Erin E. Quann

Whey Protein Supplementation During Resistance Training Augments Lean Body Mass

Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. Objective: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22). Methods: All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (∼9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months. Results: Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass−1, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. Conclusions: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.

Effects of amino acids supplement on physiological adaptations to resistance training

INTRODUCTION Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. PURPOSE The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armor (MA); Abbott Laboratories, Abbott Park, IL) containing beta-hydroxy-beta-methylbutyrate (HMB) on hormonal and muscle damage markers in response to 12 wk of resistance exercise. METHODS Seventeen healthy men (mean body mass: 77.9 +/- 7.2 kg; mean height: 174.3 +/- 12.4 cm; mean age: 22.9 +/- 3.8 yr) were matched and randomized into two groups and performed 12 wk of periodized heavy resistance training while supplementing with either MA or an isocaloric, isonitrogenous placebo (CON). Every 2 wk during the 12-wk intervention, resting blood draws were obtained, and muscle strength and power were measured. In addition, blood draws were obtained before, during, and after a standardized resistance exercise challenge performed pre-, mid-, and posttraining. RESULTS Lean body mass, muscle strength, and muscle power significantly (P <or= 0.05) increased in both groups after training; however, MA supplementation augmented these responses to a significantly greater extent when compared with the CON group. MA supplementation promoted increases in resting and exercise-induced testosterone and resting growth hormone concentrations. In addition, MA reduced preexercise cortisol concentrations. Throughout the training protocol, MA attenuated circulating creatine kinase and malondealdehyde compared with the CON group, suggesting that MA might have influenced a reduction in muscle damage. CONCLUSION MA supplementation beneficially affected training-induced changes in lean body mass, muscle strength, and power, as well as hormonal responses and markers of muscle damage in response to 12 wk of resistance exercise training when compared with an isonitrogenous control.

Acute ingestion of a novel whey-derived peptide improves vascular endothelial responses in healthy individuals: a randomized, placebo controlled trial

BackgroundWhey protein is a potential source of bioactive peptides. Based on findings from in vitro experiments indicating a novel whey derived peptide (NOP-47) increased endothelial nitric oxide synthesis, we tested its effects on vascular function in humans.MethodsA randomized, placebo-controlled, crossover study design was used. Healthy men (n = 10) and women (n = 10) (25 ± 5 y, BMI = 24.3 ± 2.3 kg/m2) participated in two vascular testing days each preceded by 2 wk of supplementation with a single dose of 5 g/day of a novel whey-derived peptide (NOP-47) or placebo. There was a 2 wk washout period between trials. After 2 wk of supplementation, vascular function in the forearm and circulating oxidative stress and inflammatory related biomarkers were measured serially for 2 h after ingestion of 5 g of NOP-47 or placebo. Macrovascular and microvascular function were assessed using brachial artery flow mediated dilation (FMD) and venous occlusion strain gauge plethysmography.ResultsBaseline peak FMD was not different for Placebo (7.7%) and NOP-47 (7.8%). Placebo had no effect on FMD at 30, 60, and 90 min post-ingestion (7.5%, 7.2%, and 7.6%, respectively) whereas NOP-47 significantly improved FMD responses at these respective postprandial time points compared to baseline (8.9%, 9.9%, and 9.0%; P < 0.0001 for time × trial interaction). Baseline reactive hyperemia forearm blood flow was not different for placebo (27.2 ± 7.2%/min) and NOP-47 (27.3 ± 7.6%/min). Hyperemia blood flow measured 120 min post-ingestion (27.2 ± 7.8%/min) was unaffected by placebo whereas NOP-47 significantly increased hyperemia compared to baseline (29.9 ± 7.8%/min; P = 0.008 for time × trial interaction). Plasma myeloperoxidase was increased transiently by both NOP-47 and placebo, but there were no changes in markers inflammation. Plasma total nitrites/nitrates significantly decreased over the 2 hr post-ingestion period and were lower at 120 min after placebo (-25%) compared to NOP-47 (-18%).ConclusionThese findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function.

National trends in beverage consumption in children from birth to 5 years: analysis of NHANES across three decades

