Say you’re at a fast-food place ordering a crispy chicken sandwich. Would seeing that it has 620 calories give you pause?

What if you saw that it might take a 6.5-mile walk to burn it off?

“Calorie information alone is so out of context,” says Anthony Viera, a public health researcher and doctor at UNC Family Medicine. To make sense of 620 calories, you have to think about what else you’re eating in that meal, what you’re having for dinner later on, and how that compares with your daily calorie needs. All this while you’re rushing through a fast-food line.

Calories on menus

Back in 2006, New York City mandated that chain restaurants with 15 or more locations, excluding restaurants where you order at the table, add calorie counts to menus. Now, restaurants nationwide will have to start doing the same, as directed by the Patient Protection and Affordable Care Act.

In short, just sticking calorie information on the menu above the counter doesn’t work, Viera says. When his team reviewed research about adding calorie information to menus in restaurants, school cafeterias, and test menus in the lab, they realized that letting people see how many calories are in food has little to no effect on what they order. So Viera decided to try something different: alongside the calorie figure, show how long it’ll take to walk that sandwich off.

Viera, who counsels many of his patients on weight loss, wasn’t surprised to find that calorie information alone doesn’t have much effect on fast-food customers. Many people, he says, overestimate how many calories they should eat. “The message we’ve heard is everything based on a 2,000 calorie diet,” he says. “But depending on your expenditure, 2,000 calories may be overdoing it by quite a bit.” Viera is often surprised by how long it takes him to burn just a few hundred calories on the treadmill.

So he and his team made up a test menu that shows calorie information next to food items and the number of miles or minutes a 160-pound person would have to walk to use up the calories. The foods, such as hamburgers, french fries, and milkshakes, were composites of items from popular fast-food places. The team made an online survey asking people to imagine they were at a fast-food restaurant and pick what they would order. About 800 UNC employees participated.

The average person who picked a meal without nutritional information chose items adding up to 1,020 calories. With calorie information, people chose about 100 calories less—the same as when they saw a label telling them how many minutes it might take to burn it off. But when people saw how many miles they might have to walk to use up the calories, they chose only about 820 calories.

Sunaina Dowray, a med student and the study’s lead author, takes a guess at why: “Minutes walked might seem more accessible to somebody who doesn’t exercise much, but a mile can seem really daunting.”

A hamburger might take 2.6 miles of walking at a 30-minute-mile pace to burn off; add 4 miles for a medium French fry and another 1.5 for a small soft drink. Altogether, that’s 780 calories and about 8 miles of walking if you’re not going to use up those calories in your daily activities.

The point isn’t to get people to do a mathematical calculation in the fast-food line. “We’re not necessarily saying, ‘If you eat this, go and walk three miles,’” Viera says.

“It’s a way for people to compare items and think, ‘Okay, if I’m not doing that much activity, maybe I need to choose something with fewer calories.’”

Anthony Viera is an associate professor and Charles B. Wilkerson, MD ‘06 Distinguished Scholar in the Department of Family Medicine and director of UNC’s MD-MPH Program. He coauthored the review of research on calorie information in menus with Jonas Swartz, then an MD-MPH student at UNC, and Danielle Braxton, a graduate student in nutrition. With Sunaina Dowray, they coauthored the study of physical activity menu labeling, which appears in the March 1, 2013, issue of the journal Appetite. It was funded by UNC-Chapel Hill’s University Research Council. As a next step, Viera will seek funding to test their physical-activity menus in a real-world setting such as a hospital cafeteria.