Recent research suggests that collagen-enriched protein bars may offer a modest boost to weight loss efforts, but the findings are far from conclusive. A 12-week study in Spain found that participants consuming two collagen bars daily lost an average of 6.6 pounds—more than double the 3.3 pounds lost by the control group, which only drank water before meals.
How Collagen Works: Beyond Skin and Joints
Collagen, the body’s most abundant protein, is traditionally known for its role in supporting skin, bones, and connective tissues. However, this study suggests a potential metabolic effect: the collagen in these bars was designed to expand in the stomach, creating a feeling of fullness. This satiating effect likely contributed to reduced calorie intake.
The bars themselves weren’t just collagen; they contained a mix of ingredients—chocolate coating, fiber, soy protein, and sweeteners—raising questions about which component drove the weight loss. One expert noted that the benefit could simply be from a low-calorie protein bar with fiber, a known weight-loss aid.
The Gut Connection: More Than Just Fullness?
Researchers hypothesize that collagen’s effect extends beyond simple satiety. Because it’s hard to digest, collagen reaches the large intestine, feeding gut bacteria and producing short-chain fatty acids linked to reduced inflammation and obesity. Some also suggest collagen might be more “thermogenic” than other proteins, meaning it burns more calories during metabolism.
Caveats and Concerns: A Small Study with Big Questions
The study’s results, though statistically significant, showed only a one-BMI-point difference between groups—a small amount for people with obesity. The 12-week timeframe is also short: long-term weight loss maintenance remains unknown.
Critically, the study was funded by Viscofan, a collagen-casing manufacturer, creating a potential bias. The collagen used wasn’t just any supplement; it was specially treated to retain water, a feature unavailable in over-the-counter products.
The Verdict: Low-Risk, Low-Certainty
Trying collagen supplements carries few risks, but replicating the study’s results is unlikely. The bars’ unique formula isn’t publicly available. For now, experts recommend sticking to tried-and-true weight loss methods while remaining open to further research. As one surgeon put it, “Obesity is an incredibly complicated disease to treat, and we use any tool we have in our toolbox.”
Ultimately, while collagen shows promise, it’s too early to rely on supplements for significant weight loss. More rigorous, long-term studies are needed before collagen can be considered a reliable solution.
