Calorie labels on menus have no effect on dietary habits because people ‘don’t understand what the numbers actually mean’, a study suggests.
In April 2022, the government introduced a policy in England that orders the use of calorie labels by all food outlets with more than 250 employees.
It was hoped that by providing the number of calories next to each dish, consumers would think twice about what they eat when they visit takeaways, cafes and restaurants to help battle soaring rates of obesity.
But the policy has had no significant effect on the number of calories people buy or consume, a study suggests – and it could be because people still don’t understand exactly what the numbers mean.
Researchers from the University of Liverpool conducted two surveys before and after the implementation of the law to see whether it led to any behaviour changes.
They collected data from more than 6,500 people of all ages who had purchased food from more than 300 outlets including pubs, restaurants, cafes, fast food outlets and entertainment venues.
Analysis revealed that after the law was implemented, people were more likely to notice and use the calorie labelling system.
They were also more likely to accurately estimate the calorie content of their meals.
Researchers found awareness of calories in food was greater in women, and in those who were better off.
However, there was no significant difference in how many calories were purchased or consumed.
On average, people ate around 18 fewer calories after the policy was implemented — the energy equivalent of about nine grapes.
Lead researcher Dr Megan Polden said: ‘The introduction of mandatory calorie labelling alone was not associated with significant dietary changes in out-of-home food settings.’
The findings, published in the journal Nature Human Behaviour, revealed that awareness and use of the calorie-labelling system were higher among women, older adults and those who are better-off.
People were also more likely to notice calorie labels when ordering from pubs – possibly due to spending more time reviewing the menu.
Reasons for their findings could be that a lot of places still don’t implement calorie labels on menus and people still don’t understand how calories work, the team suggested.
‘We know that many businesses have not been providing calorie labelling as recommended and some businesses have not provided any calorie labelling at all, which of course may explain our results,’ Professor Eric Robinson, who also worked on the study, said.
‘Our results may also indicate that a combination of strategies…such as public education on calorie intake and clearer labelling, could be necessary to support healthier consumer choices.’
The study states that a potential barrier to the use of calorie labelling ‘may be a lack of public understanding of the kcal information presented.’
Commenting on the findings Professor Amanda Daley, director of the Centre for Lifestyle Medicine and Behaviour at Loughborough University, said: ‘One problem with calorie labelling is that it just provides numbers on a page, without any context for the public to understand what the numbers actually mean when they are making decisions about food.’
She added that the study was based on self-reported data rather than actual transactions or information about the food consumed, so this is ‘important to consider when interpreting the results’.
Tom Sanders, Professor emeritus of nutrition and dietetics at King’s College London, said: ‘The takeaway finding from this study is that on its own mandatory calorie labelling is an ineffective public health measure to prevent obesity.
‘This would support the view that calorie labelling alone does not motivate people to change their dietary habits.
‘However, calorie labelling is useful for individuals who are motivated.
‘Mandatory nutrition labelling has also helped computer programmes and apps provide accurate and up to date estimates of nutrient intakes using product bar codes which is useful for nutritionists, dietitians and motivated individuals.
‘Consequently, it would be a backwards to step to abolish mandatory calorie labelling for the out of the home food sector.’
