Weight, body mass index and behaviour change in a commercially run lifestyle programme for young people.

Background:   There are few practical, scalable, community-based solutions that provide ongoing support to combat the recent rapid rise in obesity in young people. A commercial weight management organisation (CWMO) has developed a tailored version of its programme for young people. The present study assessed the programme's impact on self-reported body weight, body mass index (BMI; kg m(-2) ) and health-related behaviour changes in participating young people.

Methods:   Seventy-nine current young members completed a web-based questionnaire on age, height, weight and self-reported eating and activity behaviours for when they joined the programme and at the time of survey. Inclusion criteria were age 11-15 years old and membership for at least 1 month. Subjects completed the questionnaire online via the CWMO website. This was a retrospective observational study without a control group. All data were self-reported.

Results:   Mean (SD) age was 13.4 (1.4) years and start weight was 78.5 (16.7) kg; 67% were >99th centile for BMI. Mean (SD) attendance was 23 (19) weeks; weight change was -5.0 (4.5) kg; BMI change was -2.5 (2.0) kg m(-2) ; and BMI Z-score change was -0.5 (0.4) (all P < 0.001). Height increased by 0.01 (0.03) m (P < 0.01); however, height Z-score remained unchanged. Regression analysis showed that BMI Z-score change was related to increased fruit and vegetable intake (P = 0.012), as well as a decrease in avoidance of moderate and intense activity (both P < 0.003).

Conclusions:   This programme for overweight and obese young people helped implement behaviour and lifestyle changes that were associated with significant reductions in self-reported weight and BMI Z-score, without compromising growth in height.