Jonathan Chrispin, M.D., reports:

A new study suggests snacking on chocolate could help fight weight gain.

Researchers from the University of California, San Diego, asked more than 1,000 healthy men and women about their chocolate consumption as well as the rest of their diet and physical activity. Those who ate chocolate more often during the week had a lower body mass index or BMI, a measure of body fat content. In fact eating, "chocolate five times a week was associated with a decrease in BMI of 1 kg/m2," the researchers reported.

"The study is provocative and confirms what we have been calling the chocolate/obesity paradox: Despite chocolate's high caloric load, its regular intake does not result in weight gain," said Dr. Franz Messerli, Director of Hypertension program at St. Luke's-Roosevelt Hospital in New York, who was not involved in the study. "Thus, to put it pointedly, chocolate could be called a lazy man's exercise."

People who ate more chocolate consumed more calories and saturated fat, and did not exercise any more than those who ate chocolate less, according to the study. Yet they still had a lower BMI.

Previous studies suggest dark chocolate can lower blood pressure, bad cholesterol and even the risk of diabetes. This study, however, did not distinguish between dark and milk chocolate.

"This is a rather vague study, not specifying the kind of chocolate, so it only adds to what we know in general terms,"  said Dr. David Katz, director of the Yale University Prevention Research Center. "We have strong evidence of net cardiovascular benefit from routine intake of moderate amounts of dark chocolate."

The best quantity of chocolate is also unclear, as the study only examined the frequency of consumption.

Katz said he worries the benefits of snacking on chocolate might be offset by the risks of weight gain over time.

"This study suggests that is not the case," he said.

Some experts say the evidence for chocolate's health benefits is strong enough to recommend the odd indulgence.

"I've often told patients who love chocolate that it's OK to include [chocolate in their diet]," said Keith Ayoob, director of the Nutrition Clinic at Albert Einstein School of Medicine in New York. "Best is dark chocolate, and best is to keep it to about an ounce per day. That amounts to only about 150 calories - a lot less than any pastry they'd eat."

How could a treat filled with sugar and fat fight weight gain? It might be due to the high concentration of epicatechin, a flavonoid found in cocoa, tea, blueberries and grapes.

"Epicatechin from cocoa causes greater control over food urges and is more satisfying than other treats," said Dr. Peter McCullough, a cardiologist at St. John Providence Health in Warren, Mich. "Higher cocoa chocolate is relatively low in sugar and the fatty acid in chocolate products is probably not as worrisome as other fats. On the whole, a little superior quality chocolate is good to add to the diet of those trying to lose weight."

Experts agree more research is needed to clarify how chocolate fits in with weight control. But in the meantime, a little chocolate certainly won't hurt.

"Dark chocolate is a health indulgence. If you choose wisely, and 'dose' moderately, it can fit into a healthful diet and not cause weight gain," Katz said. "What is clear is that dark chocolate stands out as an example of a food we love that has considerable potential to love us back."

Dr. Chrispin is an internal medicine resident at Johns Hopkins Hospital in Baltimore.