This study examined whether supplementation with collagen peptides (CP) affects appetite and post-exercise energy intake in healthy active females.

In this randomised, double-blind crossover study, 15 healthy females (23 ± 3 y) consumed 15 g/day of CP or a taste matched non-energy control (CON) for 7 days. On day 7, participants cycled for 45 min at ∼55% Wmax, before consuming the final supplement. Sixty min post supplementation an ad libitum meal was provided, and energy intake recorded. Subjective appetite sensations were measured daily for 6 days (pre- and 30 min post-supplement), and pre (0 min) to 280 min post-exercise on day 7. Blood glucose and hormone concentrations (total ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), cholecystokinin (CCK), dipeptidyl peptidase-4 (sDPP4), leptin, and insulin, were measured fasted at baseline (day 0), then pre-breakfast (0 min), post-exercise (100 min), post-supplement (115, 130, 145, 160 min) and post-meal (220, 280 min) on day 7.

Ad-libitum energy intake was ∼10% (∼41kcal) lower in the CP trial (P=0.037). There was no difference in gastrointestinal symptoms or subjective appetite sensations throughout the trial (P≥0.412). Total plasma GLP-1 (area under the curve, CON: 6369±2330; CP: 9064±3021 pmol/L; P<0.001) and insulin (+80% at peak) were higher after CP (P<0.001). Plasma ghrelin and leptin were lower in CP (condition effect; P≤0.032). PYY, CCK, sDPP4 and glucose were not different between CP and placebo (P≥0.100).

CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced ad libitum energy intake at a subsequent meal in physically active females.