Whey protein supplementation and weight gain
Pro Research Analysisby 
Searched over 200M research papers
Whey Protein Supplementation and Lean Body Mass Gain
Research consistently shows that whey protein supplementation, especially when combined with resistance training, leads to significant increases in lean body mass (muscle mass) compared to other protein sources like soy or carbohydrates. Studies in both non-resistance-trained adults and athletes found that those supplementing with whey protein experienced greater gains in muscle mass and strength than those consuming soy protein or carbohydrate supplements, even when total protein and calorie intake were similar 13. Whey protein’s high leucine content and rapid digestibility are key factors in its ability to stimulate muscle protein synthesis more effectively than other proteins 123.
Meta-analyses and reviews further confirm that whey protein supplementation improves body composition by increasing lean body mass, without significantly affecting overall body weight or fat mass in most adult populations 210. This effect is observed in both younger and older adults, with older men also experiencing increased muscle strength and lean mass when consuming whey protein-based supplements, especially when combined with exercise .
Whey Protein and Weight Gain: Effects on Body Weight and Fat Mass
While whey protein is effective for building muscle, its impact on overall body weight and fat mass is more nuanced. Most human studies indicate that whey protein supplementation does not significantly increase total body weight or fat mass when consumed as part of a balanced diet and exercise program 1210. In fact, in some populations, such as women who regained weight after bariatric surgery, whey protein supplementation actually promoted weight loss and fat mass reduction, while preserving lean mass .
In overweight or obese individuals, evidence is mixed. Some studies suggest that whey protein can help reduce body fat and improve satiety, but the long-term effects on body weight are still inconclusive . The quality of protein and the context of calorie intake (e.g., calorie restriction vs. ad libitum intake) play important roles in these outcomes 28.
Animal Studies: Contrasting Effects in Mice
Animal studies provide additional insights but also highlight differences compared to humans. In mice, the effects of whey protein on weight gain depend on the form of whey and the dietary context. For example, whey protein hydrolysate (WPH) exacerbated weight gain and impaired glucose metabolism in mice fed a high-fat diet, while undigested whey protein isolate (WPI) did not have these negative effects . Conversely, other studies found that whey protein isolate reduced early life weight gain and improved metabolic health in mice on a high-fat diet, compared to casein . Whey protein hydrolysates have also been shown to attenuate weight gain and improve blood lipids and glucose in obese, middle-aged mice .
Whey Protein vs. Other Proteins: Soy and Casein
When compared to other protein sources, whey protein consistently outperforms soy in promoting lean body mass gains, but does not significantly differ in its effects on total body weight or fat mass 110. Compared to casein, whey protein may reduce early weight gain and improve metabolic markers in animal models, but these effects are less clear in humans .
Conclusion
Whey protein supplementation is effective for increasing lean body mass and muscle strength, especially when combined with resistance training. It does not typically cause significant weight gain or increases in fat mass in humans, and may even support weight loss and fat mass reduction in certain populations. The effects of whey protein on body weight and fat mass are influenced by factors such as protein quality, total calorie intake, and the presence of resistance training. Animal studies show variable results, suggesting that the form of whey protein and dietary context are important considerations. Overall, whey protein is a valuable supplement for supporting muscle growth and improving body composition without promoting unwanted weight gain.
Sources and full results
Most relevant research papers on this topic
Whey Protein Supplementation During Resistance Training Augments Lean Body Mass
Whey protein supplementation during resistance training promotes greater gains in lean body mass compared to soy protein or isocaloric carbohydrate control treatments.
Supplemental protein in support of muscle mass and health: advantage whey.
Whey protein supplementation promotes muscle gains, maintains muscle mass during weight loss, and reduces muscle loss with age.
Whey protein supplementation in muscle hypertrophy
Whey protein supplementation contributes to increased muscle mass and strength in athletes with suitable training and diet, promoting muscle growth and strength gains.
Whey peptides exacerbate body weight gain and perturb systemic glucose and tissue lipid metabolism in male high-fat fed mice.
Whey protein hydrolysate (WPH) exacerbates high-fat diet-induced body weight gain and impairs glucose homeostasis, with increased inflammation, ectopic fat accumulation, and mitochondrial dysfunction.
Whey Protein Reduces Early Life Weight Gain in Mice Fed a High-Fat Diet
Whey protein initially reduces weight gain in young mice fed a high-fat diet, but the effect on weight gain ceases, it improves glucose tolerance, insulin sensitivity, and reduces plasma cholesterol.
Whey Protein Supplementation Enhances Body Fat and Weight Loss in Women Long After Bariatric Surgery: a Randomized Controlled Trial
Whey protein supplementation promotes body weight and fat loss in women with long-term weight regain after bariatric surgery.
Effects of whey protein supplementation on adiposity, body weight, and glycemic parameters: A synthesis of evidence.
Whey protein supplementation's long-term effects on maintaining muscle mass and reducing body fat in overweight individuals and those with type 2 diabetes mellitus during calorie restriction remain inconclusive.
Whey protein hydrolysates alleviated weight gain and improved muscle in middle-aged obese mice induced by a high-fat diet
Whey protein hydrolysates can help manage weight in middle-aged obese mice by reducing energy intake, attenuating weight gain, and improving blood lipids and glucose.
Comparison of the effect of soya protein and whey protein on body composition: a meta-analysis of randomised clinical trials
Whey protein supplementation significantly improves body composition by increasing lean body mass without affecting fat mass, body mass, or body fat percentage.
Try another search
steel wire rope tensile strength
vitamin b6 and energy metabolism
climate change impact on United States geography
james webb telescope observations of black holes
What is the relationship between perceived organizational support and employee engagement in remote work environments?
mullein dosage and safety