Poor diet and lack of exercise cost the NHS £7 billion a year and cause many to die early. We aim to build and test an intervention to help teenagers eat better and exercise more. Habits formed as teenagers tend to last, and physical and psychological changes during adolescence make it an important time to help them form healthier habits. Making small sustained changes, e.g. eating more fruit and vegetables and being more active, can reduce risks of heart disease or diabetes in later life. Existing interventions for helping teenagers eat better or exercise more, only work for those ready to change, or who see diet and exercise as important.
- school-based interventions may be effective;
- face-to-face support is helpful;
- the role of friends/family is important;
- websites and smartphones are widely used;
- teenagers spend time playing games on phones and computers.