A surprising study shows that being overweight in middle age may reduce the risk of developing dementia.
This is a contradiction to all previous research.
Scientists looked at two million people.
They found the underweight participants were far more likely to develop memory problems.
However, the very obese had a 29 percent lower risk.
The next step is to examine their diets, to see if they might be gaining dementia-fighting nutrients in the extra food they consume.