We've all been made aware of the risks tht obesity can have on our hearts, but new research indicates that it also puts you at risk of brain decline later in life.
A study of 250 people aged between 60 and 70 found those with a high body mass index (BMI) and big waists scored more poorly in cognitive tests.
A spokesperson from the UK Alzheimer's Society said: "We have all hear how a high BMI is bad for our heart but this research suggests it could also be bad for the head."
The study looked at the relationship between fat levels and cognitive performance in adults aged 60 or over.
The lead authour of the study, Dae Hyun Yoon, said: "Our findings have important public health implications. The prevention of obesity, particularly central obesity, might be important for the prevention of cognitive decline or dementia."
The spokesperson from the UK Alzheimer's Society, continued: "One in three people over 65 will die with dementia but there are things people can do to reduce their risk.
"Eating a balances diet, manintaing a healthy weight, exercising regularly and getting your blood pressure and cholesterol checked can all make a difference."
The study was published in the journal Age and Ageing.