Expert Review
Conflicts of interest:
None
Take Home Message:
- Individuals living with obesity or who have type 2 diabetes may find it difficult to control their blood sugar levels after a meal.
- However, exercise after a meal can aid the uptake and use of sugar in the body.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
- Impaired glucose control after eating is associated with poor health outcomes and the development of type 2 diabetes mellitus (T2DM).
- Exercise has been shown to reduce blood glucose levels.
- As a result, it has been debated whether to recommend exercise after eating for people with T2DM.
- This aimed to determine the effect of postprandial exercise (PPE) on glucose control.
Methods
- This systematic review and meta-analysis of peer reviewed publications only included clinical studies in adults with overweight, obesity or T2DM, and studies in English.
- Children and pregnant women were excluded from the study.
Results
- 31/1290 studies were included in the final analysis.
- Postprandial exercise was shown to decrease 24 hour mean glucose concentrations compared to control (Hedge’s g = −0.328; SE = 0.062; 95% CI = −0.453, −0.203; p < 0.001), with a high level of consistency across studies (I2=0).
- There were no differences between whether subjects performed postprandial high intensity interval exercise (HIIE) or continuous moderate-intensity exercise (CMIE) (Hedge’s g = 0.152; SE = 0.104; 95% CI = −0.075, 0.397; p = 0.170).
- Postprandial exercise was shown to be more effective in controlling postprandial hyperglycaemia than exercising before a meal (Hedges’ g = −0.271; SE = 0.072; 95% CI = −0.357, −0.085; p < 0.05).
- Sub-analysis showed that exercise for less than 30 minutes duration had a reduced effect on postprandial glucose levels compared to exercise duration of more than 30 minutes (chi-square Q = 4.361, p < 0.05).
Conclusion
- Exercise following a meal is effective at controlling postprandial hyperglycaemia.
- HIIE and CMIE are equally effective at preventing postprandial hyperglycaemia if at least 30 minutes of exercise is performed.
- Exercise within 60 minutes of eating may be the most effective way to reduce postprandial glucose levels for individuals with T2DM.
Clinical practice applications:
- Individuals with type 2 diabetes or who are living with obesity may benefit from exercise following a meal to help control blood sugar levels.
- It doesn’t matter what form of exercise is performed just if it is at least of moderate intensity for 30 minutes.
- This exercise needs to be performed within an hour of eating.
- This may affect timing and amount of medication needed, which should be monitored.
Considerations for future research:
- Research on the effect of postprandial exercise on weight loss in individuals with type 2 diabetes or who are living with obesity would be of benefit.
- This would help to understand how exercise timing might also affect weight loss.
Abstract
Studies investigating the acute effect of postprandial exercise (PPE) on glucose responses exhibit significant heterogeneity in terms of participant demographic, exercise protocol, and exercise timing post-meal. As such, this study aimed to further analyze the existing literature on the impact of PPE on glycemic control in overweight individuals and individuals with obesity and type 2 diabetes (T2DM). A literature search was conducted through databases such as PubMed, CINAHL, and Google Scholar. Thirty-one original research studies that met the inclusion criteria were selected. A random-effect meta-analysis was performed to compare postprandial glucose area under the curve (AUC) and 24 h mean glucose levels between PPE and the time-matched no-exercise control (CON). Subgroup analyses were conducted to explore whether the glucose-lowering effect of PPE could be influenced by exercise duration, exercise timing post-meal, and the disease status of participants. This study revealed a significantly reduced glucose AUC (Hedges' g = -0.317; SE = 0.057; p < 0.05) and 24 h mean glucose levels (Hedges' g = -0.328; SE = 0.062; p < 0.05) following PPE compared to CON. The reduction in glucose AUC was greater (p < 0.05) following PPE lasting >30 min compared to ≤30 min. The reduction in 24 h mean glucose levels was also greater (p < 0.05) following PPE for ≥60 min compared to <60 min post-meal and in those with T2DM compared to those without T2DM. PPE offers a viable approach for glucose management and can be performed in various forms so long as exercise duration is sufficient. The glucose-lowering effect of PPE may be further enhanced by initiating it after the first hour post-meal. PPE is a promising strategy, particularly for patients with T2DM. This manuscript is registered with Research Registry (UIN: reviewregistry1693).
