Effects of different metabolic equivalent of task on glycaemic control in children and adolescents with type 1 diabetes mellitus: a systematic review and meta-analysis

Objective This systematic review and meta-analysis investigated the impact of different metabolic equivalent of task (MET) levels on glycaemic control in children and adolescents with type 1 diabetes mellitus (T1DM). Methods Following PRISMA 2020 guidelines, PubMed, Embase, Web of Science, SPORTDiscus, and the Cochrane Library were searched up to July 2025 for randomized controlled trials comparing exercise interventions with routine care in T1DM patients aged 5–18 years. The primary outcome was HbA1c; secondary outcomes included fasting blood glucose, daily insulin dose, and time in range. MET values were calculated as intensity (MET) × duration (minutes) × frequency (per week). Subgroup analyses examined low (<600), moderate (600–1,200), and high (>1,200 METs-min/week) MET levels. Effect sizes were pooled using random-effects models. Results Fourteen RCTs involving 543 participants were included. Exercise significantly reduced HbA1c (WMD = −0.83%, 95% CI: −1.34% to −0.33%, p < 0.001) and fasting blood glucose (WMD = −41.38 mg/dL, 95% CI: −61.23 to −21.53, p < 0.001). Subgroup analyses showed the largest numerical HbA1c reduction in the moderate MET group (WMD = −1.21%, 95% CI: −1.94 to −0.49, p < 0.05), followed by the low MET group (WMD = −0.50%, 95% CI: −1.35 to 0.34, p > 0.05) and the high MET group (WMD = −0.30%, 95% CI: −1.12 to 0.52, p > 0.05); however, the test for differences between subgroups was not statistically significant ( Q = 3.05 p = 0.22). Conclusion The moderate MET group showed the largest numerical HbA1c reduction, although between-subgroup differences were not statistically significant. These findings support evidence-based exercise prescription in this population, though further research is needed to clarify dose–response relationships and long-term outcomes. Systematic Review Registration Unique Identifier, CRD42024563752.