Can Whey Protein Make You Gain Weight If You Are Dieting?

Dieting involves a calorie deficit through dietary caloric restriction, increased caloric expenditure, or a combination of both to experience weight loss. Marketdata Enterprises reports 75 million people are on a diet in an industry that earned $60.9 billion in 2010. Many diet plans and supplements are available to promote weight loss. One such supplement is whey protein.

Sources and Functions of Whey Protein

Whey protein is naturally found in many foods, including cheese, yogurt and milk. It is also the protein source in many nutrition bars, such as Detour and Nutrilite, and is available in supplement form, usually as a powder. Whey protein is considered a high-quality protein and is widely used to increase muscular strength and improve body composition, according to the Mayo Clinic.

Whey Protein and Reduced Appetite

Whey protein has been linked to a reduced appetite and reduced overall energy intake in both lean and overweight people. According to a study published in a 2009 issue of "Physiology & Behavior," subjects reported a reduction in food consumption and appetite-regulating hormones after consuming a breakfast consisting of high whey protein. This suggests a benefit of whey protein while dieting.

Improved Body Composition

Another goal of dieting is to reduce body fat to improve body composition. Including whey protein in the diet has been linked to reduced body fat. In a 2008 study published in "Nutrition & Metabolism," subjects who consumed a reduced calorie diet while taking a whey protein supplement exhibited a significant reduction in body fat mass. Whey protein appears to increase burning fat for energy.

Weight Gain

If you exceed your daily caloric requirements, any additional calories consumed will be converted to fat and stored. Whether the extra calories come from carbohydrates, fat or protein, it does not matter as weight gain will occur. Assuming total calories are monitored and controlled, whey protein will not cause weight gain while dieting. Before starting any supplements, speak with your doctor or a dietitian.