Amin A, Liu Z, Franco‐Becker G, et al. - Researchers determined how L‐phenylalanine could impact gastroenteropancreatic hormone release, glucose concentrations, subjective appetite and energy intake in humans. They also investigated if these impacts were stereoisomer‐specific by comparing them with D‐phenylalanine. For this purpose, a dose‐finding, non‐randomized, unblinded, crossover study as well as an acute, randomized, double‐blind, placebo‐controlled crossover study was performed. Good tolerability of L‐phenylalanine was evident and it rose insulin as well as glucagon levels before meal ingestion at several time points vs placebo and D‐phenylalanine. L‐phenylalanine also resulted in rise in glucose‐dependent insulinotropic polypeptide [GIP] levels vs D‐phenylalanine and placebo 70 minutes post-ingestion. Overall, findings revealed that insulin, glucagon and GIP levels were increased by ingestion of L‐phenylalanine, but not D‐phenylalanine, with no marked impact on appetite.