An Effectiveness Study of Early or Late Time-Restricted Feeding on Body Composition – Pilot Study

Abstract

Abstract Objectives Our objective was to measure the differences in body composition change following a 6-week early or late time-restricted feeding without specific calorie-targets in healthy but sedentary free-living individuals with overweight/obesity. Methods Sedentary, healthy individuals with a body mass index (BMI) of more than 25 kg/m2 were recruited for a 6-week intervention. They were randomized to morning fasters (MF) who ate only between 12 pm to 8 pm, evening fasters EF who ate only between 7 am and 3 pm; and the control group, which was instructed to continue their usual pattern of eating. Specific calorie targets were not provided to all participants. Pre- and post-intervention height and weight were measured, and body composition was assessed using the dual-energy x-ray absorptiometry scanner. Intention to treat analysis was performed, using the last observation carried forward. Normality was assessed. Between-group differences in change of body composition and within-group differences for pre- and post-measurements were studied using parametric and non-parametric tests accordingly, and Bonferroni correction for multiple testing was applied. Results 10, 8, and 10 participants were in the MF, EF, and control groups, respectively. There were 11 males and 17 females. The mean age of our participants was 30.25 (SD = 10.99) years and mean BMI was 29.06 (SD = 3.63)kg/m2. There was no difference in baseline age, BMI, body fat %, total body fat mass, total lean mass and visceral fat between the 3 groups (P > 0.05). Compliance was significantly lower in evening fasters than controls (P = 0.029). Unlike MF, EF had a greater reduction in body fat mass than the controls, but the difference was non-significant (P = 0.053). There were no significant differences in body composition pre-vs post measurements within each study group (P > 0.05). Conclusions When specific calorie targets were not provided, morning fasting and evening fasting did not result in a significant change in body composition in sedentary adults with overweight/obesity in our pilot study. A larger-scale study is needed to validate these findings. Funding Sources Startup funds from Texas Tech University.