Could capsaicinoids help to support weight management? A systematic review and meta-analysis of energy intake data

Objective: Capsaicinoids are a group of chemicals naturally occurring in chilli peppers with bioactive properties that may help to support weight management. The aim of the present study was to conduct a meta-analysis investigating the potential effects of capsaicinoids on energy intake, to clarify previous observations and form evidence-based conclusions about possible weight management roles. Methods: Medical databases (Medline, Web of Knowledge and Scopus) were systematically searched for papers. Search terms were: 'capsaicin*' or 'red pepper' or 'chilli*' or 'chili*' with 'satiety' or 'energy intake'. Of the seventy-four clinical trials identified, 10 were included, 8 of which provided results suitable to be combined in analysis (191 participants). From the studies, 19 effect sizes were extracted and analysed using MIX meta-analysis software. Results: Data analysis showed that capsaicinoid ingestion prior to a meal reduced ad libitum energy intake by 309.9 kJ (74.0 kcal) p < 0.001 during the meal. Results, however, should be viewed with some caution as heterogeneity was high (I2 = 75.7%). Study findings suggest a minimum dose of 2 mg of capsaicinoids is needed to contribute to reductions in ad libitum energy intake, which appears to be attributed to an altered preference for carbohydrate-rich foods over foods with a higher fat content. Conclusions: Meta-anlysis findings suggest that daily consumption of capsaicinoids may contribute to weight management through reductions in energy intake. Subsequently, there may be potential for capsaicinoids to be used as long-term, natural weight-loss aids. Further long-term randomised trials are now needed to investigate these effects.