July 19, 2011 -- Most posted calorie counts for restaurant foods are generally accurate, but there can be big discrepancies, especially at sit-down restaurants, according to a new analysis.
The study shows that overall the posted calorie counts for foods at 42 fast-food and sit-down restaurants were within 10 calories of their actual content. But 19% of foods contained 100 calories -- or more -- more than their posted calorie count.
In general, researchers found more discrepancies in calorie counts in foods served at sit-down restaurants than fast-food establishments.
The study is published in the Journal of the American Medical Association.
The largest calorie count inaccuracies of foods that contained significantly more energy than stated were found among carbohydrate-rich side dishes, soups, salads, and desserts at sit-down restaurants.
"Although not typical, 1 side dish contained an excess of 1,000 kcal/portion than the stated energy amount of 450 kcal/portion, which is an amount that is nearly half the total daily energy requirement for most individuals," write researcher Lorien E. Urban, PhD, of Tufts University in Boston, and colleagues.
Unfortunately for people trying to count calories, the results also showed entrees at sit-down restaurants with a lower stated calorie count, like salads, which would be most appropriate for people trying to lose weight or prevent weight gain, often contained more calories than stated.
In contrast, some foods with higher stated calorie counts -- such as pizza, sandwiches, and meat -- often had fewer calories than stated.
Researchers say variation in portion size at sit-down restaurants may be responsible for much of this discrepancy in calorie counts of individual foods.
Comparing Calorie Counts
Researchers say foods purchased from restaurants account for about 35% of the daily calorie intake of Americans.
Experts say controlling and reducing energy or calorie intake by selecting foods lower in calories is a critical step in combating the obesity epidemic in the U.S.
In their study, the calorie counts of 269 foods items from seven fast food and seven sit-down restaurants across three states were measured via laboratory analysis and compared to their posted calorie counts published by the restaurants.
The results showed that overall there were no major differences between the stated and measured calorie counts for restaurant foods, and the stated calorie counts measured an average of about 10 calories per portion higher than the measured calorie count.
"However, the stated information of individual foods was variable and 19% of individually tested foods contained energy contents of at least 100 kcal/portion more than the stated energy contents, an amount that has been projected to cause 5 to 15 kg of weight gain per year if consumed daily," write the researchers.
In a second analysis, researchers remeasured the calorie count of the 13 foods with the biggest discrepancies between their posted calorie count and actual content. The results showed these foods contained an average of 273 calories more than their posted calorie counts, a 48% discrepancy.
Researchers say their findings have implications for pending implementation of laws requiring more restaurants to list the calorie counts of their menu items.
"Although our study showed that stated energy contents in restaurants are relatively accurate on average, thus supporting greater availability of this information, projected benefits for preventing weight gain and facilitating weight loss are likely to be reduced if restaurant foods with lower stated energy contents provide more energy content than stated," write the researchers. "Additional portion control in restaurants has the potential to facilitate individual efforts to reduce energy intake and to help resolve the national obesity epidemic."