Childhood overweight is a worldwide public health problem and identifying effective strategies for the prevention of childhood overweight remains a priority. Parents play an important role in the development of their child's health related behaviours⁽ Reference Rhee, De Lago and Arscott-Mills ^{1 )} and are relied upon to recognise unhealthy weight gain and take the appropriate action⁽ Reference Parry, Netuveli and Parry ^{2 )}. Evidence indicates, however, that parents tend not to recognise when their child is overweight; they make visual comparisons within peer groups, tend to rely on extreme cases as a reference point⁽ Reference Jones, Parkinson and Drewett ^{3 )} and are more sensitive to visual cues such as skinfolds than body mass index (BMI)⁽ Reference Parkinson, Drewett and Jones ^{4 )}. The aim of the present study was to develop a visual method to improve parents' ability to correctly assess their child's weight status.

3D body scans of children aged 4–5 years and 10–11years were obtained using 3D surface body scanning technology. Height and weight measurements were also taken and weight status determined using UK90 criteria⁽ Reference Cole, Freeman and Preece ^{5 )}. New age- and gender-specific body image scales (BIS) of known BMI based on UK90 criteria were developed using the body scan data, associated BMI information and qualitative work with a parent panel and professional group.

3D body scans and body composition data were obtained from 543 children (350 4–5 years, 193 10–11 years). Eighteen focus groups/interviews were completed with 39 parents and 5 health professionals. An example BIS of known BMI is shown in Fig. 1.

Fig. 1. Body image scale of known BMI for boys aged 4–5 years.

The present study developed BIS of known BMI for children aged 4–5 and 10–11 years. The effectiveness of the scales in improving parental recognition of childhood overweight is being tested in a large cluster randomised trial at 1 and 12 months follow-up.