In Obese Patients Without Diabetes, 12 Weeks of Time-Restricted Eating (TRE) Does Not Alter β-Cell Function: A Randomized Pilot Study

Abstract

Impairment of β-cell function is a precursor to impaired glucose tolerance, which is a pathophysiological basis for the development of Type 2 Diabetes Mellitus (T2DM). Previous literature has reported varying effects of TRE on metabolic measures in different populations, yet the effect of TRE on β-cell function has not been well-characterized. We hypothesized that in obese patients without diabetes, 12 weeks of TRE (8-hour eating window) would improve β-cell function relative to baseline and the unrestricted eating group (non-TRE). Participants (17 women and 3 men; (mean ± SD); 45.5±12.1 years; BMI 34.1±7.5 kg/m2) with a prolonged eating window (15.4±0.9 hours) were randomized to either TRE (n=11) or non-TRE (n=9) for 12 weeks. Weight and 2-hour oral glucose tolerance (OGTT) were measured during at baseline and end-intervention. Β-cell function was assessed by multiple OGTT-based measures, including Glucose AUC, Insulin AUC, insulinogenic index, disposition index, QUICKI index, Matsuda index, Stumvoll index, and Avignon index. At baseline, these measures are within normal range across both groups. We found that TRE did not significantly alter these measures relative to baseline or the non-TRE group. In addition, the degree of eating window restriction did not correlate with any observed changes in β-cell function. We concluded that in obese patients without diabetes, TRE did not significantly alter β cell function; whether TRE may be beneficial in patients with dysglycemia warrants further investigation.