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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
92
Participants will be advised to eat only during a selected window of 8 hours over the 24-hour cycle, i.e. from 6am to 2pm, with a 1-hour allowance according to their daily routine
Participants will be advised to eat only during a selected window of 8 hours over the 24-hour cycle, i.e. from noon to 8pm, with a 1-hour allowance according to their daily routine
Participants will be advised to eat a minimum of 3 meals over the 24-hour cycle, i.e. breakfast from 6am to 9am, lunch from 11am to 2pm, dinner from 6pm to 10pm. Snacks will be allowed between meals
Geneva University Hospitals
Geneva, Switzerland
Change in body fat mass
As measured by dual-energy x-rax absorptiometry (DXA)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in physical activity
As measured by actigraphy
Time frame: From randomization visit to close-out visit (12 weeks)
Change in sleep/wake cycles
As measured by actigraphy
Time frame: From randomization visit to close-out visit (12 weeks)
Change in ambient light
As measured by actigraphy
Time frame: From randomization visit to close-out visit (12 weeks)
Change in sleep quality
As measured by the Pittsburgh Sleep Quality Index (scale 0-21, 0 indicating no sleeping difficulty, 21 indicating severe sleeping difficulties)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in eating duration
Duration from the first to last caloric intake over 24-hour cycle
Time frame: From randomization visit to close-out visit (12 weeks)
Change in calorie intake over the 24-hour cycle
Assessed by a 24-hour food recall
Time frame: From randomization visit to close-out visit (12 weeks)
Change in weight
Body weight (kg)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in waist circumference
Waist circumference (cm) assessed with a measuring tape
Time frame: From randomization visit to close-out visit (12 weeks)
Change in hip circumference
Hip circumference (cm) assessed with a measuring tape
Time frame: From randomization visit to close-out visit (12 weeks)
Change in systolic and diastolic blood pressure
As measured with an arm cuff in the sitting position
Time frame: From randomization visit to close-out visit (12 weeks)
Change in fasting glucose
As measured in clinical chemistry
Time frame: From randomization visit to close-out visit (12 weeks)
Change in lipid profile (concentration of total cholesterol, LDL cholesterol, triglycerides, HDL cholesterol)
As measured by clinical chemistry
Time frame: From randomization visit to close-out visit (12 weeks)
Change in body fat mass
As measured by bioelectrical impedance analysis (BIA)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in lean body mass
As measured by dual-energy x-rax absorptiometry (DXA)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in fat-free mass
As measured by bioelectrical impedance analysis (BIA)
Time frame: From randomization visit to close-out visit (12 weeks)
Change in resting energy expenditure
As measured by indirect calorimetry
Time frame: From randomization visit to close-out visit (12 weeks)
Change in glucose excursion
As measured by continuous glucose monitoring
Time frame: From randomization visit to close-out visit (12 weeks)
Incidence of adverse events in response to the randomized intervention
Adverse events graded after the Common Terminology Criteria for Adverse Events version 5.0
Time frame: From randomization visit to close-out visit (12 weeks)
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