A new study has argued that food labelling should indicate how much physical activity is required to burn off the calories in the product - not just the number of calories.
The new research, conducted by Professor of Behavioural Medicine Amanda Daley and her colleagues at Loughborough University, UK, is to be presented at this year's International Congress on Obesity, which will be held in Melbourne from October 18-22.
The findings suggest that displaying the amount of physical activity required to burn off the calories in the product would be easier to understand than existing labelling, and may be a more effective way to help consumers avoid unhealthy choices.
To conduct their research, the scientists asked 2668 people to compare the UK's established 'traffic light' system of labelling with new 'physical activity calorie equivalent' (PACE) labelling. The participants were asked which labelling they preferred, which was easier to understand, which caught their attention the most, and which was more likely to help them avoid high-calorie foods.
The 'traffic light' labelling system is an interpretive label that utilises a simple colour scheme to indicate relative levels of total fat, saturated fat, sugar and salt in products, with green indicating low levels, amber indicating moderate levels and red indicating high levels.
Alternatively, PACE labelling offers a different approach by providing the nutritional information with an interpretation of what the calorie content of the product looks like in terms of energy expenditure. It aims to illustrate how many minutes of physical activity are equivalent to the calories contained in food and drinks - for example, "the calories in this cake require 90 minutes of walking to burn off."
Overall, slightly more participants preferred the existing 'traffic light' system to PACE labelling (43 percent vs 33 percent), but more participants found PACE easier to understand (41 percent vs 27 percent) and felt it was more likely to catch their attention (49 percent vs 31 percent).
Respondents who were physically active at least three to four times per week and five or more times per week were 42 percent and 45 percent more likely respectively to say that PACE would catch their attention over traffic light labelling, compared with participants who exercised twice a week or less.
A greater number of participants also thought PACE was more likely to help them avoid high-calorie food than traffic light labelling (44 percent vs 28 percent). Those aged 65 years and older were 40 percent less likely to prefer PACE, compared with the youngest group (18 to 44).
Additionally, the study found there was a preference for PACE labelling to be placed on discretionary foods; for example, chocolate and cakes rather than 'everyday' items like bread, pasta, fruit and vegetables.
There was also a preference for PACE to be displayed in fast food outlets, supermarkets, vending machines and on takeaway and online menus; all locations that typically sell calorie-dense food and drink.
"Nutritional labels support people to make food choices and traffic light labelling is the UK standard. However, many people do not understand the meaning of kilocalories (kcals or calories) or grams of fat displayed on food labels, and often underestimate the number of calories when labelling is not provided," Professor Daley explained.
While there is some evidence that PACE labelling may be effective in reducing calorie consumption, there is a lack of evidence about the views of the public concerning its potential implementation, the scientists noted.
"Our findings highlight that PACE labelling is a potentially important policy-based approach to strengthen current approaches to food labelling. The next steps are to test whether PACE labelling reduces the purchases of high calorie foods and drinks in different food settings such as restaurants, vending machines, coffee shops and pubs," the team concluded.
Professor Daley's team is about to begin trials of PACE labelling in vending machines and cafeteria settings.
