McCormick Science Institute

Capsaicin, Fullness & Energy Expenditure

Smeets AJ, Janssens PL, Westerterp-Plantenga MS


MSI Team

April 2013-- Researchers in the Netherlands investigated the 24 hour effect of protein and capsaicin, singly or combined, on fullness and EE during 20% energy intake restriction. Link to the paper


This single-blind, randomized, crossover design investigated whether an 80% energy requirement diet consisting of partly replacing carbohydrate by protein plus the addition of capsaicin reached the same level of fullness ratings and EE as a 100% energy requirement control diet.


Twenty-four healthy participants underwent eight 36-h sessions in a respiration chamber. The participants were fed 100 or 80% of their daily energy requirements. There were 2 control (C) conditions: 100%C and 80%C; 2 conditions with capsaicin (Caps): 100%Caps and 80%Caps; 2 conditions with elevated protein (P): 100%P and 80%P; and 2 conditions with a mixture of protein and capsaicin (PCaps): 100%PCaps and 80%PCaps. The study had a randomized crossover design with 8 randomly sequenced conditions. The participants were fed 100 or 80% of their daily energy requirements. Appetite profile, energy expenditure, and substrate oxidation were monitored. Participant gender was equally divided between males and females with BMI measurements of 25.2 +/- 0.4 kg/m2; an age range of 27 +/- 4 years and body fat of 25.6 +/- 5.7%. Participant eating behavior was assessed using a validated Dutch translation of the Three Factor Eating Questionnaire (TFEQ). Those selected for the study indicated low levels of cognitive restraint, disinhibition, and general hunger.


Compared with 100%C, the 80%C group experienced negative energy-balance effects with respect to total EE, diet-induced thermogenesis, and fullness, whereas the 80%Caps diet counteracted these effects, and the 80%P and 80% PCaps diets exceeded these effects (P < 0.01). In energy balance and negative energy balance, fat balance was more negative in the 80%Caps, P, and PCaps groups than in the 80%C group (P < 0.05) and respiratory quotient values were lower. A negative protein balance was prevented with the 80%P and 80%PCaps diets compared with the 80%C diet.


Results suggest that protein and capsaicin, consumed singly or mixed, counteracted the energy intake restriction effects on fullness and EE. During energy restriction, protein and capsaicin promoted a negative fat balance and protein treatments also prevented a negative protein balance


Smeets AJ, Janssens PL and Westerterp-Plantenga MS. Addition of capsaicin and exchange of carbohydrate with protein counteract energy intake restriction effects on fullness and energy expenditure. J Nutr. 2013 Apr;143(4):442-7. Link to the paper

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