2.3. Measurements
weight loss, weight-control behaviors
Two indicators (body size perception and body size expectation) were used to characterize two important dimensions of children’s body image: self-perceived weight status and body image dissatisfaction.Body size perception was measured using Ma figural stimuli, which were developed based on Collins figural stimuli [According to its association with weight-control behaviors, these two body image indicators were coded as binary variables (conducive to weight loss or not). The underestimation of body size was coded as 0 (not conducive to weight loss). The overestimation and correct estimation of body size were coded as 1 (conducive to weight loss). Moderate dissatisfaction and expectation to be thinner was coded as 1 (conducive to weight loss). Changes in these two indicators were also coded as binary variables. The changes conducive to weight loss were coded as 1 (including two cases: (1) the body image indicator was conducive to weight loss at both baseline and the final survey; (2) the body image indicator was not conducive to weight loss at baseline, but conducive to weight loss at the end of the trial). The remaining conditions were considered as changes that were not conducive to weight loss and coded as 0.The children’s weights and heights were measured to the nearest 0.1 kg and nearest 0.1 cm. Their waist circumferences were measured to the nearest 0.1 cm with Myotape body measure tape. Their body fat percentages were measured to the nearest 0.1% with a body component instrument (Tanita MC-780 MA).Body mass index (BMI) was calculated by dividing the weight (kg) by the square of the height (m