Why Are UPFs Bad For Us? New Research May Have Answers

Ultra-processed foods, or UPFs, have been linked to everything from gut disruption to “hedonistic hunger”. The Royal College of Physicians has even expressed concern about some UPF ingredients’ possible links to cancer.

But not all experts agree on why they might be detrimental to our health.

Some, like Chris Van Tulleken, author of Ultra-Processed People, seem to argue that the ultra-processing itself causes harm. Others, like psychologist Professor Eric Robinson, said this hasn’t been proven. Then there are those who think issues, when they arise, are probably largely due to UPFs’ nutritional content.

A new review of studies published in the journal Science, which asked whether the adverse effects of UPFs are caused by ultra-processing or nutritional properties, may have an answer.

The Food Safety Authority pointed out that there isn’t a single definition for UPFs.

The Royal College of Physicians describes them as being “characterised by their long list of ingredients that are not typically found in freshly prepared homemade food,” including additives and colourings.

But the definition most experts reach for is set by the NOVA system.

This describes UPFs as foods which contain “formulations of ingredients, mostly of exclusive industrial use, typically created by a series of industrial techniques and processes”.

Researchers looked at five randomised controlled trials that linked UPFs to obesity. These were conducted in different countries, including the USA, UK, Denmark and Japan.

After reviewing those studies, co-author Professor Eric Robinson (you might remember his earlier comments on UPF risks, mentioned above), said: “Collectively, available randomised controlled trials provide weak support for an ultraprocessing-specific effect of UPFs on body weight regulation and cardiometabolic function that is independent of established nutritional determinants”.

In other words, this review didn’t find enough evidence from the trials they looked at to suggest processing itself made UPFs a risk factor for weight gain or heart issues.

It tracks with what the British Nutrition Foundation (BNF) previously said, that UPF studies are “largely based on observational studies that, by design, cannot demonstrate cause and effect”.

There’s a lot more evidence, though, that the typical nutritional profile of many UPFs could be an issue, the Science paper suggested.

The research found that lots of UPFs had four possibly problematic nutritional qualities:

• A soft texture, which might make people eat UPFs faster,
• High calorie density,
• High levels of saturated fat and salt,
• Low fibre and low protein content.

Dr Suzanne Wylie, GP and medical adviser for IQdoctor, previously told HuffPost UK that some UPFs, like tinned beans, can be good for us.

In this study, researchers suggested that nutritional guidelines should focus less on whether foods are technically UPFs and more on whether they’re nutritionally poor, calorie-dense, and easy to eat quickly.

The BNF has previously warned against steering people away from UPFs based on the controversially “broad” NOVA classification system alone.