Mismatch in children’s weight assessment, ideal body image and rapidly increased obesity prevalence in China: A 10-year nationwide longitudinal study

OBJECTIVES: This study examined secular trends in children’s weight status assessment, measured weight status and ideal body image, and their associations with subsequent changes in BMI, and it explored the differences between sociodemographic groups in China. METHODS: Longitudinal data from the China Health and National Survey of 4,605 children aged 6-17 collected during 2000-2011 were used and fitted to mixed models. RESULTS: Overweight/obesity prevalence increased from 6.5% to 16.8%, but children’s fat body perception remained around 2.0% between the years 2000 and 2011; 49.0% of children underestimated their weight status at baseline. Self-body image of most participants was tracked during follow-up. Children who perceived themselves as being fat at baseline had a higher BMI increase over time during follow-ups than those with an average body image (β[SE] =0.99[0.14]kg/m(2)/year, p <0.001). Boys, young, recent cohort, and rural children had higher BMI increases than their counterparts. Over time, thin body silhouette became more desirable (8.4% p higher, p<0.001). CONCLUSIONS: Chinese children experience a large incongruence between their weight status assessment, ideal body image, and actual weight status. Health promotion programs should examine their role in assisting children in developing healthy body images and gaining greater self-motivation towards promoting a healthy lifestyle.