Supermarkets sell fruit and vegetables in lunch box-sized portions these days, which is a great idea. And exercise is very important. When I was at school we had PE every day, but now it's less frequent. Walking to school and providing safe cycle routes can help. The statistics in our research indicate that we will have far higher numbers of obese adults in the near future, but the response should not be to put overweight children on diets and to force them to exercise, but for parents to ensure that their children have a healthy diet and to encourage them to be active in everyday activities such as walking to school.
Schools can act, too, by encouraging balanced meal choices and playground activities.
The selling-off of school grounds must be reversed and advertising of junk foods banned at children's viewing times. I don't think we should put children on diets. They are not active enough and don't get enough opportunities for physical activity. Forcibly restricting their food will discourage them from eating healthily. We need to encourage children and give them a positive experience of eating and exercise.