Acute effects of interrupting prolonged sitting with short bouts of physical activity on postprandial metabolism in sedentary adults: A multi-level meta-analysis.

OBJECTIVES: To evaluate the acute effects of short activity breaks interrupting prolonged sitting on postprandial glucose, triglycerides and insulin in sedentary adults, and to explore dose-response relationships and meal-type differences. STUDY DESIGN: Systematic review and meta-analysis of randomised cross-over trials. METHODS: We searched PubMed, Web of Science, Cochrane Library, ProQuest, EBSCO and CNKI up to 9 May 2026. Fifteen studies were included. Postprandial glucose was analysed using a three-level model, insulin with a two-level model, and triglycerides with a conventional random-effects model. Dose-response relationships were examined using three-level meta-regression (MET-min/day). Heterogeneity was partitioned, and sensitivity analyses, publication bias tests and GRADE assessment were performed. RESULTS: Short activity breaks significantly reduced postprandial glucose (Hedge's g = -0.726, 95% CI -1.167 to -0.285), triglycerides (g = -0.48, 95% CI -0.74 to -0.22) and insulin (g = -0.784, 95% CI -1.144 to -0.425). A linear dose-response relationship was observed for glucose: each 10 MET-min/day increment reduced g by 0.08 (95% CI -0.108 to -0.051). For insulin, no dose-response relationship was found (p = 0.409). No significant meal-type differences were detected (p = 0.317). CONCLUSIONS: Interrupting prolonged sitting with short activity breaks improves postprandial glucose and insulin in sedentary adults, and reduces triglycerides, albeit with a prediction interval that included zero. The glucose benefit follows a linear dose-response pattern and is similar across breakfast, lunch and dinner. No such dose-response relationship was observed for insulin.