Nutrition labels on the front of food packaging should be made mandatory in the UK, according to a consumer champion.
Which? called on the Government to make the change amid what it described as an “obesity crisis”.
A “better approach” is needed to help people make healthier choices, it said.
It comes after research by the group found shoppers prefer traffic light labelling, although they said it could be improved with more prominent placing and increased size.
Traffic light labelling on food packaging was introduced in 2013 and uses green (low), amber (medium), and red (high) colours to show fat, saturated fat, sugar, and salt content, plus calories.
The system is not mandatory in the UK, although it is voluntarily used by major manufacturers and retailers.
However, according to Which? the system is used inconsistently.
It claims some shops do not include traffic light labelling, or provide it without colour coding.
Research by Which? captured insights through the mobile phones of more than 500 shoppers to find out how the traffic light system is working for customers.
A third (33%) said that the nutrition label was the first thing they looked at on the front of a pack.
People most used the traffic light system when choosing snacks (56%), dairy products (33%) and breakfast cereals (27%).
Almost half (47%) said they found this labelling easy to understand.
In focus groups, the traffic light system was the preferred food labelling option, although suggestions to improve it included making it more prominent and larger.
Which? said that people also called for making the scheme easier to understand, such as making the recommended serving size on some products more realistic and consistent.
The consumer champion is now calling on the Government to introduce a mandatory front-of-pack nutrition labelling scheme.
It said this could build on the existing traffic light system to make it work better for shoppers by bolstering consistency, making it more prominent and removing aspects people may find confusing.
Sue Davies, head of food policy at Which?, said: “The UK is in the midst of an obesity crisis and it’s clear that a better approach to front-of-pack labelling is needed to help shoppers make healthier choices.
“Which? is calling on the Government to ensure that all manufacturers and retailers use front of pack nutrition labelling, ideally by making this mandatory.
“Our research shows that people still prefer traffic light nutrition labelling, but that the current scheme needs updating so that it is clearer and simpler and works better for consumers.
“The new system should be backed up with effective enforcement and oversight by the Food Standards Agency and Food Standards Scotland, so shoppers have full trust in the labels on their food.”
In 2022, some 64% of adults in England were estimated to be overweight or living with obesity.
In November it also emerged that one in 10 children in the first year of primary school in England is obese, the highest figure on record outside the pandemic.
It is estimated that obesity costs the NHS more than £11 billion every year.
A Department of Health and Social Care spokesperson said: “This Government is bringing in a modernised food nutrient scoring system to reduce obesity.
“It’s just one element of the strong action we are taking to tackle the obesity crisis as part of our 10 Year Health Plan, which will shift the focus from sickness to prevention.
“We are also restricting advertising of junk food on TV and online, limiting volume price promotions on less healthy foods and introducing mandatory reporting on sales of healthy food.”
Andrea Martinez-Inchausti, assistant director of food at the British Retail Consortium, said: “Retailers have led the way in nutrition labelling, consistently providing advice on healthy living.
“Whether that be through the traffic light system, or other measures, the industry is fully committed to helping improve the health of their customers and are constantly looking for what will work best for them.”
