Whey Protein Diet: Sculpt Your Physique
The branched chain amino acid, Leucine, signals intracellular pathways regulating amino acid oxidation and gluconeogenesis. Whey protein (100 g) contains about 24 g of BCAAs, which have been associated with improved insulin sensitivity and satiety. The high BCAA content of whey protein may make it superior for fat loss compared to other proteins, such as chicken or beef. In the Journal of Nutrition Research, researchers reported that whey protein can help reduce belly fat compared to other protein sources. Whey protein modulates several hormones that are conducive for weight loss. The researchers explained that whey protein is a potent stimulator of Gastric Inhibitory Polypeptide (GIP), also known as the glucose-dependent insulinotropic peptide. It is now believed that the function of GIP is to induce insulin secretion. Relative to that, it is known that whey protein is a strong stimulator of GIP secretagogue, possibly through bioactive peptides present in whey or formed during its digestion. The appetite suppressing effects of whey may be due in part to the rise in GIP or thru some other mechanism (i.e. mTOR).
Acute studies have reported that whey protein isolate (60 grams per day) evaluated over six months resulted in significantly lower hyperinsulinemia (less fat storage potential), lower cortisol levels (lean muscle preservation) and increased ghrelin release (satiety enhancement). A study released in Nutrition & Metabolism reported that people on whey protein supplementation lost more weight than a control group receiving maltrodextrins in conjunction with a calorie-restricted diet. Each subject was instructed to consume one supplement 20 minutes before breakfast and one supplement 20 minutes before dinner. The whey protein supplement contained 10 grams of protein per serving as a combination of intact whey protein and peptides. It also contained minerals that were purified from milk. The control group received an isocaloric beverage containing maltodextrin. After 12 weeks, weight loss was consistently higher in the whey protein subjects, primarily the result of losing body fat (subjects taking whey protein lost 6.1 percent of their body fat mass). The whey protein group subjects also lost significantly less lean muscle mass compared to control subjects. Whey protein may be the perfect fat-loss supplement when dieting for an important event or for targeting fat loss while maintaining lean muscle1. Since whey is nutrient dense but relatively low in energy (~4 kcal/g), supplementation is an efficient method to promote skeletal muscle anabolism while promoting catabolism in fat cells and therefore is hypothesized to improve both muscle growth and fat loss.
Researchers published in Nutrition Research that whey protein can tended to reduce belly and leg fat compared to other proteins. In the study, researchers had subject’s either consume a mixed protein diet or a diet consisting of whey protein. The 2 high-protein diets contained 30% energy from protein and 40% energy from carbohydrate compared with the control diet, which contained 15% energy from protein and 55% energy from carbohydrate. The whey protein diet contained the same quantity of protein by mass as the mixed protein diet, but the entire increase of protein above the level came from the addition of a commercial whey protein isolate. The subjects dieted for eight weeks and at the end of the study although there was no statistical difference between the mixed protein and whey protein group, the whey protein-consuming group tended to have greater weight loss and fat loss. So what this means to me is that although that was not a large effect, the whey protein consuming group had a small effect for lower fat mass and weight loss.
-Frestedt JL, Zenk JL, Kuskowski MA, Ward LS, Bastian ED. A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study. Nutr Metab, (Lond). 2008 Mar 27;5:8.
-Aldrich ND, Reicks MM, Sibley SD, Redmon JB, Thomas W, Raatz SK. Varying protein source and quantity do not significantly improve weight loss, fat loss, or satiety in reduced energy diets among midlife adults. Nutr Res. 2011 Feb;31(2):104-12.
-Layman DK, Baum JI. Dietary protein impact on glycemic control during weight loss. J Nutr 2004;134:968S-73S.
-Cribb PJUS. Whey proteins in sports nutrition. Applications monograph sports nutrition. US Dairy Exp Counc 2005;4:1-12.
-Nilsson M, Holst JJ, Bjorck IM. Metabolic effects of amino acid mixtures and whey protein in healthy subjects: studies using glucose equivalent drinks. Am J Clin Nutr 2007;85:996-1004.