Middle age spread can cause dementia with lack of exercise leading to 'rapid mental decline' according to study

Resistance to the hormone insulin sees the body fails to burn sugar and instead store it as fat - which is linked to Type 2 diabetes and brain disease

"A study found patients with insulin resistance, caused partly by obesity and lack of exercise, had more rapid mental decline.

Resistance to the hormone is where the body fails to burn sugar and stores it as fat, and is linked to Type 2 diabetes.

The University of Tel Aviv in Israel tested insulin levels and cognitive function in 500 people.

Follow-up tests 15 and 20 years later showed those in the top 25% for insulin inefficiency were more likely to have accelerated cognitive decline."