Body Composition Remodelling During GLP-1-Based Therapy: A Systematic Review and Meta-Analysis Using a Hierarchical Physiological Framework.
Maria Luizza Lopes Menezes, Maria Eduarda Güntzel Chiappa, Rodrigo Fuentes Kloss et al.
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In 30 seconds
This systematic review and meta-analysis assessed longitudinal changes in body composition during GLP-1 receptor agonist or dual incretin therapy in adults. Nineteen studies were eligible, but the primary comparative analyses included only three studies for adiposity and two for muscle quantity. Comparative findings suggested a possible direction toward greater adiposity reduction, but the pooled estimate had substantial heterogeneity and a wide confidence interval crossing the null. Muscle quantity evidence was also highly heterogeneous and imprecise; muscle quality could not be quantitatively pooled. Overall, the evidence was low to very low certainty and hypothesis-generating.
Key findings
- Three comparative studies informed the adiposity meta-analysis; the pooled estimate was heterogeneous and its wide confidence interval crossed the null.
- Muscle quantity findings came from two comparative studies and were highly heterogeneous and imprecise.
- Muscle quality outcomes could not be pooled because of methodological heterogeneity and incomplete variance reporting.
- Exploratory single-arm analyses found reductions in adiposity and body weight, while muscle quantity changes varied across studies.
Why it matters
Body weight reduction does not establish whether treatment preferentially reduces fat or affects skeletal muscle health. The review highlights that current comparative evidence is too limited to resolve these questions, and that lean-mass reduction alone should not be equated with sarcopenia. Standardized assessment of muscle quantity, quality, strength, and physical performance is important for interpreting body-composition changes.
What to keep in mind
Comparative evidence was limited to three studies for adiposity and two for muscle quantity, with substantial heterogeneity, imprecise estimates, and low to very low certainty. Muscle quality could not be quantitatively synthesized.