• Health

Dieters Beware: Calorie Counts Are Frequently Off

4 minute read
Jeffrey Kluger

When you buy a car with a six-cylinder engine, you expect to get six cylinders. When you buy a dress in a size 10, you expect a size 10. And when you buy a burger at a fast-food joint that’s listed on the menu as containing 500 calories, you jolly well expect 500. But you may be getting a lot more than that. The same may be true of the omelet and the pasta you get at a sit-down restaurant — and of the frozen dinner with the label you read so carefully before you tossed it in your supermarket basket and took it home.

(See the 10 worst fast-food meals.)

According to a new study published in the Journal of the American Dietetic Association, prepared foods may contain an average of 8% more calories than their package labels own up to and restaurant meals may contain a whopping 18% more. Worse still, as far as Food and Drug Administration regulations are concerned, that’s perfectly O.K.

(See the top 10 new diet books.)

The findings are the result of work conducted by Susan Roberts, professor of nutrition at Tufts University, and Jean Mayer, of Tufts’ USDA Human Nutrition Research Center on Aging. It was Roberts who initiated the study, and it was her own struggles with weight that got her started. Author of the book The Instant Diet, she was working on new recipes for the paperback version (retitled The “i” Diet) and, as was her practice, used herself as a guinea pig. As a rule, she lost weight on the menu plans she recommended to readers, but when she redeveloped some of the meals using what were supposed to be calorically equivalent supermarket or restaurant foods, the pounds stopped dropping off. Just as suspiciously, she always felt full.

“I went into the lab and said, ‘I don’t believe these calorie numbers,’ ” she says. “So we went out and started collecting foods and sampling their contents.”

(See 10 myths about dieting.)

In all, she studied 29 restaurants and 10 frozen-food products, taking care to select foods that dieters would be likely to choose, which meant that they were said to contain 500 calories or fewer and that, in restaurants, they were among the lowest-calorie items on the menus. Back in the lab, Roberts’ tests revealed the high-calorie truth, and the numbers were even more troubling than ordinary dieters would appreciate.

No one would deny that the 18% calorie overload on restaurant menus is a problem. The additional 8% in frozen foods sounds less serious; in a 500-calorie entree, after all, 8% adds only 40 calories. That, however, is in a single meal. Over the course of a year, consuming just 5% more than you need in a 2,000-calorie diet can mean a 10-lb. weight gain. “The 18% and 8% figures are just what you need not to lose weight,” says Roberts.

(See the best pictures of 2009.)

In her book, Roberts reformulated menus to correct for the problem, but there’s a big, fattening world out there that isn’t taking such remedial steps. Federal regulations are strict about the accuracy of the net weight of a package of prepared food, which must be at least 99% of the advertised weight. When it comes to calories, the count can be a far bigger 20% off. The Federal Government plays no role in checking the calorie claims in restaurants, which means it’s up to the states to handle the job — with the predictable patchwork results. “It really is the Wild West when it comes to this,” says Roberts. “And when state inspectors do visit, they have other issues to worry about — like making sure there are no mouse droppings in the kitchen.”

(See how some people are getting paid to lose weight.)

Even a restaurant whose published numbers are accurate down to the last calorie still may not give customers a truly realistic sense of what they’re consuming. Every item on the menu, after all, has a separate calorie count, but many people pay attention mostly to the main course, piling on side dishes as something of an afterthought. Five of the restaurants in the survey even provided side dishes at no extra cost, and these added up to an average of 471 extra calories — exceeding the 443-calorie average of the entrees. “What they should be telling consumers,” Roberts says, “is what actually comes on the plate.”

That seems like a fair requirement. It’s hard enough to maintain your weight in the all-you-can-eat buffet that is the modern world. The least the health-conscious should be able to expect is a fair reading of what they’re eating — and they can take responsibility from there.

See the top 10 food trends of 2008.

See a special report on the science of appetite.

More Must-Reads from TIME

Write to Jeffrey Kluger at jeffrey.kluger@time.com