The capsaicin analog nonivamide decreases total energy intake from a standardized breakfast and enhances plasma serotonin levels in moderately overweight men after administered in an oral glucose tolerance test: A randomized, crossover trial

Scope: Since bolus administration of capsaicin has been shown to reduce appetite and ad libitum energy intake, this study elucidated the satiating effect of the less pungent capsaicin analog, nonivamide, on subjective feelings of hunger, ad libitum food intake, and satiating hormones in moderately overweight male subjects. Methods and results: Following a randomized, crossover design, 24 male subjects (BMI 27.5 ± 1.53 kg/m²) received either 75 g glucose in 300 mL water (control treatment, CT) or the same glucose solution supplemented with 0.15 mg nonivamide (nonivamide treatment, NT). Ratings of hunger were assessed before and 2 h after each intervention by means of visual analog scales. Ad libitum energy and macronutrient intakes from a standardized breakfast 2 h postintervention were calculated. Plasma glucose, insulin, peptide YY (3-36), glucagon-like peptide 1, and serotonin were quantified in blood samples drawn before and 15, 30, 60, 90, and 120 min after each intervention. NT reduced subjective feelings of hunger and ad libitum energy and carbohydrate intakes from a standardized breakfast compared to CT. Plasma analysis revealed higher mean plasma glucagon-like peptide 1 and serotonin concentrations after NT versus CT. Conclusion: Addition of 0.15 mg nonivamide to a glucose solution reduced ad libitum energy intake from a standardized breakfast in moderately overweight men.