menu-cp-4212600

New York City approved a law in 2008 requiring large chain restaurants to display calorie counts on or near their menus. ((Mary Altaffer/Associated Press))

The food at many popular U.S. chain restaurants and in the freezer section of the supermarket may contain a lot more calories than advertised.

A U.S. study of 10 chain restaurants, including Wendy's and Ruby Tuesday, found that the number of calories in 29 meals or other menu items was an average of 18 per cent higher than listed.

And frozen supermarket meals from Lean Cuisine, Weight Watchers, Healthy Choice and South Beach Living had eight per cent more calories than the labels said, according to the study, published in this month's Journal of the American Dietetic Association.

The researchers and other experts aren't accusing restaurants and food companies of trying to deceive customers. They said most of the discrepancies can be explained by variations in ingredients, portion sizes and testing methods. For example, the teenager behind the counter might have put too much mayonnaise on one sandwich.

Still, "if every time you eat out, you get a couple of hundred calories or more than you think, that can add up really easily," said lead researcher Susan Roberts, a professor of nutrition at Tufts University. "There's a big drumbeat for people putting calories on menus, but that's only useful if the calories are right."

Packaged food tests

Marion Nestle, a professor of nutrition at New York University who was not involved in the study, said she was not surprised by the findings. People might think nutrition labels are scientifically precise, but they are mostly ballpark figures, she said.

"It would never occur to me that the calories posted on menu boards are anything close to reality," Nestle said.

The study showed most of the packaged food tested fell within the 20 per cent margin of error allowed by the U.S. Food and Drug Administration.

Some items, like Domino's large thin-crust cheese pizza, came in low. It had one-third fewer than the reported 180 calories per serving.

Wendy's Ultimate Chicken Grill was found to have nine per cent more calories than the reported 320. Ruby Tuesday's baked potato with butter and sour cream came in on target, but researchers measured three per cent more calories in McDonald's McChicken sandwich, which is said to have 360 calories.

Wendy's spokesman Bob Bertini said: "Since our food is prepared to order by restaurant teams, there can be small variances in the calorie count. For example, one sandwich might have a bit more mustard or ketchup. The next sandwich, the customer might choose to leave off the lettuce and tomato."

Portion sizes vary

As the nation grapples with staggering obesity rates, local and state officials around the U.S. have considered requiring chain restaurants to post nutrition information about their food. New York City, neighbouring Westchester County, and King County in Washington state already have such regulations.

A private member's bill in Ontario would require fast-food restaurants that do more than $5 million business to limit trans fats and provide nutrition labels on menus, and British Columbia restricts trans fat in foods prepared and served at restaurants.

Despite the inaccuracies, Nestle said she believes nutrition information is useful. But she said people need to realize that a bagel listed at 303 calories could contain dozens more, or dozens fewer.

Researchers used a calorimeter to test food from Boston-area restaurants and grocers. They compared their results with calorie counts available from the companies in 2007 and 2008.

In a statement, a Denny's spokeswoman said variations in portion sizes can occur from restaurant to restaurant. The company also said it uses local vendors for bread, dairy and produce, each of which could have different product formulations and sizes.

Denny's questioned the study's contention that its grits and butter had three times the 80 calories listed on the menu — the largest fluctuation of all foods tested. Denny's said the researchers tested a 270-gram serving instead of the 113-gram one used in its own analysis.

"It would bother me if I counted on it to make my decision on what to get," Audrey Ledford, 55, of Torrance, Calif., said after having coffee with her son at a Los Angeles Denny's. "It should be correct."