Whey protein

2013-10-01

A well-balanced diet with appropriate amount of protein foods such as meat, eggs, dairy, and legumes can offer us all essential amino acids, and perhaps even more such as iron, zinc and vitamins to maintain our health.

Whey protein powder and its related products are everywhere nowadays.  While you may even come across it as you walk pass the “health product” aisle in supermarket, you may not know how important it is for athletes (or at least what it is for).  So what exactly is it and is there any purpose of it?

What is it?

Whey protein (20%), together with casein protein (80%), makes up the protein content of cow’s milk.  Both proteins are of excellent biological values because they contain all human essential amino acids, which cannot be made by our body.  One of the advantages of whey over casein protein is that it is more easily digested and absorbed.  This advantage perhaps explains why breastfeeding is recommended for infant as human breastmilk consist of 60% of whey protein, compared to cow’s milk.

Weight management

Some evidence suggests that whey protein as well as other types of protein may contribute to satiety due to its impact on appetite regulatory hormones.  The difference is the time they come effective.  As whey protein is rapidly absorbed, satiety can come in 30 minutes whereas casein comes after few hours.  Not to mention its great biological value in maintaining our muscle mass to keep us metabolically active, it may sound a food deal for weight management.  Yet, there isn’t prominent evidence supporting that it is particularly effective over other types.

Muscle mass gain

Athletes as well as body builders often use whey protein products, in conjunction with weight resistant training, to boost the muscle mass.  Research also backs this regime as adequate whey protein or other good quality of protein can help in body protein synthesis and repair.  Meanwhile, no matter what types of protein it is, a balanced diet including adequate energy, dietary carbohydrates, fats as well as vitamins and minerals forms the basis of muscle mass gain in which the process requires other nutrients, not only protein, to carry out the action as well as maintain normal body function.  It is also noteworthy that whey protein is not the magic pill to boost muscle mass as we can capture ample amount of protein with all the essential amino acids via various source of foods in our diets.

Be aware of the usage!

Provided that an averaged adult should consume 0.8g per kg body weight, exceeding this recommendation by consuming too much of whey or any other source of protein can lead to headache and dehydration.  Since excessive protein consumption can potentially pose damage to liver and kidney functions, people with renal disease or gout should pay special attention upon usage.

In a word, a well-balanced diet with appropriate amount of protein food such as meat, eggs, dairy and legumes can offer us all essential amino acids, and perhaps even more such as iron, zinc and vitamins to maintain our health.  Seeking for medical or dietetic advice is recommended upon usage especially for those on vegetarian diet, with diseases subjected to nutrient malabsorption, and higher protein requirement such as burns, muscle atrophy and post-surgery.

References:

1. Bendtsen, Janne K. Lorenzen, Nathalie T. Bendsen, Charlotte Rasmussen, and Arne Astrup. Effect of Dairy Proteins on Appetite, Energy Expenditure, Body Weight, and Composition: a Review of the Evidence from Controlled Clinical Trials. Adv Nutr 2013.,4:418-438

2. Gilbert J-A, Bendsen NT, Tremblay A, Astrup A. Effect of proteins from different sources on body composition. Nutr Metab Cardiovasc Dis. 2011;10(Suppl 2):B16-31.

3. Souza GT, Lira FS, Rosa Neto JC, et al. Dietary whey protein lessens several risk factors for metabolic diseases: a review. Lipids Health Dis. 2012;11:67. Doi:10.1186/1476-511X-11-67.

330 Tips provided by:  Ms Grace Lam  (Senior Dietitian - Centre for Nutritional Studies, School of Public Health and Primary Care, Faculty of Medicine, CUHK)