Time-restricted eating (TRE) has gained attention as a weight loss strategy, but is it the daily fasting periods that contribute to shedding pounds, or is it simply a reduction in total food intake? A new study suggests it’s the latter, indicating that the decrease in calories might be the key factor behind weight loss.
Researchers from Johns Hopkins University in the US conducted a study with 41 adult participants who had obesity and either prediabetes or diet-controlled diabetes. The volunteers were split into two groups: one followed a time-restricted eating pattern, and the other continued with a usual eating pattern. Both groups were provided with calorie-matched diets, allowing the researchers to isolate the impact of TRE.
The results showed significant weight loss in both groups, but the findings suggest that the reduced calorie intake, rather than the eating schedule, was the primary factor. Participants in the TRE group, who were allowed to eat only between 8 am and 6 pm, lost an average of 2.3 kilograms (5.1 pounds). Those in the usual eating pattern (UEP) group, with a 16-hour window for eating, lost an average of 2.6 kilograms (5.7 pounds).
“In the setting of isocaloric eating, TRE did not decrease weight or improve glucose homeostasis relative to a UEP, suggesting that any effects of TRE on weight in prior studies may be due to reductions in caloric intake,” the researchers noted in their published study.
In addition to weight loss, other health markers, such as glucose levels, waist circumference, blood pressure, and lipid levels, were similar between the two groups, reinforcing the idea that the calorie count is more critical than the timing of meals.
While the study’s sample size was relatively small, with participants monitored for only 12 weeks, the findings add to the growing body of evidence around effective weight loss strategies. The study suggests that time-restricted eating might be more about providing a simple way to manage calorie intake, rather than having a unique effect on metabolism or body composition.
In an editorial accompanying the study, Krista Varady and Vanessa Oddo, researchers not involved in the study, commented that the results indicate “TRE is effective for weight loss, simply because it helps people eat less.”
The researchers pointed out that while TRE might not be any more effective than other dietary approaches, it can offer a simpler method for those seeking to reduce obesity by eliminating the need for calorie counting. This could make it an attractive option for people looking for an easy-to-follow weight loss plan.
The study’s findings are detailed in the Annals of Internal Medicine.
