LABELLING food and drink with the amount and type of exercise needed to burn off the calories could be a more effective method of curbing obesity, researchers have said.

They said the current system of food labelling by calorie and nutrient content is poorly understood, and there is limited evidence that it is encouraging consumers to make healthier purchases.

In a paper published in the Journal of Epidemiology & Community Health, the researchers from Loughborough University said labelling by exercise instead had the potential to cut daily calorie intake per person by an average of up 195 calories.

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Physical activity calorie equivalent or expenditure (PACE) food labelling aims to show how many minutes or miles of physical activity are needed to burn off the calories in a particular food or drink.

For example, eating 229 calories in a small bar of milk chocolate would require about 42 minutes of walking or 22 minutes of running to burn these off.

The UK Royal Society for Public Health has already called for PACE labelling to replace the current system, but to date, there has been little strong evidence to back this stance.

The Loughborough University researchers analysed 15 randomised controlled trials comparing PACE to other forms of food labelling, or no labelling.

They found that when PACE labelling was displayed on food and drink items and on menus, consumers took in 65 fewer calories per meal, on average.

PACE labelling was also associated with the consumption of 80 to 100 fewer calories than no food labelling, or other types of labelling.

Based on their findings, and average consumption of three meals a day plus two snacks, the researchers suggest that PACE labelling might potentially slice almost 200 calories off a typical individual's daily intake.

However, they caution that the studies were small and not carried out in real life settings, such as restaurants and supermarkets.

Nevertheless, they conclude that PACE labelling "shows some promise in reducing the number of kilocalories [calories] selected from menus, as well as the number of calories and the amount of food (grams) consumed.”

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The evidence shows that even a relatively small reduction of around 100 calories per day, combined with a sustained increase in physical activity, is likely to be good for health and could help curb obesity at the population level.

They add: “PACE labelling is a simple strategy that could be easily included on food/beverage packaging by manufacturers, on shelving price labels in supermarkets, and/or in menus in restaurants/fast-food outlets.

“Public health agencies may want to consider the possibility of including policies to promote [it] as a strategy that contributes to the prevention and treatment of obesity and related diseases."