Time-restricted Eating to Improve Body Fat Mass in Overweight and Obese Individuals with Morning Chronotype: a Randomized, Open-label, Multi-arm Trial

Overweight and obesity are highly prevalent conditions worldwide, despite active research of new interventions over decades. Current interventions include medications or bariatric surgery, but these approaches cannot be used in all patients and require clear indications and a close multidisciplinary management. Therefore most patients and physicians rely on lifestyle interventions, focusing on a balanced diet and physical exercise.

Recent studies have uncovered that energy metabolism is also regulated by circadian rhythms, which depend on spontaneous diurnal oscillations of the central clock, retinal sensing of ambient light, and daily feeding-fasting cycles. The chronotype has an influence on behavioral patterns, where some people describe that they are more alert in the morning or in the evening: The morning or evening chronotypes, respectively. However, in modern societies, many people are exposed to external cues in misalignment with their circadians clocks. The mismatch between the individual chronotype and the social/work life can lead to metabolic disorders.

Time-restricted eating (TRE), i.e. energy intake limited to certain windows of time without restricting calories, is an appealing approach because it proposes to realign the circadian clocks with external cues provided by the timing of food intake, thus leading to better metabolic outcomes.

The investigators speculate that the TRE intervention needs to be personalized to reach efficacy in a broader population. To tailor the TRE intervention to each individual and harmonize their eating patterns in accordance to their chronotype, the investigators plan to test early TRE vs. late TRE vs. active control in overweight and obese individuals with morning chronotype.