Ultra-processed foods are linked with 32 harmful health outcomes in a 2024 review covering almost 10 million people, and in a tightly controlled trial they made people eat about 500 extra calories a day. But the evidence also shows they are not all equal: sugary drinks and processed meats look worst, while wholegrain bread, breakfast cereals and yogurt show no harm and sometimes lower risk.
So the smart move is not to fear every packet. It is to cut the worst offenders first and build meals around food that still looks like food.
Key takeaways
- Ultra-processed foods (NOVA group 4) are industrial formulations made mostly from extracted substances and additives such as flavours, emulsifiers and sweeteners.
- In a 2019 NIH trial, people ate about 500 kcal a day more on an ultra-processed diet and gained about 0.9 kg in two weeks.
- A 2024 BMJ umbrella review found convincing evidence linking high intake with about 50% higher risk of cardiovascular death and 12% higher risk of type 2 diabetes. Most of this evidence is observational.
- Sugary and artificially sweetened drinks and processed meats are consistently linked with harm. Wholegrain bread, cereals and yogurt are not.
- Swap the worst categories first; you don’t need to make everything from scratch.
What are ultra-processed foods?
The term comes from NOVA, a system developed by Brazilian researchers that sorts foods by the extent and purpose of processing, not by nutrients. It has four groups:
- Unprocessed or minimally processed foods: fruit, vegetables, eggs, milk, plain meat and fish, dried beans, oats, nuts, frozen vegetables.
- Processed culinary ingredients: oils, butter, sugar and salt, used in home cooking.
- Processed foods: group 1 foods with group 2 ingredients added, such as cheese, simple bread, canned beans and pickles.
- Ultra-processed foods: industrial formulations made mostly from substances extracted from foods (such as hydrolysed proteins, high-fructose corn syrup and hydrogenated oils) plus “cosmetic” additives like flavours, colours, emulsifiers, sweeteners and thickeners.
Typical examples: soft drinks, packaged sweet snacks, most breakfast cereals, mass-produced bread, instant noodles, chicken nuggets, hot dogs and many ready meals. Note that “processed” is not the same as “ultra-processed”: a tin of chickpeas or a block of cheddar sits in group 3.
The 2-minute label test: is it ultra-processed?
The NOVA researchers say the quickest check is the ingredient list. Grab any packet in your kitchen and run through this:
- Count the unfamiliar words. Does it contain at least one ingredient you would never use at home, such as maltodextrin, glucose syrup, hydrolysed protein or “flavourings”?
- Check the end of the list. Emulsifiers, colours, sweeteners and thickeners usually appear last.
- Look for the word “flavour”. Added flavours are a classic marker.
- Ask what job it does. If an additive’s main role is to make the product look, taste or feel better, it counts.
One “yes” puts the product in group 4. Bread made from flour, water, salt and yeast is processed; the same loaf with emulsifiers or preservatives is ultra-processed.
What the evidence says about ultra-processed foods
The trial: Hall 2019
The strongest single study is a 2019 randomised trial at the US National Institutes of Health. Twenty adults lived in a research ward for a month, eating an ultra-processed diet for two weeks and an unprocessed diet for two weeks, in random order.
The meals were matched for calories, sugar, fat, fibre and carbohydrate, and people could eat as much as they liked. On the ultra-processed diet they ate about 500 kcal a day more, ate faster, and gained about 0.9 kg. On the unprocessed diet they lost about the same.
The limits matter: it was small and short, and small differences in protein between the diets could explain up to half the calorie gap. Still, it is the clearest evidence that something about these foods drives overeating.
The big picture: Lane 2024
A 2024 umbrella review in The BMJ pooled 45 meta-analyses with almost 10 million participants. Higher ultra-processed food intake was associated with 32 adverse outcomes.
| Outcome | Higher risk with high intake | Evidence grade |
|---|---|---|
| Cardiovascular disease death | About 50% | Convincing |
| Anxiety and common mental disorders | 48–53% | Convincing |
| Type 2 diabetes | About 12% | Convincing |
| Death from any cause | 21% | Highly suggestive |
| Depression | 22% | Highly suggestive |
These are associations from observational studies. People who eat lots of ultra-processed food also tend to differ in income, smoking, activity and sleep, and studies can’t fully adjust for that. The authors acknowledge they cannot rule out unmeasured confounding.
Not all ultra-processed foods are equal
This is the nuance most headlines skip. When Harvard researchers split ultra-processed foods into subgroups in three large US cohorts, the picture changed.
- Type 2 diabetes (Chen 2023, about 198,000 people): people in the highest fifth of intake had 46% higher risk than those in the lowest. Refined breads, sugar- and artificially sweetened drinks, ready meals, sauces and animal-based products were linked with higher risk. Wholegrain and dark breads, cereals, fruit-based products, yogurt and dairy desserts, and packaged sweet and savoury snacks were linked with lower risk.
- Heart disease (Mendoza 2024, about 207,000 people): the highest intake was linked with 11% higher cardiovascular disease and 16% higher coronary heart disease risk. Sugar- or artificially sweetened drinks and processed meats drove the harm, while bread and cold cereals, yogurt and dairy desserts, and savoury snacks were linked with lower risk.
| Cut these first | Fine in a balanced diet |
|---|---|
| Sugary soft drinks and energy drinks | Wholegrain or seeded bread |
| Diet (artificially sweetened) drinks | Wholegrain breakfast cereals with little sugar |
| Processed meats: bacon, ham, salami, hot dogs | Yogurt (plain is the better pick) |
| Ready meals and takeaway-style frozen dishes | Tinned beans and pulses (processed, not ultra) |
| Refined white bread and pastries | Frozen vegetables and fruit (minimally processed) |
Treat the “lower risk” findings with care. They come from observational data in mostly white US health professionals, and they do not mean crisps are health food. They do mean that a seeded loaf and a pot of yogurt are not the problem.
