Protein shakes and weight gain
Pro Research Analysisby 
Searched over 200M research papers
Protein Shakes and Weight Gain: Effects on Weight Management
Protein Shakes and Weight Loss in Overweight and Obese Adults
Multiple studies show that consuming protein shakes, especially those high in protein and fiber, can help with weight loss rather than weight gain in overweight and obese adults. When used as part of a calorie-restricted diet, high-protein, high-fiber shakes led to greater weight loss and improved metabolic markers compared to low-protein shakes or placebos. For example, participants who consumed these shakes before meals lost more weight and had better cholesterol profiles than those who consumed lower-protein shakes, even when both groups reduced their calorie intake by the same amount 13. Another study found that combining protein-enriched meal replacement shakes with moderate exercise resulted in greater reductions in body weight and body fat compared to exercise alone .
Protein Shakes and Satiety: Reducing Hunger and Calorie Intake
Protein shakes can increase feelings of fullness and reduce hunger for several hours after consumption. This effect can help people eat less overall, supporting weight loss or weight maintenance goals. In one study, participants who drank a high-protein, high-fiber shake reported feeling fuller for longer compared to those who drank a low-protein shake, which may help prevent overeating . This satiety effect is a key reason why protein shakes are often included in weight management programs .
Protein Shakes and Muscle Mass: Supporting Lean Body Mass
Increasing protein intake, especially when combined with resistance exercise, can help preserve or increase lean body mass (muscle) during weight loss. Meta-analyses show that higher daily protein intake leads to small but significant gains in muscle mass and strength, particularly in people who exercise regularly . For people undergoing significant weight loss, such as after bariatric surgery, protein shakes can help maintain muscle mass while losing fat . However, simply increasing protein intake without exercise does not lead to significant changes in muscle function or body composition in older adults .
Protein Shakes and Weight Gain: When Do They Cause Weight Gain?
Protein shakes themselves do not inherently cause weight gain unless they are consumed in excess of daily calorie needs. If someone adds protein shakes to their diet without reducing calories elsewhere or increasing physical activity, the extra calories can contribute to weight gain. However, most research shows that when used as meal replacements or as part of a calorie-controlled diet, protein shakes are more likely to support weight loss or maintenance rather than weight gain 1310. There is no strong evidence that protein shakes alone, without excess calorie intake, lead to increased fat mass in healthy adults .
Protein Shakes and Muscle-Building Behaviors in Youth
Among adolescents and young adults, protein shake use is common as part of muscle-building behaviors. However, early use of protein shakes may be linked to later use of other muscle-building substances, some of which may be harmful. This highlights the importance of monitoring supplement use in younger populations .
Conclusion
Protein shakes, especially those high in protein and fiber, are effective tools for weight loss and weight management when used as part of a calorie-controlled diet. They help increase satiety, preserve muscle mass during weight loss, and improve metabolic health markers. Protein shakes do not cause weight gain unless they contribute to a calorie surplus. For most people, especially those aiming to lose weight or maintain muscle, protein shakes are more likely to help with weight loss than weight gain.
Sources and full results
Most relevant research papers on this topic