PORTLAND – Diners in Maine’s largest city may be the nation’s best in holding down their consumption of burgers and fries, a new report suggests.

The report by Sandelman & Associates, a California-based marketing firm that tracks restaurant industry trends, measured the frequency with which residents eat at fast-food restaurants.

Nationally, 42 percent of fast-food patrons go out at least a dozen times a month. But the rate in Portland was only 27 percent, the lowest among the 61 markets surveyed. The average Portland diner eats fast food about 11 times a month, the survey found.

The top market was Greenville, N.C., where 59 percent of residents are “heavy users” of fast-food chains and typically eat fast food 24 times a month.

The results for Portland are in line with the city’s rankings elsewhere. In recent years, Vegetarian Times and Outside magazine have named Portland as one of the country’s most health-conscious cities, even though Maine’s overall obesity rate is close to the national average and the highest in New England.

Some Portlanders who eat at fast-food places opt for lighter fare.

Karen Epp, general manager at the Arby’s in Portland, noticed that about 28 percent of her customers tend to order wraps and deli sandwiches compared to about 12 percent at stores in Auburn and Augusta.

But Portland public health officials say the fact that a quarter of those surveyed eat fast food regularly is still too much.

“This study gives us a national perspective, but we still have a lot of work to do,” said Tina Pettingill, manager of the health promotion program for the city of Portland.

Health attitudes may play a role in Portland’s consumption of fast food, but the overriding factor may be economics, said Jeff Davis, president of Sandelman & Associates.

Rising property values have discouraged fast-food chains from trying to enter the Portland market at the same pace as they have in other parts of the country, Davis said, and Maine’s relatively low population density makes it even less attractive.

The South and Southeast, home to the top 10 fast-food markets, have a wider selection of fast food because companies like the fact that land is plentiful and the population is booming, he said.