A Review of Weight Control Strategies and Their Effects on the Regulation of Hormonal Balance

The estimated prevalence of obesity in the USA is 72.5 million adults with costs attributed to obesity more than 147 billion dollars per year. Though caloric restriction has been used extensively in weight control studies, short-term success has been difficult to achieve, with long-term success of weight control being even more elusive. Therefore, novel approaches are needed to control the rates of obesity that are occurring globally. The purpose of this paper is to provide a synopsis of how exercise, sleep, psychological stress, and meal frequency and composition affect levels of ghrelin, cortisol, insulin GLP-1, and leptin and weight control. We will provide information regarding how hormones respond to various lifestyle factors which may affect appetite control, hunger, satiety, and weight control

Effects of Capsaicin and Evodiamine Ingestion on Energy Expenditure and Fat Oxidation at Rest and After Moderately-Intense Exercise in Young Men

Capsaicin and evodiamine are two thermogenic agents each recognized for their ability to stimulate the sympathetic nervous system and are thus found in many dietary supplements. Therefore, the purpose of this study was to observe the effects that capsaicin and evodiamine have on hemodynamics, energy expenditure, and markers of lipid oxidation while at rest and after a single bout of moderate-intensity exercise in young men. In a randomized, cross-over design, 11 men orally ingested 500 mg of capsaicin, evodiamine, or placebo while at rest after 30 minutes of resting energy expenditure assessment using open-circuit spirometry. After an additional 30 minutes of rest after supplement ingestion, resting energy expenditure was assessed again for 30 minutes. After the second resting energy expenditure assessment, treadmill exercise was performed until expending approximately 500 kilocalories (~30 minutes) at 65% peak oxygen consumption. Energy expenditure was assessed for another 30 minutes into the post-exercise period. Heart rate and blood pressure, core temperature, and venous blood samples were obtained 30 minutes before and one hour after supplement ingestion (i.e. immediately pre-exercise), and immediately after and 45 minutes post-exercise. Markers of lipid oxidation (serum glycerol, free fatty acids, serum glucose, epinephrine, and norepinephrine) were determined spectrophotometrically and with ELISA. Two-way analyses of variance (ANOVA) were performed for each dependent variable (p ≤ 0.05). Significant main effects for Time existed for hemodynamics, energy expenditure, serum catecholamines and markers of fat oxidation immediately following exercise (p \u3c 0.05). However, no significant Supplement x Time interactions were noted for any criterion variable (p \u3e 0.05), suggesting no preferential difference between supplements. Neither capsaicin nor evodiamine, at a single dose of 500 mg, are effective at inducing thermogenesis and increasing fat oxidation at rest or during exercise in young men

Ingestion of 10 grams of whey protein prior to a single bout of resistance exercise does not augment Akt/mTOR pathway signaling compared to carbohydrate

Background: This study examined the effects of a whey protein supplement in conjunction with an acute bout of lower body resistance exercise, in recreationally-active males, on serum insulin and insulin like growth factor 1 (IGF-1) and Akt/mTOR signaling markers indicative of muscle protein synthesis: insulin receptor substrate 1 (IRS-1), AKT, mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K) and 4E-binding protein 1 (4E-BP1).Methods: In a randomized, double-blind, cross-over design, 10 males ingested 1 week apart, either 10 g of whey protein (5.25 g EAAs) or carbohydrate (maltodextrose), 30 min prior to a lower-body resistance exercise bout. The resistance exercise bout consisted of 4 sets of 8-10 reps at 80% of the one repetition maximum (RM) on the angled leg press and knee extension exercises. Blood and muscle samples were obtained prior to, and 30 min following supplement ingestion and 15 min and 120 min post-exercise. Serum and muscle data were analyzed using two-way ANOVA.Results: No significant differences were observed for IGF-1 (p > 0.05). A significant main effect for Test was observed for serum insulin (p 0.05). For the Akt/MTOR signaling intermediates, no significant Supplement × Test interactions were observed (p > 0.05). However, significant main effects for Test were observed for phosphorylated concentrations of IRS, mTOR, and p70S6K, as all were elevated at 15 min post-exercise (p < 0.05). Additionally, a significant main effect for Test was noted for 4E-BP1 (p < 0.05), as it was decreased at 15 min post-exercise.Conclusion: Ingestion of 10 g of whey protein prior to an acute bout of lower body resistance exercise had no significant preferential effect compared to carbohydrate on systemic and cellular signaling markers indicative of muscle protein synthesis in untrained individuals

