Spatiotemporal variations in body mass index among Han adolescents aged 18 years across 27 provinces of China, 1985–2019: Results from eight successive national cross-sectional surveys

Abstract

Objectives

To investigate the spatiotemporal variations in body mass index among Han adolescents aged 18 years across 27 provinces of China from 1985 to 2019.

Study design

Cross-sectional epidemiological study.

Methods

A total of 141,406 adolescents aged 18 years were included from eight Chinese National Surveillance on Students’ Constitution and Health from 1985 to 2019. Body mass index data were extracted from 27 provinces in each CNSSCH. All provinces were categorized into seven regions. Linear regression was used to assess the trends.

Results

The population-based national body mass index of boys and girls aged 18 years from 27 provinces increased by 2.35 kg/m² and 1.40 kg/m², respectively (all p < 0.001). Body mass index has been greater and the increase was larger in North China and East China during the 34-year period. Body mass index has been smaller and the increase was smaller in South China and Southwest China. The Northeast China had the largest increase in body mass index, becoming the region with the largest body mass index through 2019.

Conclusion

The body mass index among Chinese adolescents aged 18 years across provinces increased from 1985 to 2019. Further national and local efforts are needed to address spatiotemporal variations in body mass index.