Anthropometric characteristics of primary school-age children: accuracy of perception and differences by gender, age and BMI.

Background: Body perception has been mainly studied in adolescents and adults in relation to eating disorders and obesity, since such diseases are usually associated with a distortion in the perception of body size. The development of body perception in children was rather neglected despite the relevance of this issue in understanding the aetiology of health eating problems. The main aim of this study was to investigate body weight and body height perception in children, by gender, age and Body Mass Index (BMI), taking into account differences among underweight, healthy weight, overweight and obese children. Method: A school-based sample of 572 Italian children (49% boys) aged 6–10 were involved in a cross-sectional survey. Current weight and height were measured by standard protocols and BMI was calculated and converted in centile categories using the Italian growth curves for children. Perceived weight and height were assessed using visual methods (figures representing children of different weight and height). Results: About a third of the children do not show to have an accurate perception of their weight and height (weight: 36%; height: 32%): as for weight, an error of underestimation prevails and as for height, an error of overestimation prevails. In general, children who have different weight and height from the average tend to perceive their physical characteristics closer to average. However, overweight children underestimate their weight much more than obese children. Conclusions: Distortions in the perception of their physical features, weight and height, appear to be related to the aesthetic models of Western culture. The tendency to underestimate weight, particularly in overweight children, has implications in interventions for health promotion and healthy lifestyle in school aged children.