Researchers in Aberdeen are beginning a £500,000 three-year study to find out what lifestyle changes work best to stop people from becoming obese.
About 24 million people in the UK are overweight or obese
It is estimated that almost half the UK population is overweight or obese.
This puts huge strain on the NHS, with increased risk of diabetes, cancer and heart disease.
Aberdeen University hopes the study, funded by the National Preventative Research Initiative, will provide advice for policymakers and the public.