The impact of time-restricted eating on beta-cell function in adults with type 2 diabetes: a randomized cross-over trial.

Abstract

Time-restricted eating (TRE) which consists of restricting the eating window to typically 4-8h (while fasting for the remaining hours of the day) has been proposed as a non-pharmacological strategy with cardio-metabolic benefits but little is known about its metabolic impact in type 2 diabetes (T2DM). We evaluated whether TRE can improve pancreatic beta-cell function and metabolic status in overweight individuals with early T2DM. In a randomized cross-over trial, 39 participants [mean 2.9 years of diabetes duration, baseline glycated hemoglobin (HbA1c) 6.6% ± 0.7% and body mass index (BMI) 32.4 ± 5.7 kg/m2] were randomized to either an initial intervention consisting of 6-weeks of TRE (20h-fasting/4h-eating) or standard lifestyle. The primary outcome of beta-cell function was assessed by Insulin Secretion-Sensitivity Index-2 (ISSI-2) derived from an oral glucose tolerance test. Trial registration: clinicaltrials.gov NCT05717127. As compared to standard lifestyle, TRE induced a 14% increase in ISSI-2 (+14.0 ± 39.2%, p = 0.03) accompanied by 14% reduction of hepatic insulin resistance as evaluated by HOMA-IR [-11.6% (-49.3-21.9), p = 0.03]. Fasting glucose did not differ between interventions, but TRE yielded a significant reduction in HbA1c (-0.32 ± 0.48%, p <0.001). These metabolic improvements were coupled by a reduction of body weight of 3.86% (-3.86 ± 3.1%, p <0.001) and waist circumference of 3.8 cm (-3.8 ± 7.5 cm, p = 0.003). TRE improved beta-cell function and insulin resistance in overweight patients with early diabetes, accompanied by beneficial effects on adiposity.