Effects of red pepper added to high-fat and high-carbohydrate meals on energy metabolism and substrate utilization in Japanese women

The effects of dietary red pepper added to high-fat (HF) and high-carbohydr ate (HC) meals on energy metabolism were examined in thirteen Japanese fema le subjects. After ingesting a standardized dinner on the previous evening, the subjects took an experimental breakfast (1883 kJ) under the following four conditions: HF meal, HF and red-pepper (10 g) meal, HC meal, or HC and red-pepper meal. Palatability of the experimental meals was measured immed iately after the meals. Expired air was collected before and for 210 min af ter the meal to determine energy expenditure and macronutrient oxidation. D iet-induced thermogenesis was significantly higher after the HC meals than after the HF meals. Lipid oxidation was significantly lower and carbohydrat e oxidation was significantly higher after the HC meals than after the HF m eals. Addition of red pepper to the experimental meals significantly increa sed diet-induced thermogenesis and lipid oxidation, particularly after the HF meal. On the other hand, carbohydrate oxidation was significantly decrea sed by the addition of red pepper to the experimental meals. Addition of re d pepper to the HC meal increased the perceived oiliness of the meal to the same level as that of the HF meals. These results indicate that red pepper increases diet-induced thermogenesis and lipid oxidation. This increase in lipid oxidation is mainly observed when foods have a HF content whereas th e increase in the perceived oiliness of the meal was found under the HC mea l conditions.