Time-restricted eating has emerged as a potential strategy to achieve weight loss in subjects with obesity. It describes a practice of intermittent fasting, whereby the hours within which an individual can eat are limited across 24 hours. In some small pilot studies, time-restricted eating was associated with reduced fat mass and body weight in patients with obesity, but these studies were not adequate to support changes to clinical guidelines.

In this randomised, controlled trial, conducted in China, Liu et al. instructed 139 participants aged 18–75 (body mass index 28–45kg/m2) to follow a calorie-restricted diet, either in a time-restricted window (08.00 to 16.00) or at times chosen by the individual participants. At 12 months of follow-up, 118 participants remained. The percentage weight loss from baseline was 9.0% (8kg) in the time-restriction group, and 7.2% (6.3kg) in the calorie-restriction-only group (group difference –1.8kg, P=0.11). There was no difference between the groups in blood pressure, waist circumference or other markers of metabolic health, such as lipid levels.

The study is limited by its relatively small sample size, and by the fact that the period for eating at baseline was shorter than has been reported elsewhere (so the change incurred by restricting eating to 08.00–16.00 may not have been very great). However, the authors suggest that time-restricted eating may be a useful approach to accomplish calorie restriction without the resources required for traditional models of intentional restriction of calories. Further research is warranted to determine the generalisability of these findings.

Read the full article in New England Journal of Medicine 386 1495–1504