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 a population 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 its 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.
A normal BMI is typically 18.5 to 24.9, while people who figure lower are considered underweight and those above 25 are overweight.
"Adults who consumed chocolate more frequently had a lower BMI than those who consumed chocolate less often," said the study led by Beatrice Golomb and colleagues at the University of California San Diego.
"Our findings - that more frequent chocolate intake is linked to lower BMI - are intriguing," it added, calling for more detailed research and perhaps a randomised clinical trial of chocolate's metabolic benefits.
While the research stopped short of establishing a reasonable or beneficial limit for chocolate-eating, experts urged moderation.
"Before you start eating a chocolate bar a day to keep the doctor away, remember that a chocolate bar can contain over 200 calories which mostly come from saturated fats and sugar," said Nancy Copperman, director of Public Health Initiatives at the North Shore-Long Island Jewish Health System in New York.
"Consider limiting your chocolate fix to a one ounce (28 grams) portion of dark chocolate or adding cocoa powder which is very low in fat to your food once a day," said Copperman, who was not involved in the study.
Chocolate's benefits are rooted in antioxidant polyphenols which can improve blood pressure, and also help lower cholesterol levels and blood sugar.
Other studies have even linked chocolate to a lower risk of death by heart attack.
Chocolate's curious ability to improve heart health is usually considered as part of a lifestyle that includes exercise and moderation in diet, according to Suzanne Steinbaum, director of women and heart disease at Lenox Hill Hospital in New York, who was not involved in the study.
"We have seen in multiple studies the benefits of chocolate, and yet again, we see as part of an overall healthy lifestyle, chocolate does not add to weight gain, but in fact, might help control it," she said.