Obesity, body image, and its impact on children's eating and exercise behaviors in China: A nationwide longitudinal study.

Body image seems to mediate the association between obesity and health behaviors as well as weight control attempts. We examined the distribution of children's body image by demographic characteristics and their subsequent associations with eating, exercise, and weight change. Child body image and health behaviors from the China Health National Survey 2000-2011 were assessed at baseline and in follow-up for 6- to 17-year-old children during 2000-2011 using mixed models. There was a large discrepancy between children's actual weight status (overweight: 16.9%) vs. self-rated body image (fat: 2.4% in 2011). Less than 1% of children desired a fat body; girls were more likely to want to be thin (52.5% vs. 40.9%) than boys. About 11% of children needed to lose weight in order to be at their desired baseline. During follow-up, those needing weight loss to be as desired were more likely to attempt dieting to change their weight (OR, 95% CI=1.9, 1.1-3.5 in boys; 1.7, 1.1-2.5 in girls) and less likely to feel they had enough physical activity (OR, 95% CI=0.5, 0.4-0.7 in boys; 0.6, 0.5-0.9 in girls), although their weight gain had been significantly higher than those having consistent self and desired body images (β [SE]=0.4 [0.1] in boys; 0.2 [0.1] in girls, all p<0.05). However, no significant difference was shown in subsequent health behaviors among overweight children by body image discrepancy. The discrepancy in self vs. desired body image motivated children to change their obesity-related health behaviors among non-overweight children in China.