BackgroundGiven the epidemic of childhood obesity, it is crucial to assess food and beverage intake trends. Beverages can provide a large number of calories and since consumption patterns seem to develop at a young age we examined beverage consumption trends over three decades. The objective of this study was to assess the beverage (milk, fruit juice, fruit drinks, tea, soy beverages, and soft drinks) consumption trends in children <1-5 years of age.MethodsData from individuals ages <1-5 years participating in the National Health and Nutrition Examination Survey (NHANES) from 1976–1980, 1988–1994 and 2001–2006 were used to assess beverage consumption and associated calorie and nutrient intakes.ResultsDuring the NHANES 1976–1980 and 1988–1994 periods, approximately 84–85% of children were consuming milk, whereas only 77% were consuming milk during NHANES 2001–2006. Flavored milk intake was relatively low, but increased to 14% during the last decade (p < 0.001). Fruit juice consumption increased dramatically during NHANES 2001–2006 to more than 50% of the population compared to about 30% in the older surveys (p < 0.001). No significant changes were observed in fruit drink intake across all three decades with 35-37% of this population consuming fruit drinks. At least 30% of children consumed soft drinks. Milk was the largest beverage calorie contributor in all three decades surveyed and was the primary contributor of calcium (52-62%), phosphorus (37-42%), magnesium (27-28%), and potassium (32-37%). Fruit juice and fruit drinks each provided 8-10% of calories with soft drinks providing 5-6% of calories. Fruit juice was an important provider of potassium (16-19%) and magnesium (11%). Fruit drinks provided less than 5% of nutrients examined and soft drinks provided very little of the nutrients evaluated.ConclusionsGiven concerns about childhood obesity and the need to meet nutrition requirements, it is prudent that parents, educators and child caretakers replace some of the nutrient poor beverages young children are currently consuming with more nutrient dense sources like low-fat and fat-free milk.

Effects of dietary carbohydrate restriction versus low-fat diet on flow-mediated dilation

We previously reported that a carbohydrate-restricted diet (CRD) ameliorated many of the traditional markers associated with metabolic syndrome and cardiovascular risk compared with a low-fat diet (LFD). There remains concern how CRD affects vascular function because acute meals high in fat have been shown to impair endothelial function. Here, we extend our work and address these concerns by measuring fasting and postprandial vascular function in 40 overweight men and women with moderate hypertriacylglycerolemia who were randomly assigned to consume hypocaloric diets (approximately 1500 kcal) restricted in carbohydrate (percentage of carbohydrate-fat-protein = 12:59:28) or LFD (56:24:20). Flow-mediated dilation of the brachial artery was assessed before and after ingestion of a high-fat meal (908 kcal, 84% fat) at baseline and after 12 weeks. Compared with the LFD, the CRD resulted in a greater decrease in postprandial triacylglycerol (-47% vs -15%, P = .007), insulin (-51% vs -6%, P = .009), and lymphocyte (-12% vs -1%, P = .050) responses. Postprandial fatty acids were significantly increased by the CRD compared with the LFD (P = .033). Serum interleukin-6 increased significantly over the postprandial period; and the response was augmented in the CRD (46%) compared with the LFD (-13%) group (P = .038). After 12 weeks, peak flow-mediated dilation at 3 hours increased from 5.1% to 6.5% in the CRD group and decreased from 7.9% to 5.2% in the LFD group (P = .004). These findings show that a 12-week low-carbohydrate diet improves postprandial vascular function more than a LFD in individuals with atherogenic dyslipidemia.

Effects of exercise at different times on postprandial lipemia and endothelial function.

PURPOSE The purpose of this study was to examine the effects of previous exercise on metabolic, hormonal, and endothelial responses to an oral fat-tolerance test (OFTT). METHODS Twelve healthy, recreationally trained men (age = 22.3 +/- 2.5 yr, weight = 80.7 +/- 12.4 kg, BMI = 25.1 +/- 3.1 kg.m(-2)) volunteered for this study. In a crossover fashion, subjects completed three OFTT trials that involved no exercise (NoEx) or exercise performed 16 h (EX-16) or 4 h (EX-4) before the ingestion of a meal (13 kcal.kg(-1) and 1.4 g of fat per kilogram of body weight). Blood was collected before and after the meal and hourly for 6 h. Brachial artery reactivity was measured using ultrasound before and at 2, 4, and 6 h after the meal. Dietary intake and exercise were standardized 4 d before the OFTT. The exercise session consisted of six resistance exercises and 30 min of running on a treadmill. The washout period between trials was, on average, 5 d. RESULTS Compared with NoEx, there were significant (P < 0.05) decreases in triglyceride area under the curve (AUC) during EX-16 (-26%) and EX-4 (-15%). Compared with NoEx, there were decreases in insulin AUC during EX-16 (-7%, P < 0.05) and EX-4 (-5%, NS). EX-4 resulted in a significantly larger fasting arterial diameter than EX-16 and NoEx, but there were no other significant effects on endothelial function. Lipemic variables did not show correlations with endothelium function for any of the trials. CONCLUSION An acute exercise session, regardless of the time point chosen (i.e., EX-16 or EX-4), reduced to a similar extent the total and incremental lipemic responses compared with the NoEx condition.

Effects of Carnitine Supplementation on Flow-Mediated Dilation and Vascular Inflammatory Responses to a High-Fat Meal in Healthy Young Adults

Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.

