UC Berkeley

Abstract Background Thin children are less muscular, weaker, less active, and have lower performance in measures of physical fitness than their normal weight peers. Thin children are also more frequently subjected to teasing and stigmatization. Little is known about thin children's weight perceptions, desired weight and attitudes and behaviours towards food and exercise. The study aimed to compare perceived weight status, desired weight, eating and exercise behaviours and advice received from parents among thin, overweight, obese or normal weight Australian children and adolescents. Methods The sample included 8550 school children aged 6 to 18 years selected from every state and territory of Australia. The children were weighed, measured and classified as thin, normal, overweight or obese using international standards. The main outcome measures were perceived and desired weight, weight related eating and exercising behaviours, and advice received from parents. Results The distribution of weight status was - thin 4.4%; normal weight 70.7%; overweight 18.3%; and obese 6.6%. Thin children were significantly shorter than normal weight, overweight or obese children and they were also more likely to report regularly consuming meals and snacks. 57.4% of thin children, 83.1% of normal weight children, 63.7% of overweight and 38.3% of obese children perceived their weight as "about right". Of the thin children, 53.9% wanted to be heavier, 36.2% wanted to stay the same weight, and 9.8% wanted to weigh less. Thin children were significantly less likely than obese children to respond positively to statements such as "I am trying to get fitter" or "I need to get more exercise." Parents were significantly less likely to recommend exercise for thin children compared with other weight groups. Conclusions Thin children, as well as those who are overweight or obese, are less likely than normal weight children to consider their weight "about right'. Thin children differ from children of other weights in that thin children are less likely to desire to get fitter or be encouraged to exercise. Both extremes of the spectrum of weight, from underweight to obese, may have serious health consequences for the individuals, as well as for public health policy. Health and wellness programs that promote positive social experiences and encourage exercise should include children of all sizes.