Ultra-processed foods: what the latest research shows

Ultra-processed foods make up a growing share of most people's diets, and research on them has grown a lot in recent years. Here is what we know today and how to apply it without going to extremes.

What are ultra-processed foods?

They are industrial products made mostly from ingredients you would rarely use in a home kitchen: protein isolates, modified starches, hydrogenated fats, glucose-fructose syrup, flavourings, colourings and emulsifiers. Typical examples are soft drinks, packaged snacks and desserts, sweetened breakfast cereals, most processed meats, ready-made frozen meals and many "fitness" bars.

Not all processing is bad. Frozen vegetables, plain yoghurt, canned beans or wholegrain bread with a short ingredient list are processed, but they don't belong in this group.

The BMJ review: 32 health outcomes

In 2024, The BMJ published an umbrella review summarising 45 meta-analyses from 14 review articles with almost 10 million participants ^[1]. Higher intake of ultra-processed foods was linked to worse results in 32 of 45 health outcomes (71%).

The strongest ("convincing") evidence was for associations with ^[1]:

• a higher risk of death from cardiovascular disease (about 50% higher);
• a higher risk of type 2 diabetes;
• a higher risk of anxiety and common mental disorders.

The evidence was "highly suggestive" for higher all-cause mortality, obesity and depression. For other outcomes, such as asthma, some cancers and blood lipids, the data is still limited ^[1].

Why do we eat more of them? A controlled trial

Observational studies cannot prove cause. That makes a study from the US National Institutes of Health, published in Cell Metabolism, especially valuable ^[2]. Twenty adults lived in a clinic for 4 weeks: two weeks on an ultra-processed diet and two weeks on an unprocessed one. Both diets offered similar amounts of sugar, fat, fibre, salt and protein, and participants could eat as much as they wanted.

On the ultra-processed diet, they ate about 500 kcal more per day on average and gained about 0.9 kg in two weeks. On the unprocessed diet, they lost about the same ^[2]. The study was small and short, but it shows a mechanism: these foods are eaten quickly, easily and in larger amounts.

How certain is this?

The review's authors are clear that most of the included studies are observational and that the way intake was measured varies between them ^[1]. People who eat a lot of ultra-processed food often differ in other habits too. Still, the direction of the results is consistent across many different studies, and the controlled trial shows a plausible mechanism.

How to cut back without going to extremes

• Change your drinks first. Soft drinks and sweetened beverages are the easiest swap with a big effect. Water, sparkling water with lemon, unsweetened tea.
• Read the ingredients, not just the calories. A long list of unfamiliar ingredients is a good sign a product is ultra-processed.
• Have "fast" options ready. Boiled eggs, yoghurt with fruit, nuts, hummus with vegetables instead of packaged snacks.
• Cook in batches. Cooking once for 2 to 3 days reduces the pull of ready meals.
• The 80/20 rule. If about 80% of your food is minimally processed, the rest is rarely a problem.

The personalised meal plan gives you specific, easy recipes that replace ready-made food without making you feel restricted.