Abstract
Childhood obesity can affect both physical and mental health. Body-size misperception may lead to a lack of motivation to make healthy changes or to engage in unhealthy weight loss behaviors, increasing the possibility for obese children to become obese adults. To estimate the frequency of body-size misperception among children and adolescents, we conducted a cross-sectional study within another study on eating disorders in youth in Greece (National Institute of Educational Policy, act no. 04/2018). Between January and December 2019, two trained assistants visited 83 primary and secondary schools of the Region of Western Greece and interviewed 3504 children aged 10-16 years (CL 99%) and performed anthropometric measurements. Among the 3504 surveyed children, 1097 were overweight, including 424 obese, and 51 were underweight. The "perceived" BMI was not computed in 875 children (25%), who did not state their weight or height and were classified as non-responders. Weight bias was inversely related to BMI, the obese and overweight non-obese children underestimated their weight, while the underweight children overestimated it. Conversely, height bias was positively related to BMI bias. BMI bias was not related to sex, age, parental education, or place of residence. In conclusion, our study lends robust support to the existing evidence on unrealistic body images among overweight children and adolescents. Prompt recognition of such misperceptions may help in increasing motivation towards healthier eating habits, systematic physical activity, and weight-control interventions.