To read the full abstract: Cell Metab. 2020;31(1):92104 e5. doi: 10.1016/j.cmet.2019.11.004
Short summary: Ten-hour time-restricted eating (TRE) for 12 weeks in adults with metabolic syndrome treated with standard medical care resulted in weight loss, decreased waist circumference, and lower blood pressure and levels of cardiovascular disease-promoting lipids.
Comment: Erratic eating patterns and eating over an extended period of time during the 24-h day can disrupt circadian rhythms. Chronic circadian disruption is associated with increased risk for components of obesity, hypertension, insulin resistance, inflammation and dyslipidemia. Objective longitudinal monitoring of human eating habits over several days has found that >50% of people eat within a window of >15 h.
Time-restricted eating (TRE) is an emerging dietary intervention that aims to maintain a consistent daily cycle of feeding and fasting to support robust circadian rhythms.
In this pilot study, 19 participants (13 men), mean age 59 ± 11 years, diagnosed with the metabolic syndrome, self-reported eating during a time window >14 hours per day. Their mean baseline weight was 98 ± 20 kg and their mean BMI 33.06 ± 4.76 kg/m2. The participants received a validated app, myCircadianClock, to log their caloric intake during the 2-week baseline and 12-week intervention periods, and used continuous glucose monitors.
During the 12-week intervention, eating windows reduced by on average 28.75% (−4.35 ± 1.32 h). Despite no recommendations to change dietary quantity or quality, mean daily caloric intakes reduced by 9%±14%. This was associated with a significant reductions from baseline in body weight (−3.30 ± 3.20 kg [−3%], P =0.00028), BMI (−1.09 ± 0.97 kg/m2 [−3%], P =0.00011), and accompanied by desirable reductions in percent body fat, waist circumference and blood pressure levels. Trends were observed to improvements in fasting glucose, fasting insulin and HbA1c. Most importantly, TRE was accompanied by significant reductions in total cholesterol (−13 ± 24 mg/dl [−7%], P =0.03), and LDL-C (−12 ± 19 mg/dl [−11%], P =0.016). These changes were not explained by the changes in weight.
The high level of adherence, lack of reported adverse effects, and low dropout rates suggest that a self-selected 10-h window for TRE may be a feasible treatment option for individuals with the metabolic syndrome. Larger studies with longer follow-up are needed.