Collagen peptides, appetite and energy intake after exercise
What it found
In 15 active women, taking 15 g of collagen peptides daily for a week led to eating about 41 kcal less at a meal after exercise, compared with a placebo.
Blood levels of some appetite hormones changed, but feelings of hunger and fullness did not.
What they found
Studies in people
Energy intake at meal
Women ate about 10% (about 41 kcal) less at the pasta meal after taking collagen peptides compared with the placebo. This difference was still there when body weight was taken into account.
Appetite feelings
There was no difference in hunger, fullness, desire to eat, or other appetite sensations between the collagen and placebo trials, either during the 6 days before exercise or on the exercise day.
Appetite hormones
After collagen peptides, blood levels of GLP-1 and insulin were higher, while ghrelin and leptin were lower, compared with placebo. PYY, CCK and blood glucose did not differ.
Gastrointestinal symptoms
There was no difference in nausea or stomach discomfort between the two trials. Headache incidence was lower in the collagen trial.
Exercise perception
During cycling, heart rate was similar between trials, but participants rated the exercise as slightly harder (higher perceived exertion) in the collagen trial.
What the authors conclude
“CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced ad libitum energy intake at a subsequent meal in physically active females.”
Also in their conclusions
- They conclude that 7 days of collagen peptide supplementation, with the final dose after exercise, increases insulin and GLP-1 and reduces energy intake at a later meal in physically active females.
- They suggest that if collagen peptides are taken after exercise for recovery, there may be a small drop in energy intake at the next meal.
- They note that the 41 kcal reduction is small and may not be clinically meaningful, and call for more research on mechanisms and longer-term effects.
How it was done
The authors wanted to see if collagen peptides, which are low in some amino acids but rich in others, could affect appetite and food intake after exercise, since most research has focused on other proteins like whey and soy.
Fifteen healthy, physically active women aged 18 to 30 took either 15 g of collagen peptides or a taste-matched placebo (water) daily for 7 days in a randomised, double-blind, cross-over trial. On day 7, they cycled for 45 minutes, then took the final supplement, and 60 minutes later ate as much pasta as they wanted. Blood was sampled and appetite ratings were recorded.
What it can’t tell you
- This study was in young, active women, so the results may not apply to men, older adults, or people with obesity.
- The study lasted only 7 days and measured one meal, so it cannot show what happens over longer periods or with different doses.
- The authors did not measure collagen-specific amino acids in the blood, so they cannot confirm how the supplement was absorbed or what exactly caused the hormone changes.
Who paid
- Authors work at
- Loughborough University, UK; University of Leicester, UK; University Hospitals of Leicester NHS Trust and University of Leicester, UK
The paper
- Title
- The effects of collagen peptide supplementation on appetite and post-exercise energy intake in females: a randomised controlled trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Reynolds KM, Hansell EJ, Thorley J, et al (2025). The effects of collagen peptide supplementation on appetite and post-exercise energy intake in females: a randomised controlled trial. The British journal of nutrition. doi:10.1017/S0007114525103851Free full textPubMed 40685650DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error