VETisnietVET / FATaintPHAT

Background: Computer-tailored health education may be especially suited to address complicated health-related behaviors such as diet and physical activity (PA). These behaviors are associated with the most prominent public health issues of today: overweight and obesity and thus with type 2 diabetes, cardio-vascular diseases, and certain cancers. Furthermore, web-based computer-tailored health education might best appeal to the -Internet generation-, i.e. younger people, including children and adolescents. Diet and physical activity patterns are established in childhood and adolescence and healthy habits should therefore be encouraged in young people. Although a number of computer-tailored PA and diet modules have been developed for young people in recent years, these have not been tested as such for this population. Objective: The present study proposes to test the effectiveness of a web-based computer-tailored weight maintenance intervention aimed at 12-14 year olds.
Methods: We will test this application in a real-life implementation environment in a randomized controlled trial with a follow-up of four months and two years. Primary outcome indicators will be BMI and waist circumference as measured by research staff. Secondary outcomes will be energy balance related behaviours (consumption of fruit, vegetables, fibre, snacks, and soft drink, physical activity, and sedentary behaviour), psychosocial determinants of these behaviours, and cognitions related to weight maintenance, measured with self-administered questionnaires.

1. The intervention group will have a lower BMI/waist circumference, compared to the control group at follow-up;
2. The intervention group will have more favourable outcomes on the targeted behaviours, compared to the control group at follow-up;
3. The intervention group will be more aware of their risk behaviours and have more positive attitudes, perceived behavioural control and intentions to change for their risk behaviours, compared to the control group at follow-up;
4. Availability and accessibility of foods and physical activity opportunities moderates the intervention effects.
In addition to testing these main hypotheses, secondary analysis will be performed to answer other relevant research questions.

Intervention group:
The pupils in the intervention schools will use a computer-tailored intervention on weight gain related behaviours (physical activity, sedentary behavior, snack, fruit and vegetable, fiber and soft-drink consumption) during their first year of secondary school. The intervention will be used during school hours as part of the education program. The intervention will be used for an average of 2 hours (preferably divided by 8 times 15 minutes) within 10 subsequent weeks.

Control group:
The control group will receive regular school lessons. After two years the intervention will be available for the control group as well.