BOSTON—Calorie counts posted in chain restaurants often are inaccurate, and one in every five meals have at least 100 more calories than posted on the menu, according to a new study published in the Journal of the American Medical Association (JAMA).
Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University measured calories in 269 food items from nearly 50 fast-food and sit-down eateries in Boston, Indianapolis and Little Rock, Ark. Of the 269 items, 108 had energy contents at least 10 calories higher than the state amount and 141 had energy contents at least 10 calories lower. Nineteen percent of those with higher calorie counts were off by more than 100 calories.
They also found restaurants were most likely to underestimate low-calorie fare like soups and salads, and overestimate the calories in less-healthy choices like pizza and chips and salsa.
“On average, the food items measured 10 calories higher than the restaurants’ stated calories. That’s essentially accurate," said senior author Susan B. Roberts, PhD, director of the Energy Metabolism Laboratory at the USDA HNRCA. “However, 19% of food items contained at least 100 calories more than listed, which suggests calories for individual foods can be unreliable. One item contained 1,000 calories more than listed."
Lower calorie food items purchased in sit-down restaurants tended to have more calories than listed. Based on the data, the researchers were able to predict a sit-down restaurant item listed as approximately 300 calories, and therefore potentially suitable for weight loss or prevention of weight gain, could contain approximately 90 calories more than listed. Items often viewed as healthier from both sit-down and fast-food restaurants, such as salads and soups, tended to have more unreliable calorie listings.
Calories listed for fast food tended to be closer to laboratory measurements than the stated calories of items purchased in sit-down restaurants.
“Our data suggests the difference may be related to quality control in the kitchen," Roberts said. “Sit-down restaurants typically rely on workers to prepare food on-site, whereas most fast food is portioned out by factory machinery."