HEALTHY people who exercise and also eat chocolate regularly tend to have a lower body mass index than those who eat chocolate less often.

A US survey of more than 1000 adults, published as a research letter in the Archives on Internal Medicine, reinforces the notion that chocolate packs heart-healthy benefits, despite high calorie and sugar content.

People in the study reported eating chocolate an average of twice a week and exercising an average of 3.6 times a week. Their average age was 57.

Those who said they ate chocolate more often than the norm tended to have a lower ratio of weight over height, a calculation made by taking a person's weight and dividing it by their height times two.

''Adults who consumed chocolate more frequently had a lower BMI [body mass index] than those who consumed chocolate less often,'' said the study led by Beatrice Golomb at the University of California, San Diego. ''Our findings - that more frequent chocolate intake is linked to lower BMI - are intriguing,'' it added.