CHICAGO — A survey of restaurant patrons conducted by Mintel International Ltd. showed that 41% think eating healthfully at a restaurant is more expensive than eating less healthy meals.

The market research firm pointed out that during the recession U.S. restaurant sales have been hit hard and food service operators have tried to maintain sales and attract new customers by promoting value. Missing from many of the value menus, according to Mintel, are dishes featuring fresh vegetables, fruit and other nutritious ingredients.

“The perception that healthy foods are also higher priced is a challenge for restaurant operators, who are under their own pressure to add healthier menu items, not only from consumers but also the government,” said Eric Giandelone, director of Mintel’s Foodservice research unit.

The food service survey also showed less than half of the customers surveyed thought that healthy meals rate higher than average meals in flavor, satiation, appearance and taste. They also believe that 510 calories is the average calorie count a meal perceived as healthy should contain.

Mr. Giandelone said the disconnect between healthy and hearty is the source of the problem.

“People believe they will be sacrificing flavor and the expectation of a satisfying meal,” he said. “Since the idea of freshness is so closely tied with good health, restaurant operators can use fresh ingredients as a signal of high quality and high taste, while an emphasis on calories still allows for a focus on satiety and flavor.”