Study: Big belly bad for your heart even if not obese

"Exercise more, decrease sedentary time by taking the stairs or getting off the train one stop early and walking, increase your muscle mass with strength and resistance training, and cut out refined carbohydrates," he advised.

He added that doctors shouldn't assume that people with a normal BMI are not at risk of heart problems.

"Our study provides evidence that doctors should also measure central obesity [belly fat] to get a better picture of whether a patient is at risk," Medina-Inojosa said.