Efficacy and Safety of Time-Restricted Eating in Adults With Type 1 Diabetes: A Randomized Controlled Trial.

OBJECTIVE: Many adults with type 1 diabetes (T1D) have overweight or obesity, underscoring the need for effective dietary weight loss strategies in this population. Time-restricted eating (TRE) has emerged as a popular approach for weight loss; however, its efficacy and safety in T1D have not been evaluated. We examined whether TRE is more effective for reducing body weight than standard care (daily calorie restriction [CR]), or compared with a control group, in adults with T1D and overweight or obesity. RESEARCH DESIGN AND METHODS: Participants were randomized to one of three groups for 6 months: 8-h TRE (eating only between 12:00 p.m. and 8:00 p.m., without calorie counting) versus CR (25% energy restriction daily), and compared with a no-intervention control group. The primary outcome was percent change in body weight by month 6. RESULTS: Thirty-two participants were randomized. By month 6, body weight did not change significantly in the TRE group (-2.19% [95% CI -5.70, -1.31]) or CR group (-0.47% [95% CI -4.72, 3.78]) relative to a control group, or between TRE and CR groups (-1.73% [95% CI -5.37, 1.92]). HbA1c levels were significantly reduced by the TRE group when compared with the CR group (-0.46% [95% CI -0.80, -0.12]). There were no significant differences in total insulin dose or mean glucose levels across groups. TRE did not increase the risk for diabetic ketoacidosis, severe hypoglycemia, or severe hyperglycemia. CONCLUSIONS: These findings suggest that TRE may be a safe approach for reducing HbA1c levels in T1D, although not more effective for weight loss compared with CR or a control group.