at the next meal, without upregulating compensatory behaviours in both HW and OV/OB males. However, chronic effects on body composition and weight loss remain to be elucidated.

Acute Salt Toxicity Caused by Whey Ingestion in Mixed-breed 6-months old Puppy: A case study

This case report aims to emphasize the acute management of a dog with suspected salt intoxication, which consists of a treatment protocol with hematological and Modified Glasgow Coma Scale (MGCS) changes and electrocardiographic (ECG) evaluation. A 6-month-old male mixed-breed dog was admitted to the emergency clinic with complaints of weakness, hypersalivation, vomiting, diarrhea and gait disturbance. It was learned from the owner that the dog was fed on whey for the first time on the morning of the admission day. Salt toxication was suspected based on history and clinical symptoms. The diagnosis was confirmed by laboratory analysis (pH: 7.185, Na: 178 mmol./L, Cl: 155 mmol./L, K: 8.3 mmol./L, HCO3: 16.1 mmol./L, BE: -8.8 mmol./L, BUN: 105.7 mg/dl, creatinine: 5.4 mg/dl, AST: 513 U/L, amylase: 2324 U/L, LDH: 794 U/L, calcium: 11.8 mg/dl, phosphorus: 13.9 mg/dl, cholesterol: 515 mg/dl, magnesium: 3.6 mg/dl, GGT: 62 U/L CPK: 450 U/L and CK-MB: 324.5 U/L), ECG (sinus tachycardia (180 bpm) and mild ST depression) and MGCS evaluation (pre-treatment score; 7, grave). A treatment protocol including fluid therapy, antiemetic, diuretic, anticonvulsant, beta-blocker to prevent sodium retention and oxygen therapy was administrated to the dog during the hospitalization period. It was observed that the clinical findings and MGCS score improved and some blood parameters returned to their reference range on Day 2. Since the dog died on Day 3 after the hospitalization period, which was terminated at the owner's request, it was concluded that an adequate hospitalization period is important. The presented treatment protocol with MGCS evaluation in salt toxicity was successful enough only in acute management.

Effects of whey protein on skeletal muscle microvascular and mitochondrial plasticity following 10weeks of exercise training in men with type2 diabetes.

Skeletal muscle microvascular dysfunction and mitochondrial rarefaction feature in type2 diabetes mellitus (T2DM) linked to low tissue glucose disposal rate (GDR). Exercise training and milk protein supplementation independently promote microvascular and metabolic plasticity in muscle associated with improved nutrient delivery, but combined effects are unknown. In a randomised-controlled trial, 24 men (55.6 y, SD5.7) with T2DM ingested whey protein drinks (protein/carbohydrate/fat: 20/10/3 g; WHEY) or placebo (carbohydrate/fat: 30/3 g; CON) before/after 45 mixed-mode intense exercise sessions over 10 weeks, to study effects on insulin-stimulated (hyperinsulinemic clamp) skeletal-muscle microvascular blood flow (mBF) and perfusion (near-infrared spectroscopy), and histological, genetic, and biochemical markers (biopsy) of microvascular and mitochondrial plasticity. WHEY enhanced insulin-stimulated perfusion (WHEY-CON 5.6%; 90% CI -0.1, 11.3), while mBF was not altered (3.5%; -17.5, 24.5); perfusion, but not mBF, associated (regression) with increased GDR. Exercise training increased mitochondrial (range of means: 40%-90%) and lipid density (20%-30%), enzyme activity (20%-70%), capillary:fibre ratio (∼25%), and lowered systolic (∼4%) and diastolic (4%-5%) blood pressure, but without WHEY effects. WHEY dampened PGC1α -2.9% (90% compatibility interval: -5.7, -0.2) and NOS3 -6.4% (-1.4, -0.2) expression, but other messenger RNA (mRNA) were unclear. Skeletal muscle microvascular and mitochondrial exercise adaptations were not accentuated by whey protein ingestion in men with T2DM. ANZCTR Registration Number: ACTRN12614001197628. Novelty: Chronic whey ingestion in T2DM with exercise altered expression of several mitochondrial and angiogenic mRNA. Whey added no additional benefit to muscle microvascular or mitochondrial adaptations to exercise. Insulin-stimulated perfusion increased with whey but was without impact on glucose disposal.

