After Dinner Rest a While, After Supper Walk a Mile? A Systematic Review with Meta-analysis on the Acute Postprandial Glycemic Response to Exercise Before and After Meal Ingestion in Healthy Subjects and Patients with Impaired Glucose Tolerance

Abstract

Background The most effective way to cope with high blood sugar spikes is to engage in physical activity in temporal proximity to food intake. However, so far, it is unclear as to whether there is an optimal time for physical activity around food intake. Objectives We aimed to identify the impact of pre- and post-meal exercise on postprandial glucose excursions in humans with and without type 2 diabetes mellitus. Methods We conducted a systematic review with meta-analysis, PROSPERO registration number: CRD42022324070. We screened MEDLINE/PubMed, Cochrane/CINAHL/EMBASE, and Web of Knowledge until 1 May, 2022. We used the risk of bias rating with the crossover extension of the Cochrane risk of bias assessment tool II. Standardized mean differences (SMDs, Hedges’ g) with 95% confidence intervals (CIs) were calculated as pooled effect estimates of a random-effects meta-analysis. Eligibility criteria included three-armed randomized controlled trials comparing the acute effects of pre- and post-meal exercise to a no-exercise control in humans. Results Eight randomized controlled trials (crossover trials, high risk of bias) with 30 interventions in 116 participants (47 diagnosed with type 2 diabetes, 69 without type 2 diabetes) were eligible. Exercise after meal ingestion (real food or meal replacement drinks) led to a reduction in postprandial glucose excursions compared with exercise before eating (15 effect sizes; SMD = 0.47 [95% CI 0.23, 0.70]) and an inactive control condition (15 effect sizes; SMD = 0.55 [95% CI 0.34, 0.75]. Pre-meal exercise did not lead to significantly lower postprandial glucose compared to an inactive control (15 effect sizes; SMD = − 0.13 [95% CI − 0.42, 0.17]). The time between meal and exercise (estimate = − 0.0151; standard error = 0.00473; Z = − 3.19; p = 0.001; 95% CI − 0.024, − 0.006) had a moderating influence on postprandial glucose excursions. Conclusions Exercise, i.e., walking, has a greater acute beneficial impact on postprandial hyperglycemia when undertaken as soon as possible after a meal rather than after a longer interval or before eating. Clinical Trial Registration The review was pre-registered in the PROSPERO database (CRD42022324070). The date of submission was 07.04.2022, with the registration on 08.05.2022.

Exercise Prescription for Postprandial Glycemic Management

“…The relationship between the timing of physical exercise and meals has garnered increasing attention for its potential to improve blood glucose levels after eating [ 10 , 12 , 13 , 14 , 21 ]. Given the crucial role of timing in exercise prescriptions, it has been suggested to introduce a third “T” into the FITT principles (frequency, intensity, time, and type) to emphasize this [ 22 ].…”

“…These conditions have been associated with an elevated susceptibility to developing cardiometabolic disorders and complications related to diabetes [ 1 , 3 , 6 , 7 , 8 , 9 ]. Nutrition and exercise are crucial as primary interventions to mitigate excessive glycemic responses in both healthy people and people with diabetes [ 10 , 11 , 12 , 13 , 14 ]. Nevertheless, despite the well documented benefits of exercise, sedentary behaviors are alarmingly on the rise across populations, contributing to an increased incidence of cardiometabolic disorders [ 15 , 16 , 17 , 18 , 19 ].…”

“…Numerous studies have previously highlighted the advantages of exercise in regulating post-prandial blood glucose levels [ 10 , 11 , 12 , 13 , 14 ]. The American College of Sports Medicine (ACSM) has recently reiterated the significance of postprandial exercise for individuals with type 2 diabetes (T2D), recommending at least 45 min of any exercise type, at any intensity, after meals to improve postprandial glucose response [ 20 ].…”

The growing use of continuous glucose monitors in people without diabetes: an evidence‐free zone

“…Similarly, advice to undertake short periods of physical activity after meals could also be beneficial. 52 The use of CGMs alongside structured advice could potentially leverage the benefits of short-term biofeedback, while avoiding the pitfalls of a solely glucocentric approach to eating (Table 1).…”

“…The short‐term biological feedback offered by a CGM may provide positive reinforcement. Similarly, advice to undertake short periods of physical activity after meals could also be beneficial 52 …”