Effects Of Time Restricted Eating And Exercise On Glycaemia In Type 2 Diabetes: Trex Study

Time-restricted eating (TRE) is a chrono-nutrition strategy in which the daily ‘eating window’ (the time between the first and last energy intake) is typically reduced from >12 to 8-10 h. While there is growing evidence that TRE improves glycaemic management, there is a lack of knowledge of the acute effects of TRE within the context of other behaviours, such as exercise, in people with Type 2 Diabetes (T2D). PURPOSE: We investigated the acute (14-h) effects of reducing the eating window from 12-h (CON) to 8-h (TRE), with and without a post-meal 15 min bout of exercise (CON+Ex and TRE + Ex), on blood glucose and insulin concentrations in people with T2D. METHODS: Fifteen participants (5 F,10 M; HbA1c: 7.6 ± 1.0%) completed the 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% peak aerobic capacity, 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). Standardised meals were provided for each condition and the evening before each trial. Venous blood samples (6 mL) were collected at 26 time points (30 min-hourly, 0800-2200 h and the following morning at 0800 h) during each condition and analysed for plasma glucose and insulin concentrations, used to calculate the total area under the curve (AUC). Statistical analysis was conducted using linear mixed-effects models with significance set at P < 0.05. RESULTS: Modifying the eating window had no effect on plasma glucose AUC. Exercise reduced insulin AUC (-38 uIU/Lx14 h, 95%CI: -2 to -74 uIU/Lx14 h, P = 0.01) but no effect of TRE was shown. TRE lowered the 2-h post-lunch and post-dinner iAUC (-141 mmol/Lx2 h; 95%CI: -229 to -52 mmol/Lx2 h, P = 0.003; -203 mmol/Lx2 h; 95%CI: -288 to -119 mmol/Lx2 h, P < 0.001) and exercise lowered the 2-h post-dinner iAUC (-87 mmol/Lx2 h, 95%CI: 0 to -173 mmol/Lx2 h, P < 0.001). CONCLUSION: Post-meal exercise had a potent effect on 14-h insulin AUC, where neither 8-h TRE or exercise altered 14-h glycaemia, compared to a 12-h extended eating window. TRE had the greatest impact on lowering post-prandial glycaemia. Future work should focus on longer meal timing and exercise interventions for improving glycaemia in people with T2D. Supported by: This study was funded by an internal Exercise and Nutrition Research Program grant awarded to EBP.