Menus displaying the exercise needed to burn calories in meals can help people consume less, a US study suggests.

Diners given this extra information ordered and ate less calorific food than other customers, a team at Texas Christian University found.

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.

They now plan larger trials.

"While displaying the amount of exercise needed to burn calories is an interesting idea, there's more to a heart-healthy diet than calorie counting"

End Quote Victoria Taylor British Heart Foundation
Researchers 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 3.5mph (5.5km/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 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.

Calorie counting
"We can't generalise to a population over age 30, so we will further investigate this in an older and more diverse group," Dr Shah added.

They will present their findings at the Experimental Biology 2013 meeting in Boston.

Victoria Taylor, senior dietician at the British Heart Foundation, said clearly signposting healthy options and nutritional content helped people make informed choices when ordering food.

But she added: "While displaying the amount of exercise needed to burn calories is an interesting idea, there's more to a heart-healthy diet than calorie counting.

"Restaurants can also take steps to make meals healthier by serving appropriate portion sizes and reducing the amount of salt, saturated fat and sugar in their dishes.

"Whether eating at home or dining out, a balanced diet with plenty of fruit and veg is the best way to protect your heart."