Effect of Time Restricted Feeding on Body Weight Metabolic Disease Risk Factors in Adults with Obesity

This study investigated the effects of time restricted feeding (TRF) on body weight, metabolic disease risk factors, sleep, and safety in adults with obesity. TRF is a form of intermittent fasting in which individuals eat all their food within a certain window of time each day, and water fast for the remaining hours of the day. Obese subjects (n = 23) participated in an 8-h time restricted feeding intervention (ad libitum feeding between 10:00 to 18:00 h, water fasting between 18:00 to 10:00 h) for 12 weeks. Results from this study show that 12 weeks of 8-h TRF decreases body weight by ~3%. Subjects were adherent to the prescribed eating window on ~6 days per week, and this level of adherence remained constant throughout the 12-week trial. Our findings also indicate that reducing the daily eating window to 8-h/d decreases caloric intake by ~300 kcal/d, without intentional calorie counting. TRF produced significant reductions in systolic blood pressure, however, other metabolic disease risk parameters (plasma lipids and glucoregulatory factors) remained unchanged. Sleep quality, timing, duration and insomnia severity remained unchanged after 12 weeks. Our results also suggest that TRF is a safe diet therapy that does not negatively affect eating disorder symptoms, eating behaviors, or measures of overall health such as resting metabolic rate and complete blood count. These preliminary data offer promise for the use of TRF as a safe weight-loss technique in adults with obesity, but longer-term, larger-scale randomized controlled trials will be required before solid conclusions can be reached.