Since calorific foods are known to impair our body’s response to insulin, we may be unwittingly poisoning our brains every time we chow down on burgers and fries. People with type 2 diabetes, who have already developed insulin resistance, may be particularly at risk. “The epidemic of type 2 diabetes, if it continues on its current trajectory, is likely to be followed by an epidemic of dementia,” says Ewan McNay of the University at Albany in New York. “That’s going to be a huge challenge to the medical and care systems.