The Effects of Whey vs. Pea Protein on Physical Adaptations Following 8-Weeks of High-Intensity Functional Training (HIFT): A Pilot Study.

This study examined the effects of whey and pea protein supplementation on physiological adaptations following 8-weeks of high-intensity functional training (HIFT). Fifteen HIFT men (n = 8; 38.6 ± 12.7 y, 1.8 ± 0.1 m, 87.7 ± 15.8 kg) and women (n = 7; 38.9 ± 10.9 y, 1.7 ± 0.10 m, 73.3 ± 10.5 kg) participated in this study. Participants completed an 8-week HIFT program consisting of 4 training sessions per week. Participants consumed 24 g of either whey (n = 8) or pea (n = 7) protein before and after exercise on training days, and in-between meals on non-training days. Before and after training, participants underwent ultrasonography muscle thickness measurement, bioelectrical impedance analysis (BIA), two benchmark WODs (workout of the day), 1-Repetition Maximum (1RM) squat and deadlift testing, and Isometric Mid-thigh Pull (IMTP) performance. Separate analyses of covariance (ANCOVA) were performed on all measures collected at POST. Both groups experienced increased strength for 1RM back squat (p = 0.006) and deadlift (p = 0.008). No training effect (p > 0.05) was found for body composition, muscle thickness, IMTP peak force, IMTP rate of force development, or performance in either WOD. Using PRE values as the covariate, there were no group differences for any measured variable. We conclude that ingestion of whey and pea protein produce similar outcomes in measurements of body composition, muscle thickness, force production, WOD performance and strength following 8-weeks of HIFT.

Resistance Exercise and Low Dose Protein Ingestion Augments Anabolic Signaling Mechanisms In Older Women

Resistance exercise enhances skeletal muscle anabolic signaling responses to the ingestion of sub-optimal amounts of protein in young men. However, the effectiveness of resistance exercise to potentiate the phosphorylation of the mechanistic target of rapamycin (mTORC1) to the ingestion of minimal amount of protein in aging women has not been well characterized. PURPOSE: We compared the phosphorylated-state ofmTORC1 before and after ingestion of ~14 g whey protein or water at rest and after resistance exercise in middle-aged and older women. METHODS: 10 women (59±2 y; BMI: 25±1 kg/m2; LBM: 46±2 kg) performed a bout of unilateral leg extension exercise (3 sets × 12 repetitions at 60% estimated 1RM) prior to ingesting whey protein (0.3g/kg LBM; WHEY, n=5) or water (WATER n=5). Blood and skeletal muscle biopsies were used to measure plasma amino acids and insulin concentrations and phosphorylation of mTORC1 at Ser2448 at 2 and 4 h of the postprandial phase in both exercise (EX) and non-exercised (CON) legs. RESULTS: Plasma branched chain amino acid concentrations were increased from basal (2.5-fold) in WHEY (P<0.05), but not in WATER condition (P>0.05). Plasma insulin concentrations increased after WHEY (2.3±0.8 fold change from basal, P=0.02), but not after WATER ingestion (1.0 ± 0.1 fold-change, P=0.45). WHEY ingestion increased mTORC1 phosphorylation at 2 h (3.4±0.6 and 1.7±0.3 fold-change in EX and CON, respectively P<0.05). There were no changes in mTORC1 phosphorylation after WATER ingestion at any time point (P>0.05). CONCLUSION: Our data demonstrated that consuming a minimal amount of protein immediately after resistance exercise resulted in a greater, but transient, phosphorylation of anabolic signaling mechanisms involved in protein translation over that induced by feeding or resistance exercise alone.

