A very low calorie diet can help the heart age more slowly, according to researchers who released what they call the first-ever human study on the subject. The findings confirmed earlier studies on mice and rats that demonstrate the cardiac benefits of a restricted calorie diet.

The study looked at the heart function of 25 members of the Caloric Restriction Society, ages 41 to 64, who consume 1,400 to 2,000 nutritionally balanced calories per day. They were compared to 25 people who eat a typical Western diet, consuming 2,000 to 3,000 daily calories on average.

The balanced way to go about it, the researchers suggest, is to adopt a heart-healthy Mediterranean dietary approach, for which cookbooks and diet plans abound. That approach centers on fruits and vegetables, beans, whole grains, fish and olive oil. Avoid refined foods, sodas, desserts, sugar and white bread and pasta, says Fontana.

Past research has shown that portion size can play a vital role in a person's calorie intake; if there's more food on the plate, more food goes into the stomach -- even if the diner could feel satisfied with less.