To systematically synthesise the evidence of the MONW phenotype in children and adolescents aged 3–18 years, and to identify early-life determinants.
Approach:
Methodology: This systematic review followed PRISMA 2020 guidelines and searched multiple databases for observational studies of children and adolescents aged 3–18 years with normal BMI and at least one metabolic abnormality.
Key Findings:
The reported prevalence of MONW ranged from 10.6% to 56.2%, varying by diagnostic criteria and population.
Children with MONW consistently showed higher visceral adiposity, insulin resistance, dyslipidaemia, hypertension, impaired glucose metabolism, and elevated markers of low-grade inflammation despite having normal BMI.
Early-life determinants included extremes of birth weight, rapid infant weight gain, adverse maternal metabolic status, unhealthy dietary patterns, and sedentary behaviour.
Interpretation:
MONW is a clinically relevant but under-recognised phenotype in children, indicating that reliance on BMI alone may delay the identification of at-risk individuals.
Limitations:
Overall risk of bias across studies was low to moderate, with concerns about residual confounding and heterogeneous MONW definitions.
Conclusion:
Early risk stratification integrating metabolic proofing and central adiposity measures is necessary for timely prevention of long-term metabolic disease.
