Endocrine Abstracts

Background: Animal-derived protein consumption has been rising globally, driven by socioeconomic factors and shifts in dietary patterns to improve performance and support weight loss. In recent years an increasing trend has been observed for plant-based proteins due to sustainability concerns. Previous studies indicate that the metabolic effects of proteins may vary according to their origin. Thus, the aim of this single-blind, crossover study was to assess the acute effects of two high-purity, plant-based protein isolates (potato – PP and rice - RP) on the peptide hormones GLP-1 and insulin in nine male participants aged 30.8 ± 9.3 years.

Methods: Participants consumed equal volumes of protein shakes with matched energy and protein content following a 12h overnight fast, with at least a week washout between visits. Peptide hormones were assessed at baseline and 30-, 60-, 120- and 180-min following shake consumption.

Results: Insulin levels at 30 min were significantly higher with RP vs PP (64.4 ± 20.9 pmol/l; P=0.046). Additionally, GLP-1 levels remained significantly lower with PP at 60, 120 and 180 min (P=0.003, P=0.001 and P=0.001, respectively). However, Pearson’s correlation coefficient revealed significant positive correlations with PP between GLP-1 (30 min) vs insulin (120min) (r=0.786, P=0.036) and GLP-1 (120 min) vs insulin (120min) (r=0.809, P=0.028), whereas there was no significant correlation between GLP-1 and insulin at any time point with RP.

Conclusion: These data show that in the case of RP, the increase in GLP-1 did not induce insulin release, suggesting a potential incretin effect independent of insulin release. Although targeted population studies with increased sample size are required alongside assessing further non-animal protein sources, our results suggest that RP may be better suited for groups at risk of beta-cell dysfunction.