Researchers found labels which only show how many calories a food item contains has little or no impact on people’s behavior.

However, when the 220 participants were told they would have to jog for 40 minutes to burn off a chocolate bar or 20 minutes for a muesli bar, it deterred them from making unhealthy purchases.

Not only were people more likely to exercise when they saw such labels, they also felt more guilty, according to the study.

Study author Michelle Bouton said exercise labels could have a wide ranging impact for food-labelling standards and educating New Zealand consumers about their food choices.

But Healthy Food Guide nutritionist ClaireTurnbull told the New Zealand Herald exercise-labelling could oversimplify nutritional information.

“The problem again is it depends on how heavy you are, whether you're a man or a woman [and] how fast...you walk,” she said.

"It still doesn't tell you how much fat is in the product."