Transitions From Overweight to Obesity and the Rising Severe Obesity Burden Among Children and Adolescents in China.

Abstract

The shift from overweight to obesity predominance and the parallel rise in severe obesity among youth remain insufficiently characterized. This study examines the timing and pattern of this "Obesity-Overweight Reversal" in China. We analyzed individual-level data from six cycles (1995-2019) of the Chinese National Survey on Students' Constitution and Health. Trends and projections to 2030 were estimated using multinomial logistic regression. Associations between severe obesity and Human Development Index (HDI) were assessed using generalized additive models. From 1995 to 2019, BMI z-score distributions shifted rightward and broadened across demographic groups. Obesity-Overweight Reversal first appeared among urban boys in Tianjin by 2010 and expanded to additional provinces, particularly among boys in the Northeast. Severe obesity rose sharply, reaching 7.66% in Shandong boys in 2019; among girls, severe obesity remained lower but was projected to surpass 5% in the Northeast in 2030. The HDI-severe obesity associations were nonlinear, with a plateau at very high HDI. China has entered a turning point in the pediatric obesity epidemic since 2010. Pronounced subnational and sex-residence disparities point to the need for context-specific interventions. Monitoring BMI distribution shifts, severe obesity trends, and socioeconomic correlates is essential to inform prevention strategies.