A new randomized controlled trial has shed light on the benefits of time-restricted eating (TRE), suggesting that intermittent fasting may help individuals lose weight and improve metabolic markers — even without drastic changes to diet quality. Published in the Nature, the study compared the effects of an 8-hour time-restricted eating schedule to a traditional calorie-restriction diet over a yearlong period, with promising results for those seeking a more flexible approach to weight loss.
The trial included 90 adults with obesity, who were randomly assigned to one of three groups: time-restricted eating (eating only between noon and 8 p.m. without calorie counting), calorie restriction (aiming for a 25% reduction in daily intake), or a control group with no dietary changes. All participants received support via counseling and regular check-ins. By the end of the 12-month study, those in the time-restricted eating group lost an average of 10 pounds — nearly double the 5.5 pounds lost by participants in the calorie-restriction group.
Beyond weight loss, the study revealed improvements in body fat percentage and fasting insulin levels in the TRE group. This indicates not just a cosmetic change, but a significant metabolic benefit. Notably, the participants were able to adhere to the 8-hour eating window relatively well, even without prescribed calorie tracking.
The researchers emphasized that time-restricted eating may help regulate internal metabolic rhythms by consolidating food intake into a consistent daily pattern. This could support improved insulin sensitivity, reduced inflammation, and better lipid profiles. While calorie restriction also yielded benefits, the TRE group's improvements were achieved without the daily stress of measuring and limiting food — an appealing outcome for those seeking sustainable lifestyle changes.
What makes this study particularly noteworthy is the flexibility it reveals about the timing of the eating window. Previous research had often focused on early time-restricted eating (e.g., eating between 7 a.m. and 3 p.m.) based on circadian biology. However, this study centered the window from noon to 8 p.m., aligning more easily with typical social schedules and cultural norms. “A key point of this study is that the timing of the 8-hour eating window may not be as critical as previously thought, suggesting flexibility in implementation,” says Jonatan Ruiz, PhD, of the University of Granada, Granada, Spain, and the Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition in Madrid, Spain.
The trial offers a compelling case for time-restricted eating as a viable and potentially preferable alternative to traditional dieting. By removing the stress of constant calorie surveillance and allowing for a more socially convenient eating schedule, intermittent fasting may represent a breakthrough in public health nutrition — especially in combating obesity, insulin resistance, and related metabolic disorders.