I have always dismissed whey protein – you know, you’ve seen those pyramids of canisters of the stuff in the windows of shops selling supplements – as a way to take money off body builders. However, recent research suggests that it helpful for people wanting to lose weight.
Whey protein is the protein contained in whey, the watery portion of milk that separates from the curds when making cheese. It is rich in amino acids and is rapidly absorbed by the body – which is why body builders like to slug it back after work outs. Whey protein has one of the highest protein digestibility-corrected amino acid scores (PDCAAS, a measure of protein bioavailability) and is more rapidly digested than other proteins, such as casein (another milk protein).
A 2009 University of Maastricht study found that it can help people maintain weight loss after a very low-calorie diet and performed much better than maltodextrin (incidentally, the main ingredient in Sensa) These results show that low-fat, high-casein or whey protein weight maintenance diets are more effective for weight control than low-fat, HC diets.
And this year, researchers concluded that consumption of a breakfast yoghurt drink with added whey or alpha-lac increased energy expenditure, protein balance and decreased fat balance compared with a NP breakfast. The alpha-lac-enriched yogurt drink suppressed hunger and the desire to eat more than the whey-enriched yogurt drink.
According to an interim report from the US Dept of Agriculture, there is a significant benefit of dietary protein supplementation with respect to body weight and fat, by preserving lean body mass and promoting fat loss. Protein intake also improves insulin response. These results suggest that dietary protein is associated with improving body composition and that whey protein may help improve some risk factors for chronic diseases. This all seemed very impressive until I discovered that the US Whey Protein Research Consortium provided funding for the study.
Having said all this, whey protein supplements are not the way to go (pun intended) for normal folks who are not either coming off a severely calorie restricted diet or are obsessively pumping iron. People who do not include dairy foods in their diets do not consume whey protein. However, the amino acids in whey protein are available from other sources, and a deficiency of these amino acids is unlikely. In fact, most Americans consume too much, rather than too little, protein.
Some benefits of whey protein have been demonstrated with as little as 20 grams per day. For athletes in training a commonly used amount is 25 grams of whey protein per day, and shouldn’t exceed 1.2 grams per 2.2 pounds body weight. Most clinical research has used similar amounts of whey protein (source)