Dietary carbohydrate restriction improves insulin sensitivity, blood pressure, microvascular function, and cellular adhesion markers in individuals taking statins ☆

Statins positively impact plasma low-density lipoprotein cholesterol, inflammation and vascular endothelial function (VEF). Carbohydrate restricted diets (CRD) improve atherogenic dyslipidemia, and similar to statins, have been shown to favorably affect markers of inflammation and VEF. No studies have examined whether a CRD provides additional benefit beyond that achieved by habitual statin use. We hypothesized that a CRD (<50 g carbohydrate/d) for 6 weeks would improve lipid profiles and insulin sensitivity, reduce blood pressure, decrease cellular adhesion and inflammatory biomarkers, and augment VEF (flow-mediated dilation and forearm blood flow) in statin users. Participants (n = 21; 59.3 ± 9.3 y, 29.5 ± 3.0 kg/m(2)) decreased total caloric intake by approximately 415 kcal at 6 weeks (P < .001). Daily nutrient intakes at baseline (46/36/17% carb/fat/pro) and averaged across the intervention (11/58/28% carb/fat/pro) demonstrated dietary compliance, with carbohydrate intake at baseline nearly 5-fold greater than during the intervention (P < .001). Compared to baseline, both systolic and diastolic blood pressure decreased after 3 and 6 weeks (P < .01). Peak forearm blood flow, but not flow-mediated dilation, increased at week 6 compared to baseline and week 3 (P ≤ .03). Serum triglyceride, insulin, soluble E-Selectin and intracellular adhesion molecule-1 decreased (P < .01) from baseline at week 3, and this effect was maintained at week 6. In conclusion, these findings demonstrate that individuals undergoing statin therapy experience additional improvements in metabolic and vascular health from a 6 weeks CRD as evidenced by increased insulin sensitivity and resistance vessel endothelial function, and decreased blood pressure, triglycerides, and adhesion molecules.

Low-carbohydrate Diets Promote a More Favorable Body Composition Than Low-fat Diets

A PRIMARY CONCERN WITH CONVENTIONAL WEIGHT LOSS APPROACHES IS THE LOSS OF LEAN BODY MASS THAT OCCURS WHEN FAT MASS IS DECREASED. CONSUMING MODERATE PROTEIN, WHILE RESTRICTING CARBOHYDRATE, ALLOWS FOR GREATER PRESERVATION OF LEAN BODY MASS. A LOW-CARBOHYDRATE DIET IN CONJUNCTION WITH PERIODIZED RESISTANCE TRAINING PROMOTES GREATER FAT LOSS WHILE PRESERVING LEAN BODY MASS AND PROMOTING ROBUST IMPROVEMENTS IN METABOLIC HEALTH.

Consuming the daily recommended amounts of dairy products would reduce the prevalence of inadequate micronutrient intakes in the United States: diet modelling study based on NHANES 2007–2010

Abstract Background: A large portion of Americans are not meeting the Dietary Reference Intakes (DRI) for several essential vitamins and minerals due to poor dietary choices. Dairy products are a key source of many of the nutrients that are under consumed, but children and adults do not consume the recommended amounts from this food group. This study modelled the impact of meeting daily recommended amounts of dairy products on population-based nutrient intakes. Methods: Two-day 24-h dietary recalls collected from participants ≥2 years (n = 8944) from the 2007–2010 What We Eat in America, National Health and Nutrition Examination Survey (NHANES) were analysed. Databases available from the WWEIA/NHANES and the United States Department of Agriculture (USDA) were used to determine nutrient, food group, and dietary supplement intakes. Modelling was performed by adding the necessary number of dairy servings, using the dairy composite designed by USDA, to each participant’s diet to meet the dairy recommendations outlined by the 2010 Dietary Guidelines for Americans. All analyses included sample weights to account for the NHANES survey design. Results: The majority of children 4 years and older (67.4–88.8 %) and nearly all adults (99.0–99.6 %) fall below the recommended 2.5–3 daily servings of dairy products. Increasing dairy consumption to recommended amounts would result in a significant reduction in the percent of adults with calcium, magnesium, and vitamin A intakes below the Estimated Average Requirement (EAR) when considering food intake alone (0–2.0 vs. 9.9–91.1 %; 17.3–75.0 vs. 44.7–88.5 %; 0.1–15.1 vs. 15.3–48.0 %, respectively), as well as food and dietary supplement intake. Minimal, but significant, improvements were observed for the percent of people below the EAR for vitamin D (91.7–99.9 vs. 91.8–99.9 %), and little change was achieved for the large percentage of people below the Adequate Intake for potassium. Conclusions: Increasing dairy food consumption to recommended amounts is one practical dietary change that could significantly improve the population’s adequacy for certain vitamins and minerals that are currently under-consumed, as well as have a positive impact on health.