Highlighting ultra-processed food to consumers may be too simplistic as some items may be also classed as ‘green’ under the UK’s traffic light system on food packaging, experts have said.

While some ultra-processed food (UPF) is obviously unhealthy, the team behind the latest research say some UPFs are a ‘grey area’.

While UPFs have been associated with obesity and heart disease, the researchers from University College London highlighted that there is not enough research into the effect of UPFs on general health.

The team carried out a study of almost 3,000 popular food and drink items in the UK and found that:

  • 55% were ultra-processed and were labelled red under the traffic light system, and contained significantly more fat, saturated fat, sugar, salt and energy per 100g than the minimally or unprocessed items, which were more likely to be labelled green;
  • However, some items classed as UPFs were green under the traffic light system, and some minimally processed, such as nuts, seeds and whole milk.

One example was meat-alternative foods which, while being labelled as green, are also classed as a UPF.

UPFs tend to contain more than five ingredients, with the most obvious examples being cakes, biscuits and yoghurts.

Fruit, vegetables and meat are classed as unprocessed while processed foods include tinned food and cheese.

UCL senior research fellow and weight-management specialist Dr Adrian Brown said: “Generally, it [a meat alternative] can be considered highly processed – but if you look at front-of-package labelling for energy, fat, saturated fat and sugar, they’re all green, which would be considered healthy.

“There’s a bit of a grey area [with UPFs] as, at this present time, we only have association data between ultra-processed food and health outcomes such as diabetes and heart disease.”

The UCL team are starting a trial to evaluate how healthy it is to only eat UPFs in comparison to a diet made up of minimally processed food.

This will help to inform whether advice needs to be shared with the public.

Dr Brown said: “We’re putting people on an eight-week diet which meets the government’s recommendations for salt, fat, sugar and energy – what is considered healthy – and we’re comparing the outcomes of them, related to weight and other changes in terms of health as well.”

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