There is no evidence to suggest that a computerised individually-tailored intervention prevents weight gain in adolescents
- Correspondence to: Katrina Wyatt
Child Health, Peninsula College of Medicine and Dentistry, Veysey Building, Salmon Pool Lane, Exeter EX2 4SG, UK;
Implications for practice and research
Little is known about effective interventions to prevent weight gain in adolescents.
Eight 15-min sessions using a computer with individual feedback on behaviours was ineffective in affecting weight status.
Future research should focus on the development of interventions which engage young people sufficiently to affect weight status is needed.
This study sought to determine the effectiveness of a computerised-individually tailored intervention to prevent excessive weight gain in 12–13-year-olds. Data for the prevalence of obesity in the Netherlands from 2009 show that 12.8% of the Dutch boys and 14.8% of the Dutch girls aged 2–21 years were overweight and 1.8% of the boys and 2.2% of the girls were classified as obese.1 Although this is a marked increase compared to data from 1980 and 1999, these rates are substantially lower than Mediterranean countries in Europe and the UK.2 Paediatric weight status is associated with a range of adverse health outcomes3 and obese youth are at an elevated risk for obesity in adulthood.4
This study was a cluster-randomised controlled trial involving 20 schools and 883 12–13-year-olds. Dietary, physical activity and sedentary behaviours were assessed using validated questionnaires as well as pedometer counts, at baseline prior to randomisation and at 4 month and 2 year follow up. Height and weight were measured, body mass index (BMI) calculated, and waist circumference and proportion overweight and obese were assessed at baseline and 4 and 12 month follow up. Fitness was assessed by a physical activity teacher using a shuttle run test, and activity was measured using accelerometry at 12 months only.
The intervention affected obesity-related dietary behaviours such as drinking sugar sweetened drinks, reduction in snacks and higher vegetable consumption at 4 month follow up, although the step count was lower in the intervention group at 4 month as was sports participation. However, the intervention had no effect on BMI, waist circumference or proportions overweight or obese.
The study design is robust and had objective anthropometric and physical activity outcome measures, although only 59% of adolescents participated suggesting that the design or intervention might not have been attractive to everyone. The intervention was eight sessions of 15 min per session and was delivered in a classroom by a teacher according to a manual.
Although the intervention was developed with a theoretical framework and included personalised feedback there are two issues which might offer some explanation as to why the it did not affect weight status. Firstly, the intensity of the intervention might not have been sufficient, and, secondly, whilst schools are a natural place to locate an intervention, other research that has been conducted in developing an obesity prevention programme, points to the need for creative methods, for example, using personnel external to the school to deliver the intervention.5 Childhood and adolescent overweight and obesity are not, as yet, an issue for schools. The use of traditional (ie, classroom) approaches to deliver healthy lifestyle messages (albeit personalised and using a medium which is attractive to young people) is probably not sufficient to engage young people to adopt different lifestyle behaviours.
Obesity results from an interaction between the individual and their environment—evidence from systematic reviews has pointed to the need to involve families in preventing obesity in children. Increasingly obesity prevention programmes are focusing on a whole system or community approach where a supportive environment for healthy behaviours is created. It is important to report interventions which have not been found to be effective. However, an accompanying process evaluation would be beneficial to contribute to the understanding of why the intervention did not affect behaviours sufficiently to affect weight status.