Earlier this year, three girls and a boy, all severely overweight and aged between 13 and 15, became the first recorded cases of white children in Britain to be diagnosed with type-two diabetes, a condition usually only seen in adults over 40.

ECONOMIST: Well past pear-shaped

When Mary Ann Sheveland was diagnosed with Type 2 diabetes two years ago, she found solace and a will to fight it by making friends online.

FORBES: Help For Diabetics Beyond The Doctor's Office

Think about it: Heart disease and type 2 diabetes, two of the biggest killers in the United States, are completely preventable by making comprehensive lifestyle changes.

CNN: Change your lifestyle, reverse your diseases

Recent research on 34 obese type 2 diabetic patients showed that almost three-quarters of those who underwent gastric bypass surgery showed no clinical signs of type 2 diabetes after two years.

BBC: 'My type 2 diabetes was cured after gastric bypass op'

This is based on estimates of the impact on inactivity on coronary heart disease, Type 2 diabetes, and two specfic cancers - breast and bowel - where lack of exercise is a major risk factor.

BBC: Sedentary lifestyle can kill

Diabetes comes in two varieties, type 1 and type 2.

ECONOMIST: Diabetes

Earlier this year an American study found that more than two hours of TV viewing per day significantly increased the risk of type-2 diabetes and cardiovascular disease, and more than three hours of daily viewing increased the risk of premature death.

BBC: Can watching TV make you die younger?