Do you ever wonder how some of the country’s restaurant chains figure out how many calories are in the meal you just consumed?
They send it to scientists to have it blown up.
Counting calories has taken on new importance since the U.S. Food and Drug Administration announced in November that restaurant chains with 20 or more locations must post calorie and nutrition facts on menus and menu boards.
Barbara Rolls, a professor in the nutritional sciences department and director of the food lab at Penn State, explained that when restaurant chains send their food to be tested, scientists put the food in a compartment and blow it up. Based on the energy given off by the food, its calories can be counted.
A calorie is a unit referring to the energy consumed by eating or drinking, as well as the energy used in physical activity.
Kitti Halverson, a nutrition research scientist at Penn State, has had experience in bomb calorimetry and the 20-minute process that measures this energy in a bomb calorimeter.
Only a small amount of the sample is needed, she said, so one gram of a pureed mix of all the ingredients in the food item is placed in a container with mineral oil or another highly flammable substance. The container is put in the bomb, attached with a small fuse, pumped full with a set amount of oxygen and placed underwater.
The temperatures of the water and the bomb are taken, and the calorimeter lights the fuse and explodes the food, consuming the sample and accelerant. The calorimeter then takes the two measured temperatures, subtracts the heat of the fuse and accelerant, and uses the remaining heat to determine the heat energy — the calories — of the food.
“Americans eat and drink about one-third of their calories away from home, and people today expect clear information about the products they consume,” FDA Commissioner Margaret Hamburg said at the time of the announcement.
“Having calorie counts in restaurants is beneficial in helping customers when comparing foods on the menu, but calorie counts are also deceiving,” Rolls said. “Usually, when there is a calorie count on the menu, the add-ons are not included, so the costumer is really consuming more calories than they are aware of.”
Affected restaurants will have to post the calorie count of a menu item next to its name and price on menus and menu boards. To help customers put the calorie count in perspective, both must include the fact that the calories in the food items are based on a 2,000-calorie diet.
Panera Bread has had calorie counts and nutrition facts available for four years; it was the first restaurant chain to put calorie counts on menus. Its customers also can find calorie counts and nutrition facts on its website.
“Being able to keep track of your calories is a great privilege for a restaurant to provide their customers,” said Roberta Guthery, a resident of Columbus, Ohio, who was visiting. “I actually sought Panera out in State College because I knew they have their calories posted. Being able to keep track of your calories gets harder the older you get and Panera allows me to do so.”
McDonald’s has taken similar steps, but employee Shaina Golembeski said, “I don’t think having the calorie counting has had an effect in a place like this. We have the facts posted on the menu, but our customers will still order two Big Macs and a large fries.” She works at the McDonald’s restaurant on East College Avenue.
“Whenever I come here, I know what I’m going to get and the calories don’t affect my decision,” said Jerry Kroboth, a Penn State student who was at the same McDonald’s. “I feel like in a restaurant like this, knowing the calories doesn’t make a difference.”
In addition to calorie counts posted on their menu boards, Panera Bread and McDonald’s have nutrition facts, including fats, carbs, protein, sodium and cholesterol, available upon request and on their websites.
A number of other chain restaurants in the area — Red Lobster, Cracker Barrel, Olive Garden, TGI Fridays, Chili’s, IHOP, Outback Steakhouse, Texas Roadhouse and Applebee’s — have not yet put the information on menus in their restaurants but have listed calories and nutritional facts of menu items on their websites.