Dr. Beatrice Golomb, associate professor at the University of California, San Diego, and colleagues examined dietary and other information provided by approximately 1,000 adult men and women from San Diego, for whom weight and height were measured.
The findings were even more favorable than the researchers had hypothesized -- adults who ate chocolate on more days a week were actually thinner -- had a lower body mass index -- than those who ate chocolate less often.
The size of the effect was modest but the effect was "significant," and larger than could be explained by chance, despite the fact that those who ate chocolate more often did not eat fewer calories -- they ate more -- nor did they exercise more, Golomb said.
No differences in behaviors were identified that might explain the finding as a difference in calories taken in versus calories expended, Golomb added.
"Our findings appear to add to a body of information suggesting that the composition of calories, not just the number of them, matters for determining their ultimate impact on weight," Golomb said in a statement. "In the case of chocolate, this is good news -- both for those who have a regular chocolate habit, and those who might wish to start one."
The findings were published online in the Archives of Internal Medicine.