Native whey protein with high levels of leucine results in similar post-exercise muscular anabolic responses as regular whey protein: a randomized controlled trial

BackgroundProtein intake is essential to maximally stimulate muscle protein synthesis, and the amino acid leucine seems to possess a superior effect on muscle protein synthesis compared to other amino acids. Native whey has higher leucine content and thus a potentially greater anabolic effect on muscle than regular whey (WPC-80). This study compared the acute anabolic effects of ingesting 2 × 20 g of native whey protein, WPC-80 or milk protein after a resistance exercise session.MethodsA total of 24 young resistance trained men and women took part in this double blind, randomized, partial crossover, controlled study. Participants received either WPC-80 and native whey (n = 10), in a crossover design, or milk (n = 12). Supplements were ingested immediately (20 g) and two hours after (20 g) a bout of heavy-load lower body resistance exercise. Blood samples and muscle biopsies were collected to measure plasma concentrations of amino acids by gas-chromatography mass spectrometry, muscle phosphorylation of p70S6K, 4E–BP1 and eEF-2 by immunoblotting, and mixed muscle protein synthesis by use of [2H5]phenylalanine-infusion, gas-chromatography mass spectrometry and isotope-ratio mass spectrometry. Being the main comparison, differences between native whey and WPC-80 were analysed by a one-way ANOVA and comparisons between the whey supplements and milk were analysed by a two-way ANOVA.ResultsNative whey increased blood leucine concentrations more than WPC-80 and milk (P < 0.05). Native whey ingestion induced a greater phosphorylation of p70S6K than milk 180 min after exercise (P = 0.03). Muscle protein synthesis rates increased 1–3 h hours after exercise with WPC-80 (0.119%), and 1–5 h after exercise with native whey (0.112%). Muscle protein synthesis rates were higher 1–5 h after exercise with native whey than with milk (0.112% vs. 0.064, P = 0.023).ConclusionsDespite higher-magnitude increases in blood leucine concentrations with native whey, it was not superior to WPC-80 concerning effect on muscle protein synthesis and phosphorylation of p70S6K during a 5-h post-exercise period. Native whey increased phosphorylation of p70S6K and muscle protein synthesis rates to a greater extent than milk during the 5-h post exercise period.Trial registrationThis study was retrospectively registered at clinicaltrials.gov as NCT02968888.

Whey Protein Supplementation Preserves Postprandial Myofibrillar Protein Synthesis during Short-Term Energy Restriction in Overweight and Obese Adults1–3

Background: Higher dietary energy as protein during weight loss results in a greater loss of fat mass and retention of muscle mass; however, the impact of protein quality on the rates of myofibrillar protein synthesis (MPS) and lipolysis, processes that are important in the maintenance of muscle and loss of fat, respectively, are unknown.Objective: We aimed to determine how the consumption of different sources of proteins (soy or whey) during a controlled short-term (14-d) hypoenergetic diet affected MPS and lipolysis.Methods: Men (n = 19) and women (n = 21) (age 35–65 y; body mass index 28–50 kg/m2) completed a 14-d controlled hypoenergetic diet (−750 kcal/d). Participants were randomly assigned, double blind, to receive twice-daily supplements of isolated whey (27 g/supplement) or soy (26g/supplement), providing a total protein intake of 1.3 ± 0.1 g/(kg · d), or isoenergetic carbohydrate (25 g maltodextrin/supplement) resulting in a total protein intake of 0.7 ± 0.1 g/(kg · d). Before and after the dietary intervention, primed continuous infusions of L-[ring-13C6] phenylalanine and [2H5]-glycerol were used to measure postabsorptive and postprandial rates of MPS and lipolysis.Results: Preintervention, MPS was stimulated more (P < 0.05) with ingestion of whey than with soy or carbohydrate. Postintervention, postabsorptive MPS decreased similarly in all groups (all P < 0.05). Postprandial MPS was reduced by 9 ± 1% in the whey group, which was less (P < 0.05) than the reduction in soy and carbohydrate groups (28 ± 5% and 31 ± 5%, respectively; both P < 0.05) after the intervention. Lipolysis was suppressed during the postprandial period (P < 0.05), but more so with ingestion of carbohydrate (P < 0.05) than soy or whey.Conclusion: We conclude that whey protein supplementation attenuated the decline in postprandial rates of MPS after weight loss, which may be of importance in the preservation of lean mass during longer-term weight loss interventions. This trial was registered at clinicaltrials.gov as NCT01530646.

Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men

Feeding stimulates robust increases in muscle protein synthesis (MPS); however, ageing may alter the anabolic response to protein ingestion and the subsequent aminoacidaemia. With this as background, we aimed to determine in the present study the dose-response of MPS with the ingestion of isolated whey protein, with and without prior resistance exercise, in the elderly. For the purpose of this study, thirty-seven elderly men (age 71 (sd 4) years) completed a bout of unilateral leg-based resistance exercise before ingesting 0, 10, 20 or 40 g of whey protein isolate (W0-W40, respectively). Infusion of l-[1-13C]leucine and l-[ring-13C6]phenylalanine with bilateral vastus lateralis muscle biopsies were used to ascertain whole-body leucine oxidation and 4 h post-protein consumption of MPS in the fed-state of non-exercised and exercised leg muscles. It was determined that whole-body leucine oxidation increased in a stepwise, dose-dependent manner. MPS increased above basal, fasting values by approximately 65 and 90 % for W20 and W40, respectively (P < 0·05), but not with lower doses of whey. While resistance exercise was generally effective at stimulating MPS, W20 and W40 ingestion post-exercise increased MPS above W0 and W10 exercised values (P < 0·05) and W40 was greater than W20 (P < 0·05). Based on the study, the following conclusions were drawn. At rest, the optimal whey protein dose for non-frail older adults to consume, to increase myofibrillar MPS above fasting rates, was 20 g. Resistance exercise increases MPS in the elderly at all protein doses, but to a greater extent with 40 g of whey ingestion. These data suggest that, in contrast to younger adults, in whom post-exercise rates of MPS are saturated with 20 g of protein, exercised muscles of older adults respond to higher protein doses.

Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men

We aimed to determine the effect of consuming pure isolated micellar casein or pure whey protein isolate on rates of myofibrillar protein synthesis (MPS) at rest and after resistance exercise in elderly men. Healthy elderly men (72 (sem 1) years; BMI 26·4 (sem 0·7) kg/m²) were divided into two groups (n 7 each) who received a primed, constant infusion of l-[ring-¹³C₆]phenylalanine to measure MPS at rest and during 4 h of exercise recovery. Participants performed unilateral leg resistance exercise followed by the consumption of isonitrogenous quantities (20 g) of casein or whey. Blood essential amino acids and leucine concentration peaked 60 min post-drink and were greater in amplitude after whey protein ingestion (both, P < 0·05). MPS in the rested leg was 65 % higher (P = 0·002) after ingestion of whey (0·040 (sem 0·003) %/h) when compared with micellar casein (0·024 (sem 0·002) %/h). Similarly, resistance exercise-stimulated rates of MPS were greater (P < 0·001) after whey ingestion (0·059 (sem 0·005) %/h) v. micellar casein (0·035 (sem 0·002) %/h). We conclude that ingestion of isolated whey protein supports greater rates of MPS than micellar casein both at rest and after resistance exercise in healthy elderly men. This result is probably related to a greater hyperaminoacidaemia or leucinaemia with whey ingestion.

Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise

Ingestion of whey or casein yields divergent patterns of aminoacidemia that influence whole-body and skeletal muscle myofibrillar protein synthesis (MPS) after exercise. Direct comparisons of the effects of contrasting absorption rates exhibited by these proteins are confounded by their differing amino acid contents. Our objective was to determine the effect of divergent aminoacidemia by manipulating ingestion patterns of whey protein alone on MPS and anabolic signaling after resistance exercise. In separate trials, 8 healthy men consumed whey protein either as a single bolus (BOLUS; 25-g dose) or as repeated, small, "pulsed" drinks (PULSE; ten 2.5-g drinks every 20 min) to mimic a more slowly digested protein. MPS and phosphorylation of signaling proteins involved in protein synthesis were measured at rest and after resistance exercise. BOLUS increased blood essential amino acid (EAA) concentrations above those of PULSE (162% compared with 53%, P < 0.001) 60 min after exercise, whereas PULSE resulted in a smaller but sustained increase in aminoacidemia that remained elevated above BOLUS amounts later (180-220 min after exercise, P < 0.05). Despite an identical net area under the EAA curve, MPS was elevated to a greater extent after BOLUS than after PULSE early (1-3 h: 95% compared with 42%) and later (3-5 h: 193% compared with 121%) (both P < 0.05). There were greater changes in the phosphorylation of the Akt-mammalian target of rapamycin pathway after BOLUS than after PULSE. Rapid aminoacidemia in the postexercise period enhances MPS and anabolic signaling to a greater extent than an identical amount of protein fed in small pulses that mimic a more slowly digested protein. A pronounced peak aminoacidemia after exercise enhances protein synthesis. This trial was registered at clinicaltrials.gov as NCT01319513.

Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men

Sarcopenia has been attributed to a diminished muscle protein synthetic response to food intake. Differences in digestion and absorption kinetics of dietary protein, its amino acid composition, or both have been suggested to modulate postprandial muscle protein accretion. The objective was to compare protein digestion and absorption kinetics and subsequent postprandial muscle protein accretion after ingestion of whey, casein, and casein hydrolysate in healthy older adults. A total of 48 older men aged 74 ± 1 y (mean ± SEM) were randomly assigned to ingest a meal-like amount (20 g) of intrinsically l-[1-(13)C]phenylalanine-labeled whey, casein, or casein hydrolysate. Protein ingestion was combined with continuous intravenous l-[ring-(2)H(5)]phenylalanine infusion to assess in vivo digestion and absorption kinetics of dietary protein. Postprandial mixed muscle protein fractional synthetic rates (FSRs) were calculated from the ingested tracer. The peak appearance rate of dietary protein-derived phenylalanine in the circulation was greater with whey and casein hydrolysate than with casein (P < 0.05). FSR values were higher after whey (0.15 ± 0.02%/h) than after casein (0.08 ± 0.01%/h; P < 0.01) and casein hydrolysate (0.10 ± 0.01%/h; P < 0.05) ingestion. A strong positive correlation (r = 0.66, P < 0.01) was observed between peak plasma leucine concentrations and postprandial FSR values. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. This effect is attributed to a combination of whey's faster digestion and absorption kinetics and higher leucine content. This trial was registered at clinicaltrials.gov as NCT00557388.

Whey and casein labeled withl-[1-13C]leucine and muscle protein synthesis: effect of resistance exercise and protein ingestion

Muscle protein turnover following resistance exercise and amino acid availability are relatively well described. By contrast, the beneficial effects of different sources of intact proteins in relation to exercise need further investigation. Our objective was to compare muscle anabolic responses to a single bolus intake of whey or casein after performance of heavy resistance exercise. Young male individuals were randomly assigned to participate in two protein trials (n = 9) or one control trial (n = 8). Infusion of l-[1-(13)C]leucine was carried out, and either whey, casein (0.3 g/kg lean body mass), or a noncaloric control drink was ingested immediately after exercise. l-[1-(13)C]leucine-labeled whey and casein were used while muscle protein synthesis (MPS) was assessed. Blood and muscle tissue samples were collected to measure systemic hormone and amino acid concentrations, tracer enrichments, and myofibrillar protein synthesis. Western blots were used to investigate the Akt signaling pathway. Plasma insulin and branched-chain amino acid concentrations increased to a greater extent after ingestion of whey compared with casein. Myofibrillar protein synthesis was equally increased 1-6 h postexercise after whey and casein intake, both of which were higher compared with control (P < 0.05). Phosphorylation of Akt and p70(S6K) was increased after exercise and protein intake (P < 0.05), but no differences were observed between the types of protein except for total 4E-BP1, which was higher after whey intake than after casein intake (P < 0.05). In conclusion, whey and casein intake immediately after resistance exercise results in an overall equal MPS response despite temporal differences in insulin and amino acid concentrations and 4E-BP1.

