Systematic review and meta-analysis of metformin for pediatric overweight and obesity shows modest BMI reduction

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Archives of disease in childhood. Fetal and neonatal edition Published May 19, 2026 Medically reviewed May 19, 2026 Study authors: Theodoridis Xenophon, Papaemmanouil Androniki, Papageorgiou Niki, Chrysoula Lydia, Stabouli Stella, … PubMed ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider metformin as adjuvant therapy for pediatric overweight or obesity based on modest BMI and weight reduction.

This systematic review and meta-analysis examined the efficacy of metformin compared with placebo in children with overweight or obesity. Data were pooled from 19 original studies to assess changes in Body Mass Index (BMI), BMI-Z score, body weight, fasting insulin, and leptin concentrations. Secondary outcomes included adiponectin concentrations, resistin concentrations, and the adiponectin to leptin ratio.

Metformin demonstrated superiority over placebo for several primary outcomes. The mean difference (MD) for BMI was -1.07 kg/m with a 95% CI of -1.62 to -0.52. The MD for BMI-Z score was -0.09 with a 95% CI of -0.13 to -0.05. Body weight reduction showed an MD of -3.20 kg with a 95% CI of -4.21 to -2.19. Fasting insulin levels decreased by an MD of -3.38 µU/mL (95% CI -6.00 to -0.75), and leptin concentrations decreased by an MD of -3.73 ng/mL (95% CI -6.28 to -1.18).

No significant differences were observed between metformin and placebo for adiponectin concentrations, resistin concentrations, or the adiponectin to leptin ratio. Safety data, including adverse events and discontinuations, were not reported. The authors note that results regarding concentrations of adipokines and hormones are inconclusive. They emphasize the need for more randomized controlled trials with rigorous methodology and homogeneity in population and intervention characteristics. Metformin may have a role as an adjuvant therapy in managing overweight and obesity among the paediatric population.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedMay 2026

PMID41285564

View Original Abstract ↓

OBJECTIVE: The aim of this systematic review was to assess the effect of metformin on anthropometric indices, hormones and adipocytokine concentrations in children with overweight or obesity. METHODS: Eligible studies were searched via PubMed, Scopus, Cochrane Central Register of Controlled Trials, alongside clinical trial registries and the reference lists of included studies, from inception to October 2024. Screening was carried out independently by two reviewers, involving title-abstract screening for relevance, followed by full-text review for eligibility confirmation. Data extraction was performed by two independent investigators using an identical Excel spreadsheet. A meta-analysis was conducted using the random-effects model. RESULTS: A total of 19 original studies were deemed eligible for this systematic review. Metformin was more effective than placebo in improving Body Mass Index (BMI), BMI-Z score, body weight, fasting insulin and leptin concentrations (mean difference (MD) -1.07 kg/m, 95% CI -1.62 to -0.52; MD -0.09, 95% CI -0.13 to -0.05; MD -3.20 kg, 95% CI -4.21 to -2.19; MD -3.38 μU/mL, 95% CI -6.00 to -0.75; MD -3.73 ng/mL, 95% CI -6.28 to -1.18, respectively). There was no difference between metformin and placebo on adiponectin and resistin concentrations, as well as adiponectin to leptin ratio. CONCLUSION: Metformin may have a role as an adjuvant therapy in managing overweight and obesity among the paediatric population. Regarding the concentrations of adipokines and hormones, the results are inconclusive. More randomised controlled trials with rigorous methodology and homogeneity in population and intervention characteristics are needed to shed light on this topic. TRIAL REGISTRATION NUMBER: PROSPERO CRD42023401732.