Timing of food intake: Sounding the alarm about metabolic impairments? A systematic review.

Growing evidence points to an association between timing of food intake and obesity in humans, raising the question if when to eat matters as much as what and how much to eat. Based on the new definition of obesity as a chronobiological disease, an unusual or late meal timing represent a circadian chronodisruption, leading to metabolic impairments. Preliminary data from cross-sectional and experimental studies suggest that changes in meal timing can influence obesity and success of weight loss therapy, independently from total energy intake, dietary composition and estimated energy expenditure. A systematic review of observational and experimental studies in humans was conducted to explore the link between time of food ingestion, obesity and metabolic alterations. Results confirm that eating time is relevant for obesity and metabolism: observational and experimental studies found an association between meal timing, weight gain, hyperglycemia and diabetes mellitus with benefits deriving from an early intake of food in the day in a wide range of individuals. Herein clinical, future perspectives of chronoprevention and chronotherapy of obesity and type 2 diabetes are also provided. In conclusion, meal timing appears as a new potential target in weight control strategies, and therapeutic strategies should consider this contributor in the prevention of obesity.