Growing evidence points to an association between timing of eating food and body weight in humans.
For example, late lunch eaters lost less weight and displayed a slower weight-loss rate during a 20 weeks of treatment than early-eaters.
This raises the question whether when to eat matters as much as what and how much to eat.
Based on the new definition obesity is a chronobiological disease, and an unusual or late meal timing can disrupt the body clock, leading to metabolic impairments.
Previous studies suggest that changes in meal timing can influence obesity and success of weight loss therapy.
The results are independent from total energy intake, dietary composition and estimated energy expenditure.
In a recent study, scientists conducted a systematic review of observational and experimental studies in humans to explore the link between time of food ingestion, obesity and metabolic alterations.
Results confirm that eating time is relevant for obesity and metabolism: there is an association between meal timing, weight gain, and type 2 diabetes.
People can benefit from an early intake of food in the day. This is because there is an active circadian clock in body fat. Some active genes expressed in body fat follow a daily rhythmic pattern.
Thus, a specific temporal order in the daily patterns of these genes appears to be crucial for the body to exclusively either accumulate fat or to mobilize fat at the proper time.
Because feeding is the source of energy for body fat, the time of eating, particularly for high energy content meals, may be decisive in how the fat is accumulated.
Changes in this timing could have metabolic consequences for the development of obesity and perhaps for weight loss.
To summarize, meal timing appears as a new potential target in weight control strategies, and therapeutic strategies should consider this contributor in the prevention of obesity.