Aims: To assess if obese adolescents have a realistic perception of current body size and a reasonable expectation of body size outcome when starting a paediatric weight watcher´s (WW) treatment programme.

Methods: The tool used was a 7-point scale with gender relevant figures, ranging from thin to fat in a fixed, sequentially ordered way and with height held constant (Collins, M. E. 1991). Before starting up a 16-week paediatric WW programme, 34 subjects (age 10-17, mean 13.6 years, 20girls) filled in their rated actual body size and their expected body size after treatment. Obesity was defined according to International Obesity Task Force measured with Body mass index standard deviation score(BMI SD).

Results: The Mean score for chosen current body size picture was 6.0,min.- max.values 5-7 and mean score 4.4, min-max.values 3-5 for the expected body size picture. Children’s choice of body figure correlated to their BMI SD as follows: Picture 5, BMI SD = 2.96 (n=4), Picture 6, BMISD = 3.07 (n=25), Picture 7, BMI SD 3.61 (n=5), R=0.40*. The mean picture difference was 1.65 min.-max value 1-3. The slimmest figures 1 and 2 were never chosen.

Conclusions: Obese adolescents appear to have a realistic perception of their current body size and reasonable expectations of body size outcome after treatment intervention. The risk of inducing anorectic behaviour when starting the treatment appears to be small in adolescents with obesity.