Differential roles of breakfast only (one meal per day) and a bigger breakfast with a small dinner (two meals per day) in mice fed a high-fat diet with regard to induced obesity and lipid metabolism

BACKGROUND: Recent studies on humans and rodents have suggested that the timing of food intake plays an important role in circadian regulation and metabolic health. Consumption of high-fat foods during the inactive period or at the end of the awake period results in weight gain and metabolic syndrome in rodents. However, the distinct effects of breakfast size and the breakfast/dinner size ratio on metabolic health have not yet been fully examined in mice. METHODS: We examined whether the parameters of metabolic syndrome were differentially affected in mice that consumed a large meal at the beginning of the awake period (breakfast; one meal group) and a relatively smaller meal at end of the awake period (dinner; two meals group). The mice of each group were provided equal food volume per day. RESULTS: Mice on one meal exhibited an increase in body weight gain, hyperinsulinemia, hyperleptinemia, and a decrease of gene expression associated with β-oxidation in adipose tissue and liver compared with those on two meals. The circadian expression pattern of the Clock gene in mice on one meal was disturbed compared with those on two meals. CONCLUSIONS: In conclusion, a bigger breakfast with a smaller dinner (two meals per day) but not breakfast only (one meal per day) helps control body weight and fat accumulation in mice on a high-fat meals schedule. The findings of this study suggest that dietary recommendations for weight reduction and/or maintenance should include information on the timing and quantity of dietary intake.