The effects of collagen peptide supplementation on appetite and post-exercise energy intake in females: a randomised controlled trial

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 cross-over study, fifteen healthy females (23 (sd 3) years) consumed 15 g/d of CP or a taste matched non-energy control (CON) for 7 d. On day 7, participants cycled for 45 min at ∼55 % W_max, before consuming the final supplement. Sixty-min post supplementation an <i>ad libitum</i> meal was provided, and energy intake recorded. Subjective appetite sensations were measured daily for 6 d (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 (sDPP-4), 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. <i>Ad libitum</i> energy intake was ∼10 % (∼41 kcal) lower in the CP trial (<i>P</i> = 0·037). There was no difference in gastrointestinal symptoms or subjective appetite sensations throughout the trial (<i>P</i> ≥ 0·412). Total plasma GLP-1 (AUC, CON: 6369 (sd 2330); CP: 9064 (sd 3021) pmol/l; <i>P</i> < 0·001) and insulin (+80 % at peak) were higher after CP (<i>P</i> < 0·001). Plasma ghrelin and leptin were lower in CP (condition effect; <i>P</i> ≤ 0·032). PYY, CCK and glucose were not different between CP and placebo (<i>P</i> ≥ 0·100). CP supplementation following exercise increased GLP-1 and insulin concentrations and reduced <i>ad libitum</i> energy intake at a subsequent meal in physically active females.