Oct 2019 DOI 10.14302/issn.2379-7835.ijn-19-3011
Fujii TakakoCorresponding author
Exercise Nutrition Laboratory, Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
The skeletal muscle mass varies by race. Dietary habits over generations are a factor that influences the skeletal muscle mass, as well as genetic factors. Therefore, we investigated the effects of diets with different macronutrient contents on exercise-induced muscle hypertrophy in rats. Male 4-week-old Sprague–Dawley rats were randomly divided into three groups: a normal-diet (N), high-protein diet (HP) and high-fat diet (HF) group. The food intake was manipulated to gain comparable body weight across the three groups. All rats were performed a climbing exercise training for 8 weeks. The final body weight and weight of the liver, kidneys and adipose tissues did not significantly differ among the groups. The flexor hallucis longus was significantly higher in the HF group than in the HP group. The total lipid content in the muscle was significantly higher in the HF group than in the N group, while it did not differ significantly between the HF and HP groups. There were no marked differences in the water or protein content in the muscle among the groups. The plasma amino acid concentration was significantly or tended to be lower in the HP group than in the HF or N group, except for the branched-chain amino acid concentration, which tended to be higher after ingesting the HP diet than other diets. These findings suggest that consuming an HP diet is not likely to facilitate exercise-induced muscle hypertrophy, partly due to the plasma amino acid imbalance induced by habitual HP diet consumption.
Sep 2016 DOI 10.14302/issn.2574-450X.jom-16-1062
Gudala MeghanaCorresponding author
Division of Pediatric Endocrinology, Baystate Children’s Hospital, 50 Wason Avenue, Springfield, Massachusetts 01199
Background: Obese adults with Type 2 Diabetes (T2D) have shown differences in body composition and response to varying diets when compared to obese adults without T2D. This difference in body composition affects management options for obesity. Such studies have not been done on adolescents thus far. Objectives: To estimate differences in fat mass at baseline as well as following a two-week high protein liquid diet in obese adolescents with and without T2D. Methods: Thiswas a pilot study using a non-randomized, unblinded pre/post intervention design without a control group. We planned to recruit 40 subjects (20 per group, with and without T2D) from ages 10 – 19 years, with Body mass index (BMI) ≥ 95 percentile. Body fat mass was measured via the Bod Pod® at baseline and after two weeks of following the diet with Ensure High Protein shakes. Change in fat mass is presented as mean differences and 95% confidence intervals. Results: We recruited 28 subjects, 19 completed the study and 12 were compliant with the diet. The mean difference in fat mass percent from baseline in subjects who completed the study (n=19) and without T2D was 1.4 (95% confidence interval (CI): -2.1 to -0.8) and in subjects with T2D was 1.2 (95% CI: -3.6 to 1.24). Conclusion: We did not find any meaningful difference in fat mass at baseline or after following a two-week high protein diet between the groups. High dropout rate and noncompliance with the diet were major limitations.