The Effect of the Rice Endosperm Protein Hydrolysate B on Appetite in Healthy Japanese Subjects: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Rice endosperm protein hydrolysate B (REPH-B) is produced by enzymatic degradation of rice endosperm protein. REPH-B contains the following peptides: QAFEPIRSV, pEAFEPIRSV, and TNPWHSPRQGSF. A previous study reported that REPH-B has the ability to induce plasma acylated ghrelin secretion and increase food intake in animal models. In this study, we investigated the effect of REPH-B on appetite in healthy adults aged over 40 y who had a relatively low visual analogue scale (VAS) score for hunger. Forty-six healthy subjects who were aware that their appetite had decreased were enrolled. Subjects were randomly allocated to one of two groups. The influence of REPH-B on appetite was evaluated by VAS under two conditions: repeated intake over 2 wk (Study 1) and single intake (Study 2). Though a single intake of REPH-B had no influence on any of the parameters evaluated, repeated intake of REPH-B significantly improved the VAS score for hunger. In conclusion, repeated intake of REPH-B might increase hunger in healthy adults who suffer from a lack of appetite. This study was registered with UMIN Clinical Trials Registry as UMIN000049108.