Randomized Controlled Trial: Effects of a Bitter-Tasting Pea Protein Hydrolysate Intervention With Low Degree of Hydrolyzation on Energy Intake in Moderately Overweight Male Subjects

Optimizing plant-based protein intake, such as pea protein hydrolysates (PPHs), may aid in obesity management. This study investigated whether PPHs with varying bitterness and degrees of hydrolysis (DH) differently affect satiety in healthy male participants. In a short-term randomized control trial, 19 moderately overweight men (BMI 25–30 kg/m ²) consumed boluses of 75 g glucose plus 15 g PPH (control without PPH; PPH1: less bitter, DH = 35%; PPH2: more bitter, DH = 23%). Upon PPH administration, energy intake from an ad libitum breakfast was reduced by −126 ± 329 kcal (p < 0.05) in the PPH2 group compared to the control. PPH1 decreased plasma ghrelin and DPP-4 levels (AUC: −9.4 ± 19.6 and −12.5 ± 24.7, p < 0.05). Gastric emptying was delayed by a mean of 65% (p < 0.0001) after PPH2 consumption, assessed via ¹³C-Na-acetate breath test. Bitterness and DH of PPH influence satiety signals differently. PPH1 (less bitter, higher DH) reduces DPP-4 and ghrelin levels, promoting satiety. PPH2 (more bitter, lower DH) delays gastric emptying, enhancing satiation. These findings highlight the potential of PPHs as functional ingredients in weight management strategies.