Calorie labelling on menus and products has a “small” but “potentially meaningful” effect on people’s food choices, according to a review.
Calorie labels in supermarkets, restaurants and other food outlets led to an average reduction in the calories people selected and purchased of 1.8% – equating to 11 calories in a 600 calorie meal – or around two almonds, evidence from 25 studies suggests.
However, small daily changes in energy consumption could have meaningful effects if sustained long-term, and most adults tended to gain weight as they aged, the Cochrane Review noted.
A UK government report estimated that 90% of 20 to 40-year-olds in England would gain up to 9kg over 10 years, and that reducing daily energy intake by 24 calories per day – roughly 1% of the recommended intake for adults – would prevent this increase.
Senior author Dr Gareth Hollands, from the UCL Social Research Institute, said: “Our review suggests that calorie labelling leads to a modest reduction in the calories people purchase and consume.
“This may have some impact on health at the population level, but calorie labelling is certainly no silver bullet.
“Our previous version of this review from 2018 reported a potentially larger effect, but was inconclusive because there was significant uncertainty over the results. This update has reduced that uncertainty, and we can now say with confidence that there is very likely a real, albeit modest, effect.”
The review looked at evidence from studies involving more than 10,000 participants from high-income countries including Canada, France, the UK and the US.
Concerns remained about the possible impact of calorie labelling on people at risk of disordered eating, with the review noting a lack of data in the studies on possible harms, including mental health impacts.
Dr Hollands added: “Calorie labelling to reduce the calories that people consume remains somewhat contentious, both in terms of whether it has any effect, and whether potential benefits outweigh potential risks or harms.
“We can now say with considerable confidence that it does have a small but potentially meaningful effect on people’s food choices. Labelling may therefore have a useful role, ideally alongside a broader set of approaches that place more onus on industry rather than individuals, such as taxes, marketing restrictions and reformulation.
“However, we should not expect miracles, and any implementation of calorie labelling must balance the many potential positive and negative impacts of such policies.”
Professor Keith Frayn, from Oxford University, said: “In the real world, there is a hope of additional benefit as food suppliers reduce the calorie content of their products to make them more attractive to discerning consumers.
“There is some evidence for this occurring. So the true impact of calorie labelling over time is likely, if anything, to be greater than observed here.
“That makes calorie labelling a useful tool that will need to be employed along with other measures to help people reduce calorie consumption.”
