4. Discussion
obesity, disordered-eating behavior, overweight, adiposity, weight loss
OBESITY, CHILDHOOD OBESITY, DISORDERS, ADIPOSITY, COMPLICATIONS
After the 9-month intervention, the proportions of the children’s body size perceptions and body size expectations conducive to weight loss in the intervention group increased more than that in the control group. The multifaceted intervention could effectively improve the children’s body image. In the children whose baseline nutritional status was “normal weight with higher BMI” or “overweight/obese”, the changes in body image conducive to weight lose partly mediated the improvement by the intervention on the children’s adiposity indicators. That is, this multifaceted intervention for childhood obesity can partially decrease the level of children’s adiposity indicators through improving their recognition of and attitude towards their own body size.Current obesity studies have rarely found a positive effect of interventions on children’s body image [To our knowledge, this is the first study to identify the mediating role of body image in the effects of an intervention on childhood obesity. Possible explanations could be found from health behavior theories such as the Transtheoretical Model and Health Belief Model. According to the Transtheoretical Model [The study results revealed that an improvement in the children’s body image was associated with changes in adiposity indicators. Body image conducive to weight loss led to larger decreases in their BMIs, BMI Z scores, waist circumferences and body fat percentages. In addition to obesity, the association between body image indicators and mental health was also found in previous studies. Body dissatisfaction was associated with quality of life impairment and shown to impact emotional well-being [Given the increasingly high prevalence and adverse impact of mental health disorders among children with overweight and obesity, the overall goal of obesity treatment in this vulnerable population is to prevent negative lifelong health complications, both medical and psychological. This suggests that psychological health should be considered an important intervention outcome, equal to physiological health. Assessing emotional well-being is also warranted in obesity interventions to further confirm the benefits in multiple dimensions of children’s overall health brought by integrated interventions specifically targeting body image. Negative body image is thought to be a shared risk factor of obesity and disordered-eating behavior [Generally speaking, when children recognized that they were overweight or expected to be thinner, they would be more likely to exhibit weight control behaviors, such as a healthy diet and physical exercise [The main strength of this study included the study design being based on a cluster randomized controlled trial. The intervention longitudinal data not only allowed comparisons between baseline and the end of the trial, but also between the intervention group and the control group, which could provide more scientific and persuasive evidence on sequential associations. In addition, a generalized linear mixed model was used and the correlation due to the clustering of children within schools was considered in the model. Finally, our study conducted mediation analyses and explored the mediating role of body image between the intervention and the changes in adiposity indicators. For the first time, changes in body size perception and body size expectation were confirmed to be important factors associated with the beneficial effects of an intervention.This study had some limitations. Firstly, as the age range of the children was narrow (8~10 years old), the effects in children of other age groups needs to be further explored. Secondly, the intervention duration was relatively short (9 months), which limited the opportunity for analysis of the long-term impact of the intervention on the children’s body image, and to explore the association between the children’s body image and childhood obesity on a larger time scale. However, a nine-month intervention does not belong to the short-term intervention study category (less than three months). Thus, the findings from this study still have significance for future research. Additionally, disordered-eating behavior which was found to be closely associated with body image was not considered in this study. In addition to adiposity indicators, exploring the influence of body image on these psychosocial outcomes in the future is also needed to promote overall health of children.