A US study at Texas Christian University suggests that menus displaying the exercise needed to burn calories in meals can help people consume less.
The research team found that diners given this extra information ordered and ate less calorific food than other customers.
Knowing it takes two hours of brisk walking to burn off a cheeseburger may be more of a warning than being told how many calories it contains, the researchers say.
The researchers now plan larger trials.
Dr. Meena Shah and Ashlei James divided 300 volunteers aged 18 to 30 randomly into three groups.
One received a menu without any calorie information, another menus with the calories displayed, and the third menus that showed both calories and the amount of exercise needed to burn them off.
All of the menus offered the same choice of food and drink, which included burgers, sandwiches, salad, chips, soft drinks and water.
- Calories (kcal) are a measure of the amount of energy in food
- Exercising burns calories
- An average man needs about 2,500kcal a day
- An average woman needs about 2,000kcal a day
- The values can vary depending on age and levels of physical activity
- The study assumed a brisk walking pace of 3.5 mph (5.5 km/h)
None of the volunteers was aware of the reason for the study and the researchers took into account hunger levels when interpreting their findings.
The group given the menus with the extra information about how much brisk walking would be needed to burn off the food ordered and ate much less than the group who had menus with no calorie information.
They consumed 100 fewer calories, on average, as a result.
Dr. Meena Shah said: “This is the first study to look at the effects of displaying minutes of brisk walking needed to burn food calories on the calories ordered and consumed.
“This study suggests there are benefits.”
The researchers say brisk walking is something nearly everyone can relate to.
“We can’t generalize to a population over age 30, so we will further investigate this in an older and more diverse group,” Dr. Meena Shah added.
They will present their findings at the Experimental Biology 2013 meeting in Boston.