International Society of Sports Nutrition position stand: protein and exercise

<p>Abstract</p> <p>Position Statement</p> <p>The following seven points related to the intake of protein for healthy, exercising individuals constitute the position stand of the Society. They have been approved by the Research Committee of the Society. 1) Vast research supports the contention that individuals engaged in regular exercise training require more dietary protein than sedentary individuals. 2) Protein intakes of 1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training. 3) When part of a balanced, nutrient-dense diet, protein intakes at this level are not detrimental to kidney function or bone metabolism in healthy, active persons. 4) While it is possible for physically active individuals to obtain their daily protein requirements through a varied, regular diet, supplemental protein in various forms are a practical way of ensuring adequate and quality protein intake for athletes. 5) Different types and quality of protein can affect amino acid bioavailability following protein supplementation. The superiority of one protein type over another in terms of optimizing recovery and/or training adaptations remains to be convincingly demonstrated. 6) Appropriately timed protein intake is an important component of an overall exercise training program, essential for proper recovery, immune function, and the growth and maintenance of lean body mass. 7) Under certain circumstances, specific amino acid supplements, such as branched-chain amino acids (BCAA's), may improve exercise performance and recovery from exercise.</p

Obesity: Prevalence, Theories, Medical Consequences, Management, and Research Directions

Obesity and its associated disorders are a growing epidemic across the world. Many genetic, physiological, and behavioral factors play a role in the etiology of obesity. Diet and exercise are known to play a valuable role in the treatment and prevention of obesity and associated disorders such as hypertension, heart disease, and diabetes. Therefore, the purpose of this review is to examine the prevalence, etiology, consequences, and treatment of obesity

Variation in Individual Responses to Time-Restricted Feeding and Resistance Training

Time-restricted feeding (TRF) is a form of intermittent fasting which limits all caloric intake to a certain period of time each day in an attempt to reduce daily energy intake, promote weight loss, and improve health. Resistance training (RT) has been reported to increase muscular strength and improve body composition. Very limited information is available on the combination of TRF and RT. The purpose of this study was to examine the variation in individual body composition, dietary intake, and muscular performance responses to an 8-wk TRF and RT program. Healthy males (n = 20; age = 22 ± 3 y; BMI = 27 ± 6 kg/m2; % fat = 22 ± 6 % wt) were randomized to TRF + RT or RT alone for 8 wks. RT was performed 3 dys/wk and consisted of alternate workouts of upper and lower body using a resistance progression scheme. TRF limited energy intake to a 4-hr period on the 4 dys/wk when RT was not performed. Energy intake was not restricted in either group, and eating times were not specified in the RT alone group. Body composition, muscular performance, and dietary records were assessed at 0, 4, and 8 wks. Inter- and intra-individual variations in outcome measures were estimated by hierarchical linear growth modeling. The amount of variability attributable to characteristics between or within participants was evaluated from variance estimates. For TRF + RT, percent changes ranged from -5.5 to +2.6% for body weight, -22.1 to +9.4% for fat mass, -7.7 to +4.6% for lean body mass, +3.4 to +30.4% for bench press 1-RM, and +10.1 to +67.6% for leg press 1-RM. For RT alone, percent changes ranged from -6.6 to +2.1% for body weight, -14.4 to +12.6% for fat mass, -4.1 to +3.9% for lean body mass, +4.9 to +12.9% for bench press 1-RM, and +14.3 to +37.7% for leg press 1-RM. Percentages of total variability attributed to inter-individual factors ranged from 3.3 to 49.2% for dietary measures, 59.0 to 93.9% for muscular performance, and 97.0 to 99.6% for body composition. Remaining variability was attributed to intra-individual factors. Individual responses to the study interventions varied widely. Differences between individuals were an important source of variability, indicating participant samples should be homogenous and/or quite large to examine changes in body composition or muscular performance using nutrition and exercise interventions