What is it?
Whey protein is a mixture of some of the proteins naturally found in milk. The major proteins found in whey protein include beta-lactoglobulin and alpha-lactalbumin. 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). 1
Where is it found?
During the process of making milk into cheese, whey protein is separated from the milk. This whey protein is then incorporated into ice cream, bread, canned soup, infant formulas, and other food products. Supplements containing whey protein are also available.
Why do dieters use it?*
Some dieters say that whey protein
- serves as another protein choice in their diets.
What do the advocates say?*
- All types of protein, including whey, provide the body with amino acids.
- Choosing whey protein over other types of protein adds variety to the protein choices available.
- Whey is a common ingredient in many meal replacements, which are designed to provide a large amount of nutrients in a minimal amount of calories.
How much is usually taken by dieters?
Whey protein may aid weight loss due to its effect on appetite. In a preliminary study, people were given 48 grams of either whey protein or milk protein (casein). Whey consumption resulted in more hunger satisfaction and reduced the amount of food eaten 90 minutes later compared with casein consumption.2 However, a double-blind study found that men taking 1.5 grams per 2.2 lbs body weight per day of whey protein for 12 weeks along with a low-calorie diet and a strength training exercise program lost the same amount of weight and body fat as did a control group that followed a similar program, but took a casein supplement instead of whey protein.3
Are there any side effects or interactions?
People who are allergic to dairy products could react to whey protein and should, therefore, avoid it.4 As with protein in general, long-term, excessive intake may be associated with deteriorating kidney function and possibly osteoporosis. However, neither kidney nor bone problems have been directly associated with consumption of whey protein, and the other dietary sources of protein typically contribute more protein to the diet than does whey protein. The possibility that certain proteins in milk may contribute to the development of diabetes in children is controversial. But since whey proteins include some of the same milk proteins, people who are avoiding milk because of concerns about the risk of diabetes should not consume whey protein either.
*Dieters and weight-management advocates may claim benefits for whey protein based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles on whey protein. For more complete and detailed information, including references and safety information, see Whey Protein as a nutritional supplement.
References
1. Dangin M, Boirie Y, Guillet C, Beaufrere B. Influence of the protein digestion rate on protein turnover in young and elderly subjects. J Nutr 2002;132:3228S–33S [review].
2. Hall WL, Millward DJ, Long SJ, Morgan LM. Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion and appetite. Br J Nutr 2003;89:239–48.
3. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab 2000;44:21–9.
4. Wal JM. Cow's milk proteins/allergens. Ann Allergy Asthma Immunol 2002;89(6 Suppl 1):3–10.
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2006-09-07
