Is ultra-processed food addictive?

In the UK, we eat more ultra-processed food than anywhere else in Europe. 57% of our daily energy intake is from ultra-processed food – and this rises to 66% for adolescents.

Recently, scientists have been sounding the alarm about the dangers of a diet high in UPFs. They claim they’re addictive, bad for your health, and that we should eat less of them. But is this true? And just what are ultra-processed foods?

What is ultra-processed food (UPF)?

UPFs are hard to define but easier to recognise. Doctor and campaigner Chris Van Tulleken provides a useful rule of thumb – if it’s wrapped in plastic and contains an ingredient you wouldn’t find in a domestic kitchen, it’s likely ultra-processed.

The term ‘ultra-processed’ was coined ten years ago by a Brazilian scientist called Carlos Monteiro. He noticed that while many countries had been struggling with worsening obesity and diet-related ill-health for decades, in Brazil, it had gotten worse very suddenly. This coincided with the rapid rise in the availability of heavily processed, pre-packaged foods that are high in salt, fat, and sugar, as well as the decline of cooking from scratch.

To be able to do something about this, Monteiro needed a working definition of these foods. He and his team invented the Nova classification system, which breaks foods down into four broad categories depending on the level of processing they’ve undergone. Ultra-processed foods are Nova level 4 – the highest level of processing. They need factories and big supply chains to make and contain substances like emulsifiers that can’t be bought in a supermarket as an ingredient on their own.

If a food isn’t raw, it’s been processed. Cooking, drying, freezing, pickling, fermenting, and even chopping are all forms of processing. These processing methods are ancient, and humans have eaten foods processed this way for a long time with few ill effects.

Ultra-processing takes this many steps further, using industrial ingredients you wouldn’t find in a kitchen and combining them with additives to make them taste good and prolong their shelf life. The end product has been described as ‘an industrially-produced edible substance’.

While this sounds unpleasant, it doesn’t explain why they’re considered addictive or harmful – but an emerging body of research is unearthing some alarming evidence.

Is ultra-processed food addictive?

Research on ultra-processed food is new, but there’s growing scientific consensus that it is addictive – and 14% of people globally could be addicted to it.

The reasons for this have yet to be fully known, but we do have some ideas.

Ultra-processed food is high in fat, sugar and carbohydrates

From an evolutionary perspective, having a preference for sweet and fatty foods was an advantage in times of food scarcity. In times of food abundance, it’s the opposite.

UPFs are rich in sugars, salt, and fats and extremely easy to digest – most of the nutrients and fibre are stripped out during processing. While the effects within the brain’s reward system are not as pronounced as with drugs or alcohol, ultra-processed foods are cheap, convenient and very easy to access. Cravings, triggers and many of the hallmarks of addiction can happen if a diet high in UPFs is consumed over an extended period.

Ultra-processed food is often pre-digested

Ultra-processed food uses a lot of ingredients that come in powder or slurry form – powdered proteins, starchy flours, processed fats – and lots of sugar, salt and chemical additives. These are then mixed together to create the food in a factory. This means they’ve already been broken down heavily before you eat them and have been likened to the regurgitated food some animals and birds feed their young.

This makes many UPFs easy to digest – too easy. Because much of the fibre is stripped out, UPFs retain the calories but none of the bulk. This bypasses many of the body’s internal mechanisms for detecting when we’re full – meaning it’s easy to overeat compulsively.

Predigestion means rewarding macronutrients, like fat and sugar, hit the gut fast. Like other addictive substances, faster delivery is associated with higher levels of addiction. Cigarettes, which deliver nicotine instantly, are more addictive than patches, and people struggling with opioid addiction are far more likely to snort, smoke or inject opioids than take them orally, which releases the drug more slowly.

What are the health risks of UPFs?

The harms of high ultra-processed food consumption fall into three categories – cardiometabolic, mental health, and mortality.

The BMJ found that ultra-processed food consumption is associated with increased risk for cardiovascular disease, type-II diabetes, obesity and respiratory problems. They are also associated with increases in depression and anxiety. Most concerningly, UPF intake is associated with a 21% increase in all-cause mortality.

The American Journal of Clinical Nutrition also reports that UPF consumption is linked to non-alcoholic fatty liver disease, liver fibrosis and cirrhosis, while Imperial College London links UPF consumption to an increased risk of developing cancer.

Because of these risks, there have been calls to put warning labels on ultra-processed foods similar to cigarettes. Many Latin American countries have started to label UPFs this way. Brazil, where the term ultra-processed was coined, labels foods that are high in fat, sugar and salt.

Steps you can take if you’re worried about your UPF consumption

Try to eat less UPF – but don’t obsess about every single food.

There’s a lot of encouraging evidence that percentage matters when it comes to UPF consumption. A diet high in UPF is associated with negative health outcomes, but you don’t need to purge your entire diet of UPF and read every single label. As the percentage of calories obtained from UPF goes down, health outcomes look better – and this can be achieved from a change in mindset rather than obsessive label-checking.

One study looking at heart health and UPF consumption found that each 10% rise in daily UPF consumption was associated with a 6% rise in heart disease risk. Reversing this, this means reducing your intake by just 10% could decrease your risk of heart disease by 6%.

You can decrease your UPF consumption by focusing on whole and minimally processed foods as much as possible. This means fresh meat, vegetables, legumes, grains and dairy, and cooking from scratch whenever you can. The more you embrace whole foods, which are good for your body and mental health, the more your UPF consumption will naturally decrease.

UPFs and eating disorders

There is very little research on the link between ultra-processed foods and eating disorders. One study did find an association between ultra-processed food consumption, binge-eating disorder and bulimia, but the paper calls for further research.

Many people who are worried about UPF consumption can end up obsessively scrutinising every label for suspicious ingredients. While this is understandable, it’s a difficult task in an environment where so much of our food is ultra-processed. For people who are prone to eating disorders, this also runs the risk of exacerbating orthorexia – a disorder which is categorised as an unhealthy obsession with eating clean foods.

If you’re someone who struggles with disordered eating or is concerned that your relationship with food has become healthy, the best thing you can do is reach out for professional support to get the help you need.