Combined effects of time-restricted eating and exercise on short-term blood glucose management in individuals with Type 2 Diabetes Mellitus: The TREx study, a randomised controlled trial

Abstract

Aims: Time-restricted eating (TRE) is a chrono-nutrition strategy where the daily 'eating window' is reduced to 8-10 h. We investigated the acute (14-h) effects of TRE, with and without post-meal exercise, on blood glucose and insulin concentrations in people with type 2 diabetes mellitus.

Methods: Fourteen participants (5 F, 9 M; HbA1c: 7.6 ± 1.0%) completed four conditions in this randomised crossover study: CON (eating window, 0800-2000 h), CON with exercise (CON + Ex; 0800-2000 h + 15 min walking at 60% VO₂peak, 45 min post-meal), TRE (eating window 1000-1800 h), and TRE with exercise (TRE + Ex, 1000-1800 h + 15 min walking as per CON + Ex), with standardised meals. Venous blood samples were collected at 26-timepoints and analysed for glucose and insulin concentrations. Statistical analysis used linear mixed-effects models with P < 0.05.

Results: Reducing the eating window had little effect on plasma glucose 14-h area under the curve (AUC). Exercise reduced insulin 14-h AUC (P=0.01) with no additive effect of TRE.

Conclusion: Post-meal exercise lowered 14-h insulin AUC, neither 8-h TRE nor post-meal exercise altered 14-h blood glucose compared with 12-h eating window. Future work should focus on long-term effects of TRE combined with exercise for enhancing blood glucose in people with type 2 diabetes mellitus.

Keywords: Exercise timing; Glucose; Insulin; Meal timing; Time-restricted eating; Type 2 diabetes mellitus.