Chronobiological evaluation and an intervention study on timing of food intake in the treatment of obesity.

Background: The chronotype of patients who cannot reach their ideal weight despite diet and exercise may play a role in this resistance. In this study, the relationship between BMI and chronobiological preferences was examined and a weight loss programme was applied to refractory obese patients with evening type (ET).

Methods: The study included 50 obese (BMI ≥ 30 kg/m2 ), 50 overweight (BMI = 25-29 kg/m2 ) and 50 normal weight (BMI < 25 kg/m2 ). The patients were asked to fill out a questionnaire including questions about sociodemographic characteristics, breakfast and night eating habits, as well as the morningness-eveningness quastionnaire (MEQ). In the second stage of the study, awareness interviews were held with ET obese patients in terms of eating time and habits.

Results: A statistically significant difference was observed between the BMI averages and the MEQ scores of ET, intermediate type (IT) and morning type (MT) groups (P = .0001). There was a statistically significant difference between the ET, IT and MT groups in terms of the distribution of late-night eating habits (P = .0001). The habit of skipping breakfast and taking more calories at dinner was found to be high in the ET patients (respectively; P = .021, P < .001). According to the results of the 3-month follow-up and intervention, the ET patients lost an average of 9.07±4.30 kg and a significant decrease was observed in the BMI scores (P < .001).

Conclusions: The study results support the idea that an individualised weight loss programme according to the patient's chronotype preferences may increase the success rate of obesity treatment. A weight loss programme that includes the timing of food intake and regulation of eating habits in evening-type obese patients can be used in the treatment of obesity.