Nutrition labels are inconsistent and confusing, and governments around the world are looking for ways to make them easier to understand.
A novel approach has come out of a small New Zealand study which found that people were less likely to consume an energy-dense snack food when its label specified how much exercise it would take to burn off its calorie content. The label on a chocolate bar, for example, might say it would take 40 minutes of running to burn off its calorie content.
It also found that labels with only calorie information had little or no impact on people's behaviour.
The study of 220 people was undertaken as part of an honours dissertation in marketing by a University of Canterbury honours student, Michelle Bouton.
Having the energy content of a product expressed in terms of exercise ''increased the likelihood of having higher feelings of guilt after consumption and was more likely to stop [the participant] consuming the chocolate bar,'' Ms Bolton said.
Furthermore, ''80 per cent of participants wished that nutritional food labelling was easier to under-stand and 55 per cent said they had no idea what 1700 kilojoules was in calories,'' she said.
Ms Bouton's findings are not new. A review commissioned last year by the Australian Food Grocery Council, found ''the assumption that front-of-pack labelling drives consumer behavioural change, leading to improved dietary patterns, is inconsistent and inconclusive''.
Kellie Bilinksi , a spokeswoman for the Dietitians Association of Australia, agrees that for many people, nutrition labels are nonsensical. ''In addition to nutrition labels [exercise information] might be useful as it puts the information into perspective and might deter people.''
But she points out that such a system has the potential to be misleading, too, because energy expenditure is not one size fits all. It is affected by factors including body weight, gender and metabolism.
Another key problem with existing food labels is that the serving size of a product is determined by the food manufacturer.
This means many manufacturers can ''frame'' a product to appear healthier by making the standard serving size smaller. This sneaky marketing means nutrition labels ''can lead even the most health-conscious consumers astray, if they don't 'do the maths',''" says a professor in marketing, Donald Lichtenstein, the lead author of a study that has come out of the University of Colorado.
The Australian consumer watchdog Choice recently analysed the serving sizes across a range of products. It found that for 40 corn chip products checked, the serving size ranged from 25 to 100 grams. For 32 popcorn products, the serving size ranged from 13 to 100 grams. For 33 plain adult cereals, the serving size ranged from 10 to 55 grams.
As a result of the analysis, Choice recommended a traffic light system, which would give a food a red, yellow or green light. The system is set to be adopted in Britain next year. The US is proposing a similar system that offers ratings as well as a colour code. However, the Choice recommendation was rejected by the federal government on the basis that there was insufficient evidence to prove its effectiveness.
A government-facilitated working party has since been established to look into the matter further. The group, chaired by the secretary of the Department of Health and Ageing, Jane Halton, is not considering exercise labels. Public health groups support the traffic light system, but industry is strongly against it. A star system, similar to the energy star system currently on whitegoods, shows some promise.
Support for a star system comes on the back of the Blewett review of food labelling last year, which recommended changes in labelling to encourage healthy eating and population health. It has been recommended in the US by the Institute of Medicine. This system would provide a nutrient profile score measuring overall quality of the food.
The working party won't comment further at this stage. It will meet again in December.
The story Work-off factor a weapon in encouraging healthy eating first appeared on The Sydney Morning Herald.