Background: There is a growing interest in intermittent fasting as a method of body fat loss. However, research on time-restricted eating, a type of intermittent fasting, is more limited. The purpose of this study was to assess the effects of time-restricted eating on fat mass in women.

Methods: 20 healthy, young (21.3 years ± 1.2 years), body mass stable (± 2.27 kg in the past 6 months) women completed a 4-week time-restricted eating study. During the intervention, participants restricted their daily food intake to an 8-hour period, i.e., between 1200 to 2000 hours. Changes in fat mass and body mass were assessed via densitometry (Bod Pod®). Hunger, satisfaction, fullness, and adherence were assessed on a weekly basis by self-report.

Results: A 0.6 kg ± 1 kg decrease in body mass occurred after the 4 weeks (p = 0.015, n = 20) but changes in fat mass were non-significant. Women who performed strength training during the study experienced a 0.7 kg ± 0.5 kg decrease in fat mass (p = 0.037, n = 5). Overall protocol adherence was high (>5.5 d/wk) throughout the intervention. Hunger, satisfaction, and fullness remained constant over the study.

Conclusions: Participants seemed to adapt to the time-restricted eating regime quickly and were able to sustain it over a 4-week period. Body mass and fat mass losses were small overall; however, some individuals responded substantially. Perhaps a longer intervention is needed to produce consistency. Time-restricted eating appears to have potential as a fat loss strategy; however, no definitive conclusions can be made regarding its effectiveness at present. More research is needed.

Digital Object Identifier

DOI: 10.5206/wurjhns.2017-18.3