The Acute Effects of Interrupting Prolonged Sitting With Regular Activity Breaks on Postprandial Glucose and Insulin in Adults: A Systematic Review and Meta‐Analysis

BACKGROUND: Regular activity breaks improve postprandial glycemia, but the effects across different population groups and modes of breaks remain unclear. This systematic review and meta-analysis examined the impact of activity breaks on postprandial glucose and insulin response in adult populations. METHODS: Studies were identified from five databases until October 9, 2024. Eligible studies were acute (< 24-h duration) laboratory-based randomized crossover trials comparing postprandial glucose and/or insulin response between prolonged sitting and activity breaks (< 10 min, ≥ 3 breaks over 3 h). Risk of bias was assessed using the Downs and Black quality assessment tool. Random-effects meta-analysis was conducted including subgroup analyses by activity mode, frequency, and participant health/weight status. RESULTS: Overall 53 studies met the eligibility criteria; 39 were included in the meta-analysis. Compared with prolonged sitting, activity breaks lowered postprandial glucose incremental area under the curve (iAUC) (SMD -0.30, 95% CI -0.43 to -0.13) and insulin iAUC (SMD -0.30, 95% CI -0.46 to -0.14). Walking breaks had the greatest effect on glucose iAUC (SMD -0.33, 95% CI -0.48 to -0.17) and insulin iAUC (SMD -0.44, 95% CI -0.62 to -0.27), compared with other modes. Interrupting sitting every 15-20 min produced the largest reductions in glucose (SMD -0.51, 95% CI -0.83 to -0.19) and insulin iAUC (SMD -0.41, 95% CI -0.77 to -0.06). The largest reduction in glucose iAUC was observed in those living with obesity (SMD -0.52, 95% CI -1.07 to 0.03). CONCLUSION: Frequent short walking breaks, performed every 20 min, provide the most improvement in postprandial glucose and insulin response in adults.