Pea, Faba Bean, and Whey Protein Isolates Elicit Comparable Acute Somatotropic Responses in Healthy Women: A Randomised Controlled Trial

Abstract Global challenges highlight the importance of increasing plant-based proteins in our diet, yet their effect on anabolic metabolism and the somatotropic axis remain underexplored. In this randomised, double-blind, crossover, placebo-controlled intervention study, healthy females (n = 16, age: 28 (21–38) years, body mass index: 23 (22–24) kg/m2; results expressed as median (interquartile range)) consumed 0.6 g protein/kg total body weight from pea, faba bean, and whey protein isolate dissolved in 400 ml water and a placebo (400 ml water). Postprandial growth hormone, insulin, glucose, and amino acid responses were measured in blood over 3 hr. Despite amino acid composition differences among protein sources, growth hormone secretion did not differ significantly. While the small sample size restricts definitive conclusions regarding differential effects, our findings suggest no physiologically meaningful differences between the proteins in this study. Nevertheless, these findings should be interpreted as preliminary and warrant confirmation in larger cohorts.