Although fast food restaurants display calorie listings, researchers suggest that the listings don’t do a stellar job of assisting consumers with proper health food options.

Elizabeth Gross Cohn, assistant professor at Columbia University, along with her colleagues examined the calorie counts for 200 food items on the menus of fast-food chains in a neighborhood in New York City.

“Although most postings were legally compliant, they did not demonstrate utility,” said the authors. “Menu postings for individual servings are easily understood, but complex math skills are needed to interpret meals designed to serve more than one person. In some items, calories doubled depending on flavor, and the calorie posting did not give enough information to make healthier selections.”

The study consisted of volunteers paired in groups of two, and each couple searched for and entered national restaurant chains throughout the neighborhood. Each group was also given digital cameras.

A sum of 70 menus and menu boards from 12 restaurant chains were photographed, and 200 food options were rated, using a method of “practical utility” that researchers developed to calculate — (1), which equated to a single serving, and (2) the amount of calories in a single serving. The numbers were then combined with current FDA guidelines to create a “seven-item menu rate tool.”

Researchers confirmed that most of the fast-food chains displayed inadequate information because they listed individual food items but served mainly combination meals, thus making it difficult to properly measure the calorie intake.

A prime example was at a fast food chicken establishment that listed a bucket of chicken at 3,240 to 12,360 calories, but the menu board didn’t list the number of pieces of chicken in a serving size.

Although the authors only limited their research only to one neighborhood, and didn’t consider actual food purchasing habits, they still believe that their findings show the need for clearer and easier to calculate calorie information, especially among lower-income neighborhoods, and varying levels of literacy.

“As further legislation is developed, we support the FDA in their commitment to having menu boards that are useful at all levels of literacy,” they wrote.

As of March 2010, federal law requires restaurants with 20 or more locations to publicly display calorie and nutritional information for each of their menu items.