You could live longer if you eat less… according to Washington University nutrition expert Luigi Fontana.

He studied a group of men and women on healthful, low calorie diets and others of the same age and sex who ate more calories and higher amounts of fat over six years. "This is the first study to suggest, strongly suggest, that calorie restriction may delay primary aging."

Washington University nutrition expert Louigi Fontana

Fontana focused on the lower chambers of the heart, which he says, become less flexible with age. "It's the same as a young tree. The branch of a young tree is very flexible. As the tree gets older, the branch becomes stiffer. So that's the same in the ventricle."

Fontana says people on the low-calorie diet had hearts that looked 15 years younger compared with the control group that did not curb their appetites. But he says simply cutting calories isn't the formula for a healthier heart. It is paying attention to what you eat. "Calorie restriction does not mean eating half a hamburger, half a pack of French fries and half a glass of one of these sugary beverages."

Instead, Fontana suggests replacing that menu with healthier nutrient-dense foods like whole grains, beans and different types of fruits and vegetables. His work is reported in the Journal of the American College of Cardiology.