Supplement Doctor's Blog

ABSTRACT - Different dietary proteins vary in their ability to influence satiety and reduce food intake. The present study compared the effects of four protein meals, whey, tuna, turkey and egg albumin, on postprandial glucose and insulin concentrations as well as on appetite measures and energy intake in twenty-two lean, healthy men. This was a randomised, cross-over design study where participants consumed four liquid test meals on separate occasions followed by the collection of regular blood samples (fasting, +30, 60, 90, 120, 180 and 240 min). They were then offered a buffet meal 4 h later. The blood glucose response after the consumption of the test meal, as an incremental area under the curve (AUC), was significantly lower with the whey meal than with the turkey (P < 0.023) and egg (P < 0.001) meals, but it was not lower than with the tuna meal (P < 0.34). The AUC blood insulin after the consumption of the test meal was significantly higher with the whey meal than with the tuna, turkey and egg meals (all P < 0.001). The AUC rating of hunger was significantly lower with the whey meal than with the tuna (P < 0.033), turkey (P < 0.001) and egg (P < 0.001) meals. Mean energy intake at the ad libitum meal was significantly lower (P < 0.001) with the whey meal than with the tuna, egg and turkey meals. There was a strong relationship between self-rated appetite, postprandial insulin response and energy intake at lunch. Whey protein meal produced a greater insulin response, reduced appetite and decreased ad libitum energy intake at a subsequent meal compared with the other protein meals, indicating a potential for appetite suppression and weight loss in overweight or obese individuals.

Reference

Br J Nutr. 2010 May 11:1-8. [Epub ahead of print] The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men.  Pal S, Ellis V. School of Public Health, Curtin Health Innovation Research Institute, ATN Centre for Metabolic Fitness, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia.

Study summary:
OBJECTIVE: We evaluated the efficacy of oral supplementation with milk whey proteins and modified starch (70%WPI:30%MS), on nutritional and functional parameters of patients with ALS. METHOD: A prospective randomized double-blind study was performed with 16 ALS patients, divided in two groups, the treatment group received (70%WPI:30%MS) and the control group received (maltodextrin). They underwent prospective nutritional and functional assessment for 4 months. RESULTS: Patients in the treatment group presented weight gain, increased body mass index (BMI), increased arm muscle area and circumference, higher albumin, white blood cell and total lymphocyte counts, and reduced creatine-kinase, aspartate aminotransferase and alanine aminotransferase. In the control group, biochemical parameters did not change, but weight and BMI declined. CONCLUSION: Our results indicate that the agglomerate 70%WPI:30%MS may be useful in the nutritional therapy of patients with ALS.

Arq Neuropsiquiatr. 2010 Apr;68(2):263-8.
Effect of nutritional supplementation with milk whey proteins in amyotrophic lateral sclerosis patients.
Silva LB, Mourão LF, Silva AA, Lima NM, Almeida SR, Franca MC Jr, Nucci A, Amaya-Farfán J.
Federal University of Alfenas, MG, Campinas SP, Brazil.

The purpose of this study was to investigate whether short-term amino acid supplementation could maintain a short-term net anabolic hormonal profile and decrease muscle cell damage during a period of high-intensity resistance training (overreaching), thereby enhancing recovery and decreasing the risk of injury and illness. Eight previously resistance trained males were randomly assigned to either a high branched chain amino acids (BCAA) or placebo group. Subjects consumed the supplement for 3 weeks before commencing a fourth week of supplementation with concomitant high-intensity total-body resistance training (overreaching) (3 x 6-8 repetitions maximum, 8 exercises). Blood was drawn prior to and after supplementation, then again after 2 and 4 days of training. Serum was analyzed for testosterone, cortisol, and creatine kinase. Serum testosterone levels were significantly higher (p < 0.001), and cortisol and creatine kinase levels were significantly lower (p < 0.001, and p = 0.004, respectively) in the BCAA group during and following resistance training. These findings suggest that short-term amino acid supplementation, which is high in BCAA, may produce a net anabolic hormonal profile while attenuating training-induced increases in muscle tissue damage. Athletes' nutrient intake, which periodically increases amino acid intake to reflect the increased need for recovery during periods of overreaching, may increase subsequent competitive performance while decreasing the risk of injury or illness.

Reference
J Strength Cond Res. 2010 Apr;24(4):1125-30.
Amino acid supplements and recovery from high-intensity resistance training.
Sharp CP, Pearson DR.
Department of Health and Human Performance, College of Charleston, Charleston, South Carolina, USA.