Time-Restricted Eating Shows Promise in Managing Type 2 Diabetes

A randomized, clinical trial published in JAMA Network Open compared the effects of time-restricted eating (TRE) without calorie counting versus daily calorie restriction (CR) on weight loss and the lowering of hemoglobin A_1c (HbA_1c) levels in adults with type 2 diabetes (T2D).

The study, which took place from January 2022 to April 2023, included 75 participants between the ages of 18 and 80, all of whom had obesity and T2D. Participants were randomly assigned to 1 of 3 groups: the TRE group, in which individuals limited their eating to an 8-hour window from 12 p.m. to 8 p.m. without calorie counting; the CR group, in which individuals restricted their daily calorie intake by 25%; and a control group.

After 6 months, participants in the TRE group experienced a significant reduction in body weight by approximately 3.56%. In contrast, participants in the CR group saw a more modest reduction of 1.78%, and those in the control group had minimal changes.

Individuals in the TRE and CR groups demonstrated similar improvements in HbA_1c levels. Compared with the control group, patients in the TRE group saw a reduction of 0.91%, and those in the CR group saw a reduction of 0.94%.

Participants in the TRE group adhered to their eating window for a substantial portion of the week (an average of 6.1 out of 7.0 days). In contrast, 68% of participants in the CR group adhered to their prescribed calorie goals. The reduction in energy intake was greater for patients in the TRE group (−313 kcal/day) compared with the CR group (−197 kcal/day).

Investigators found that time in the euglycemic range, medication effect score, blood pressure, and plasma lipid levels did not differ significantly among the 3 groups. Furthermore, there were no reports of serious adverse events related to the dietary interventions.

“This randomized, clinical trial found that a TRE diet strategy without calorie counting was effective for weight loss and lowering of HbA_1c levels compared with daily calorie counting in a sample of adults with T2D,” the researchers wrote. They called for larger randomized, controlled trials with longer follow-up times to confirm their study’s findings.