Developmental Modularity and Evolutionary Integration: A Morphometrics Study of the Hand Among Indian Populations.

INTRODUCTION

Adolescent overweight and obesity are increasing across South Asia, contributing to diabetes and other noncommunicable diseases. Previous reviews have examined prevalence and selected associated factors, but evidence remains heterogeneous across countries, populations and adiposity definitions. This narrative review synthesised recent evidence on prevalence and factors associated with overweight and obesity among South Asian adolescents.

METHODS

We conducted a structured narrative review reported in accordance with the Scale for the Assessment of Narrative Review Articles. PubMed, Scopus and Google Scholar were searched for peer-reviewed studies published from January 2015 to March 2025, supplemented by targeted searches through August 2026. Studies of adolescents aged 10-19 years and predominantly adolescent populations with overlapping age ranges were considered. Primary studies and evidence syntheses were analysed separately. Methodological quality was evaluated using design-appropriate Joanna Briggs Institute critical appraisal checklists, and findings were synthesised narratively.

RESULTS

Thirteen publications were included: eight primary studies and five systematic reviews or meta-analyses. Prevalence varied by population, setting, adiposity measure and classification system. Regional meta-analytic estimates were 12.4% for overweight, 6.6% for obesity and 19.3% for combined overweight/obesity, although these were not directly comparable with adolescent-specific primary studies. More consistent evidence concerned physical inactivity, sedentary behaviour and unhealthy dietary practices. Associations with socioeconomic position, urban residence, sex and gender, familial factors and media exposure were more limited and context dependent. Sleep, mental health, food insecurity and neighbourhood environments were insufficiently examined. Most primary evidence was cross-sectional and school based.

CONCLUSIONS

Adolescent overweight and obesity in South Asia are associated with behavioural, dietary and socio-environmental factors within changing food and urban environments. Interpretation is limited by heterogeneous definitions, uneven country coverage and predominantly cross-sectional designs. Standardised population-based and longitudinal studies, including out-of-school adolescents, are needed to guide context-specific prevention.