Whey Protein for Weight Loss

Whey Protein for Weight Loss

Whey Protein for Weight Loss

Whey is a rich source of proteins that is derived from milk. It is often used by athletes and fitness enthusiasts to boost their energy and increase their muscle mass. However, weight loss is another potential benefit for which many individuals are taking this dietary supplement.

How Whey Protein Works

Whey proteins contain a lot of amino acids which support lean muscle production and aid in muscle recovery. It also contains lactose, minerals, and some fat, depending on the type consumed, which help improve nutrition and strengthen the immune system. Studies have shown that aside from these important benefits whey protein may also have significant weight loss advantages and this may be explained by different mechanisms.

Whey Protein Decreases Your Appetite

Research has shown that individuals who take whey protein supplements feel full after taking it and feel less hungry after a few hours. This may be explained by the release of hormones that regulate hunger and appetite in the body, such as cholecystokinin, leptin, insulin, and other substances, which promote the feeling of satiety.1 In addition, another study has shown that the release of the hormone ghrelin, which increases appetite, is reduced by the intake of whey protein. 2

These studies suggest that individuals taking whey protein may lose pounds and inches due to changes in hormone levels controlling hunger and appetite. The result is a significant decrease in food and calorie intake.

Whey Protein Increases Insulin Sensitivity

A high amount of body fat is associated with decreased insulin sensitivity. When compared to eating red meat, it was found that whey protein is more effective in increasing insulin sensitivity and in reducing calorie intake and body fat among laboratory animals.3 This study has shown that consuming whey protein can significantly decrease blood lipid (fat) levels, decrease calorie intake and weight gain and enhance insulin sensitivity more effectively than eating red meat.

Whey Protein Enhances Fat Breakdown, Muscle Build-Up

When people take more carbohydrates as a primary energy source, they have a harder time losing significant amounts of weight. However, when proteins from whey are used as one’s source of energy, the body tends to breakdown more fat and protein to convert into glucose, which helps reduce their weight. This was shown by scientists who fed laboratory mice with glucose, whole-milk protein, or whey protein. The mice which consumed either glucose or whole milk increased their body fat while mice which consumed whey protein increased their lean muscle mass.4

Whey Protein Helps Reduce Stress Hormones

Stress has been known to increase the risk for obesity because it leads to anxiety, increased appetite and loss of sleep. These have been associated with a decrease in serotonin, a hormone which modulates mood and sleep habits, and an increase in cortisol, a stress hormone which affects mood and appetite.

Scientists have found that people who are vulnerable to stress may increase their serotonin levels and decrease their cortisol levels by consuming whey protein. Whey protein contains large amounts of alpha-lactalbumin, a whey constituent that is rich in the amino acid tryptophan. Tryptophan is a building block of serotonin, which when found at healthy levels, helps prevent anxiety, depression, and poor appetite control. A decrease in stress reduces the release of cortisol which then reduces overeating and weight gain.

Calcium in Whey Protein for Weight Management

Studies have shown that among the dietary sources of calcium, dairy products like whey provide large amounts of the mineral, which not only increases bone mass, but also decrease body fat. Calcium also plays a synergistic role with the proteins in whey, particularly the branched-chain amino acids, which help increase lean muscle mass and reduce fat and weight gain.5


  1. 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 Feb. 89(2):239-48.
  2. Goodman, B. Whey Protein May Be Helpful for Weight Loss. WebMD. 2011. http://www.webmd.com/diet/news/20110715/whey-protein-may-be-helpful-for-weight-loss
  3. Belobrajdic DP, McIntosh GH, Owens JA. A high-whey-protein diet reduces body weight gain and alters insulin sensitivity relative to red meat in wistar rats. J Nutr. 2004 Jun. 134(6):1454-8.
  4. Brink, W. How Whey Promotes Weight Loss. LEF Magazine. 2006. http://www.lef.org/magazine/mag2006/mar2006_report_whey_01.htm
  5. Zemel MB. Role of calcium and dairy products in energy partitioning and weight management. Am J Clin Nutr. 2004 May. 79(5):907S-912S.