Isonitrogenous protein sources with different leucine contents differentially effect translation initiation and protein synthesis in skeletal muscle

Leucine has been shown to stimulate phosphorylation of the initiation factors 4E‐BP1 and p70S6K (S6K) and activate skeletal muscle protein synthesis (MPS) in a dose‐dependant response (J. Nutr. 135:376–382, 2005). It is unclear if protein sources with different levels of leucine will produce the same response. This study examined 3 levels of protein intake (10%, 20% and 30% of energy) from 2 sources (whey vs wheat) that differ in leucine content (~13% vs. ~7%) on the potential to activate translation factors and MPS. Male rats (250g) were trained for 5d to eat 3 meals/d consisting of 14/56/30% calories from protein, carbohydrates and fats. Rats were sacrificed on experiment day 90 min after consuming one of the meals or fasted. Measurements include plasma insulin and amino acids, MPS via D5‐Phe incooperation, and phosphorylation of translation factors 4E‐BP1 and S6K. Whey ingestion caused a significantly greater phosphorylation of S6K and 4E‐BP1 than wheat in 10% and 20% protein groups, with no difference between the two at 30%. MPS followed a similar pattern. Phosphorylation of the translation factors and MPS were similar for 10% whey and 20% wheat and similar for 20% whey and 30% wheat. These findings are consistent with the role of leucine as a regulatory substrate for MPS and suggest that leucine content of protein sources is a major determinant of protein quality for maximizing MPS.Support: National Dairy Council

Metabolic effects of amino acid mixtures and whey protein in healthy subjects: studies using glucose-equivalent drinks

Background:Milk protein, in particular the whey fraction, has been shown to display insulinotrophic properties in healthy persons and persons with type 2 diabetes. In parallel to the hyperinsulinemia, a pronounced postprandial rise of certain amino acids and of glucose-dependent insulinotrophic polypeptide (GIP) was observed in plasma.Objective:The objective of the study was to determine to what extent the insulinotrophic properties of whey could be simulated by specific amino acid mixtures.Design:Twelve healthy volunteers were served drinks consisting of pure glucose (reference drink) or glucose supplemented with free amino acids or whey proteins (test drinks).Results:A test drink with the branched-chain amino acids isoleucine, leucine, and valine resulted in significantly higher insulin responses than did the glucose reference. A drink containing glucose and leucine, isoleucine, valine, lysine, and threonine mimicked the glycemic and insulinemic responses seen after whey ingestion. With consumption of this drink, the glucose area under the curve (AUC) was 44% smaller (P< 0.05) and the insulin AUC was 31% larger (NS) than with consumption of the reference drink. With consumption of the whey drink, the AUCs were 56% smaller (glucose; P< 0.05) and 60% larger (insulin; P< 0.05), respectively, than with the reference drink. The whey drink was accompanied by an 80% greater GIP response (P< 0.05), whereas the drinks containing free amino acids did not significantly affect GIP secretion.Conclusion:A mixture of leucine, isoleucine, valine, lysine, and threonine resulted in glycemic and insulinemic responses closely mimicking those seen after whey ingestion in the absence of an additional effect of GIP and glucagon-like peptide 1.

Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects

Whey proteins have insulinotropic effects and reduce the postprandial glycemia in healthy subjects. The mechanism is not known, but insulinogenic amino acids and the incretin hormones seem to be involved. The aim was to evaluate whether supplementation of meals with a high glycemic index (GI) with whey proteins may increase insulin secretion and improve blood glucose control in type 2 diabetic subjects. Fourteen diet-treated subjects with type 2 diabetes were served a high-GI breakfast (white bread) and subsequent high-GI lunch (mashed potatoes with meatballs). The breakfast and lunch meals were supplemented with whey on one day; whey was exchanged for lean ham and lactose on another day. Venous blood samples were drawn before and during 4 h after breakfast and 3 h after lunch for the measurement of blood glucose, serum insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1). The insulin responses were higher after both breakfast (31%) and lunch (57%) when whey was included in the meal than when whey was not included. After lunch, the blood glucose response was significantly reduced [-21%; 120 min area under the curve (AUC)] after whey ingestion. Postprandial GIP responses were higher after whey ingestion, whereas no differences were found in GLP-1 between the reference and test meals. It can be concluded that the addition of whey to meals with rapidly digested and absorbed carbohydrates stimulates insulin release and reduces postprandial blood glucose excursion after a lunch meal consisting of mashed potatoes and meatballs in type 2 diabetic subjects.

Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects

Background:Whey proteins have insulinotropic effects and reduce the postprandial glycemia in healthy subjects. The mechanism is not known, but insulinogenic amino acids and the incretin hormones seem to be involved. Objective:The aim was to evaluate whether supplementation of meals with a high glycemic index (GI) with whey proteins may increase insulin secretion and improve blood glucose control in type 2 diabetic subjects. Design:Fourteen diet-treated subjects with type 2 diabetes were served a high-GI breakfast (white bread) and subsequent high-GI lunch (mashed potatoes with meatballs). The breakfast and lunch meals were supplemented with whey on one day; whey was exchanged for lean ham and lactose on another day. Venous blood samples were drawn before and during 4 h after breakfast and 3 h after lunch for the measurement of blood glucose, serum insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1). Results:The insulin responses were higher after both breakfast (31%) and lunch (57%) when whey was included in the meal than when whey was not included. After lunch, the blood glucose response was significantly reduced [−21%; 120 min area under the curve (AUC)] after whey ingestion. Postprandial GIP responses were higher after whey ingestion, whereas no differences were found in GLP-1 between the reference and test meals. Conclusions:It can be concluded that the addition of whey to meals with rapidly digested and absorbed carbohydrates stimulates insulin release and reduces postprandial blood glucose excursion after a lunch meal consisting of mashed potatoes and meatballs in type 2 diabetic subjects.

Metabolic Responses To Ingestion Of Whey Protein In Active Men

Effects of dietary protein intake on skeletal muscle accretion are not well understood. PURPOSE To determine plasma amino acid appearance rate and hormonal responses of active men after ingestion of whey protein. METHODS Ten healthy, active (participating in at least 4 hours of structured exercise/week) men ingested 52 grams of whey protein isolate following an overnight fast. Blood was collected at baseline and 60, 180, 360, and 480 minutes after consumption for analysis of plasma concentrations of leucine (LEU), glutamine (GLN), insulin, testosterone, growth hormone (GH), insulin-like growth factor-1 (IGF-1), cortisol and glucagon. RESULTS LEU, GLN and insulin concentrations peaked 60 minutes after consumption with increases of 349 ± 97, 129 ± 20, and 153 ± 37 % respectively, from baseline assessment (p < 0.05). GH concentration increased (p < 0.05) from 2.9 ± 0.4 ng/ml to 8.8 ± 5.3 ng/ml three hours after whey ingestion. Plasma concentrations of testosterone, IGF-1, cortisol and glucagon did not fluctuate significantly (p > 0.05) from baseline throughout the 8-hour period. CONCLUSION These data suggest that the metabolic responses that could potentially favor anabolism are maximal relatively soon (1–3 hours) after consumption of a whey protein load. Supported by a grant from NEXT Proteins International, Inc.

Some thermal effects on the pig of the ingestion of liquid feed at various temperatures

SUMMARY1. Experiments have been performed to determine the thermal effects, on pigs, of the ingestion of whey at various temperatures while housed at various air temperatures.2. Measurements of carotid artery and rectal temperatures showed that a general cooling of deep-body tissues occurred after the ingestion of cool whey.3. Measurements of rectal and skin temperatures, and observations of respiratory rate and shivering activity, indicated that thermo-regulatory responses were induced by the ingestion of cool whey; the nature of the responses was dependent on the air temperature.4. The results indicate that the temperature of liquid food offered to animals is a significant parameter in their climatic environment.