Location: Boston, MassachusettsTitle: Timing of food intake predicts weight loss effectiveness) Author
Submitted to: International Journal of Obesity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2012
Publication Date: 1/29/2013
Citation: Garaulet, M., Gomez-Abellan, P., Alburquerque-Bejar, J.J., Lee, Y., Ordovas, J.M., Scheer, F.A. 2013. Timing of food intake predicts weight loss effectiveness. International Journal of Obesity. 37:604-611. Interpretive Summary: The relation between nutrition and health may involve not only what we eat but also when we eat it. In this regard, it has been shown already, mostly in animals, that the timing of feeding is important for weight regulation. However, this important and practical health-related issue has been less explored in humans. Moreover, given the relative lack of long-term success associated with diet-induced weight loss, it will be important to learn whether the time of food intake may contribute to the success of dietary programs aimed at normalizing body weight. Therefore, our objective was to evaluate the role of food timing in weight-loss effectiveness in a sample of 420 Mediterranean subjects who followed a 20-week weight-loss treatment program. The participants, half of them women and with an average body mass index in the obese range were grouped in early eaters and late eaters, according to the timing of the main meal consumed (lunch in this Mediterranean population). Half of the subjects were early eaters and half were late eaters (lunch time before and after 3:00 pm, respectively). Our results show that late lunch eaters lost less weight and displayed a slower weight-loss rate during the treatment than early eaters. This was achieved despite the fact that energy intake and expenditure, dietary composition, appetite hormones and sleep duration were similar between both groups. Interestingly, late eaters were more evening types, the quality of their breakfasts was poorer and skipped breakfast more frequently than early eaters. The form of the CLOCK gene (defined by a variant in the DNA sequence known as rs4580704) was associated with the timing of the main meal with a higher frequency of subjects carrying the minor allele (C) being late eaters. Therefore, our results show that eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution (as is classically done) but also the timing of food intake.
Technical Abstract: There is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown. To evaluate the role of food timing in weight-loss effectiveness in a sample of 420 individuals who followed a 20-week weight-loss treatment. Participants (49.5% female subjects; age (mean +/- s.d.): 42 +/- 11 years; BMI: 31.4 +/- 5.4 kg m(-2)) were grouped in early eaters and late eaters, according to the timing of the main meal (lunch in this Mediterranean population). 51% of the subjects were early eaters and 49% were late eaters (lunch time before and after 1500 hours, respectively), energy intake and expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied. Late lunch eaters lost less weight and displayed a slower weight-loss rate during the 20 weeks of treatment than early eaters (P=0.002). Surprisingly, energy intake, dietary composition, estimated energy expenditure, appetite hormones and sleep duration was similar between both groups. Nevertheless, late eaters were more evening types, had less energetic breakfasts and skipped breakfast more frequently that early eaters (all; P<0.05). CLOCK rs4580704 single nucleotide polymorphism (SNP) associated with the timing of the main meal (P=0.015) with a higher frequency of minor allele (C) carriers among the late eaters (P=0.041). Neither sleep duration, nor CLOCK SNPs or morning/evening chronotype was independently associated with weight loss (all; P>0.05). Eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution-as is classically done-but also the timing of food.