A 3-year longitudinal study of effects of parental perception of children's ideal body image on child weight change: The Childhood Obesity Study in China mega-cities

This study examined prevalence of childhood overweight and obesity (ov/ob) and central obesity in five mega-cities across China (Beijing, Shanghai, Xi'an, Nanjing and Chengdu); described parental perceptions of children's ideal body image (IBI); and prospectively examined associations between parental perception of child IBI and child weight changes over 3 years. In this NIH-funded, open cohort study, data were collected from students and their parents in 2015, 2016 and 2017 (n = 3298, in 3 waves). Cross-sectional analysis included all 3298 children; longitudinal data analysis used mixed effects models and included 1691 children aged 6–17 years with ≥two body mass index (BMI) measurements during 2015–2017. Ov/ob prevalence based on Chinese age-sex-specific BMI cut-points was 30.0%. Based on waist-to-height ratio (WHtR), the abdominal obesity rate was 19.8%. Parents reported different preferred IBI for boys vs girls, being about 3 times more likely to select ov/ob as ideal for boys than for girls (4.5% vs 1.5%, respectively, P < .001). In longitudinal analysis, children whose parents selected ov/ob as ideal had higher BMI Z-scores and WHtR increase over time than those whose parents selected an average body image (β [SE] = 0.042 [0.011], and β [SE] = 0.010 [0.004], respectively, all P < .05). Ov/ob rates were high among children in major cities in China. Chinese parents preferred a heavier ideal body image for their boys. Health promotion programs should help empower parents and their children to develop appropriate body images and maintain healthy body weight.