Ultra-processed food myths vs evidence
| Myth | What the evidence says |
|---|---|
| “All ultra-processed food is junk.” | Wholegrain bread, cereals and yogurt were not linked with harm in large US cohorts, and some were linked with lower risk. |
| “It’s only the sugar, fat and salt.” | In Hall’s trial the diets were matched for sugar, fat, fibre and carbs, yet people still ate about 500 kcal a day more on the ultra-processed one. |
| “Processed and ultra-processed are the same.” | Cheese, tinned beans and simple bread are NOVA group 3, not group 4. |
| “Diet drinks are a free pass.” | Artificially sweetened drinks were linked with higher cardiovascular risk in the 2024 Harvard cohort analysis, though this is observational. |
| “Frozen vegetables are processed junk.” | Plain frozen vegetables and fruit are minimally processed, NOVA group 1. |
Why ultra-processed food is so easy to overeat
Researchers are still working out the mechanism. In Hall’s trial, people ate faster on the ultra-processed diet, which gives fullness signals less time to catch up. Many products are also soft, energy-dense and engineered to taste great, which makes the next handful easy.
For a man over 35 trying to lose fat, this is the practical point. You don’t need willpower against food you never brought home. Our guide to metabolism after 35 explains why what you eat matters more than age for midlife weight gain.
10 practical ultra-processed food swaps
| Instead of | Try |
|---|---|
| Cola or energy drink | Sparkling water with lemon, or unsweetened iced tea |
| Sugary breakfast cereal | Oats with milk, berries and nuts |
| Flavoured fruit yogurt | Plain Greek yogurt with fruit and a little honey |
| Bacon or ham sandwich | Egg, paneer, tuna or hummus sandwich on wholegrain bread |
| Supermarket ready meal | Batch-cooked chilli, dal or curry, frozen in portions |
| Instant noodles | Wholewheat noodles with frozen veg and an egg or tofu |
| Chicken nuggets | Oven-baked chicken strips in egg and wholemeal breadcrumbs |
| Protein bar | Fruit and a handful of nuts, or cottage cheese |
| Crisps every evening | Air-popped popcorn or roasted chickpeas |
| Packaged biscuits and pastries | Toast with peanut butter and banana |
Vegetarian? Pulses, eggs, dairy and tofu all sit in NOVA groups 1 to 3. For more ideas, see our guide to anti-inflammatory eating, which overlaps heavily with a low-UPF diet.
A 4-week plan to cut ultra-processed food
- Week 1, drinks: replace sugary and diet soft drinks with water, sparkling water, tea or coffee.
- Week 2, processed meat: limit bacon, ham, salami and sausages to once a week or less.
- Week 3, breakfast and lunch: switch to oats, eggs, yogurt or wholegrain toast (our vegetarian high-protein breakfasts are all low-UPF), and take leftovers to work twice a week.
- Week 4, evenings: batch-cook two dinners on Sunday, and stop buying the snack you overeat most.
If you have prediabetes or high blood pressure, these steps are among the most useful you can take. See our guides to prediabetes after 35 and heart health after 35.
Safety note: Some ultra-processed products are prescribed for good medical reasons, such as nutrition shakes after surgery or for weight loss under supervision. Don’t stop them without talking to your doctor or dietitian. If cutting foods leaves you anxious about eating or thinking about food constantly, seek support from a professional.
FAQ
Is bread ultra-processed?
It depends on the recipe. Bread made from flour, water, salt and yeast is processed, not ultra-processed. Most mass-produced loaves contain emulsifiers or preservatives, which makes them ultra-processed, yet wholegrain breads were not linked with harm in large US cohorts.
Are protein bars and shakes ultra-processed?
Most are, because they contain protein isolates, sweeteners and flavours. A shake can still be a useful tool if it helps you hit your protein target, and our guide to protein powder: do you need it? explains when it is worth it.
Are frozen vegetables processed?
Plain frozen vegetables and fruit are minimally processed (NOVA group 1). They are a cheap, healthy shortcut. Frozen vegetables in a sauce may be ultra-processed, so check the label.
Are plant-based meat alternatives bad for you?
Most are classed as ultra-processed. Research on them specifically is still limited, so treat them like any other ready-made food: fine occasionally, but beans, lentils, tofu and eggs are better everyday staples.
How much ultra-processed food is too much?
There is no agreed safe limit. In the meta-analysis within the type 2 diabetes study above, each 10% increase in the share of ultra-processed food in the diet was linked with about 12% higher risk, so less is generally better, starting with drinks and processed meats.
Free tool: find lower-calorie, less-processed alternatives to your usual foods with the Healthy Food Swaps tool, then plan a week of real-food meals with the Meal Planner.
Sources
- Monteiro CA et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr, 2019.
- National Institutes of Health. NIH study finds heavily processed foods cause overeating and weight gain (Hall KD et al., Cell Metab, 2019).
- Hall KD et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab, 2019.
- Lane MM et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ, 2024.
- Chen Z et al. Ultra-processed food consumption and risk of type 2 diabetes: three large prospective US cohort studies. Diabetes Care, 2023.
- Mendoza K et al. Ultra-processed foods and cardiovascular disease: analysis of three large US prospective cohorts and a systematic review and meta-analysis. Lancet Reg Health Am, 2024.
This article is for general education and is not medical advice. Check with your doctor before starting a new training or nutrition plan, especially if you have a health condition.
