Could protein bars with added collagen help with weight loss?

Medical News Today

17-05-2025

Written by Erika Watts on May 17, 2025 — Fact checked by Amanda Ward
New research explores the potential of protein bars enriched with collagen as a weight loss aid. Jeff Wasserman/Stocksy A study conducted by Spanish researchers analyzed how effective collagen is as a weight loss aid.
The study followed two groups for 12 weeks; one group received collagen-based protein bars, and the other did not.
The group that received the collagen supplement lost twice as much weight as the control group.
More than 70% of adults in the U.S. are either overweight or have obesity. As this number continues to climb, scientists are interested in finding ways to help people lose weight.
There are many popular weight loss options, such as GLP-1 drugs, but these can be cost-prohibitive for many people.
With that in mind, researchers in the new study took a closer look at the supplement collagen. Since collagen is relatively inexpensive, the researchers wondered how people who used a collagen supplement for a 12-week period would do compared to a control group.
The results showed promise for the future of using collagen supplements as a weight-loss aid, the collagen group saw a greater improvement across multiple health metrics.
The findings of the study appear in Nutrients.
Collagen is a protein found in the connective tissue of both humans and animals. Collagen supplements are often derived from cows or pigs and are widely available in pill and powder form.
Collagen has many benefits and can be helpful for improving joint health and building muscle mass. It is also beneficial for improving skin elasticity.
The supplement is gaining attention as a potential weight loss tool, and researchers in the present study wanted to see how adding a collagen supplement to one's diet could affect weight loss.
The researchers recruited 64 adults for their study, whose BMI levels ranged from being overweight to class 1 obesity.
The participants followed a healthy diet similar to the Mediterranean diet, which focuses on whole foods such as fruits, vegetables, whole grains, healthy fats, and fish and poultry.
The test group (32 people) received a protein bar to eat in addition to their meals twice per day. The 90-calorie protein bars had 10 grams of bovine-based collagen.
The control group did not receive a placebo bar and only focused on following the dietary recommendations.
The control group consumed around 2000 calories per day while the control group consumed slightly more because of the protein bars.
The participants went to several screening appointments to provide their weight, blood pressure, blood samples, and urine and fecal samples. They also completed questionnaires about their food intake and appetite.
The study results are promising for people who want to lose weight.
Not only did the collagen group have a greater weight loss than the control group, they showed improvement in cardiometabolic health.
Participants in the collagen group lost an average of 6.6 pounds compared to the control group where participants lost an average of 3.3 pounds.
The test group saw a greater decrease in systolic blood pressure with readings reduced by 8 mm Hg on average compared to a slight rise of 0.4 mm Hg in the control group. The test group also experienced bigger reductions in waist circumference, BMI, and fatty liver index .
While muscle loss is a concern with weight loss, the participants did not have this issue. The test group had a higher fat-free mass at the end of the study.
The test group participants also reported reduced hunger and an increased feeling of being full with their protein bars.
The collagen group noticed this feeling of satiety throughout the entire study. They reported the same experience when they went to screenings at months 1, 2, and 3.
Overall, the study makes an excellent case for using collagen supplements as a cost-effective way of enhancing weight loss.
A study limitation exists in that some of the authors are affiliated with the company that produces the protein bars.
Mir Ali, MD, a board certified general surgeon, bariatric surgeon, and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center spoke with Medical News Today about the study.
'This was a good study that showed the potential benefits of protein bars with collagen,' said Ali.
Ali noted that there may be some question of whether the collagen itself was responsible for the weight loss.
'I am not certain that the effects can all be attributed to collagen as protein meal replacements are also beneficial to weight loss,' commented Ali, who said more research is needed on this.
When asked whether there are any health concerns people should have about using collagen supplements, Ali did not think most people would have anything to worry about. Possible side effects with collagen
'I am not aware of any major concern with collagen supplements; perhaps a bloating sensation as collagen swells when ingested. Patients with poor gastric motility may feel more bloating, but overall collagen appears safe.'
— Mir Ali, MD
Hector Perez, MD, lead bariatric surgeon at Renew Bariatrics, also spoke with MNT .
'It's a promising and well-structured pilot study,' said Perez. 'The randomized controlled design, use of validated tools (like DEXA), and a focus on both subjective (appetite) and objective (weight, fat-free mass, metabolic markers) outcomes are strengths.'
Perez also said collagen supplements are generally safe but did say people with kidney disease need to proceed with care. Is collagen safe for everyone?
'There's a theoretical concern about kidney strain in people with impaired renal function if high protein supplements are overused, though this study's dosage (20g/day) is moderate.'
— Hector Perez, MD
While Perez finds the study promising, he did say collagen is not a 'magic bullet.'
'I'd recommend collagen as a complement to a structured weight loss program, not as a stand-alone solution,' said Perez. 'I always stress that no supplement replaces portion control, physical activity, and sustainable dietary habits.'
Nutrition / Diet
Obesity / Weight Loss / Fitness
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