Weight perceptions in a population sample of English adolescents: cause for celebration or concern?

To examine the proportion of normal-weight adolescents who consider themselves to be too heavy (size overestimation), and the proportion of overweight or obese adolescents who consider themselves to be about the right weight or too light (size underestimation), in large population-based samples collected over 8 years in England.

Data were from the Health Survey for England between 2005 and 2012: an annual survey of households representative of the English population. We analysed data from 4979 adolescents (2668 boys, 2311 girls) aged 13 to 15 years old whose weight status was defined as normal weight or overweight/obese based on body mass index standard deviation scores (BMI-SDS) derived from objective measurements of height and weight and using International Obesity Task Force standards. Weight perception was based on the adolescent's choice from the following descriptors: 'about the right weight', 'too heavy' or 'too light'.

The majority of normal-weight adolescents (83% of boys, 84% of girls) correctly identified themselves as 'about the right weight'. Overestimation was uncommon, with only 7% of normal-weight teens (4% of boys, 11% of girls) identifying themselves as 'too heavy'. In contrast, only 60% of overweight/obese adolescents (53% of boys, 68% of girls) correctly identified themselves as 'too heavy', whereas 39% (47% of boys, 32% of girls) underestimated, identifying themselves as 'about the right weight' or 'too light'. There were no significant changes in BMI-SDS or body size estimation over time (2005-2012).

Overestimation of body weight among normal-weight adolescents is relatively uncommon; potentially a cause for celebration. However, almost half of boys and a third of girls with a BMI placing them in the overweight or obese BMI range perceived themselves to be about the right weight. Lack of awareness of excess weight among overweight and obese adolescents could be a cause for concern.