Middle age weight link to dementia risk
3 May 2011 Last updated at 12:27 BST
Middle aged people who are overweight but not obese are 71% more likely to develop dementia than those with a normal weight, according to research.
A link between obesity and dementia has long been suspected, but according to researchers in Sweden, carrying just a few extra pounds can also have an effect on your brain as you grow older.
Adam Brimelow reports.