Are ultra-processed foods a public health hazard?

Ultra-processed foods under scrutiny as a public health issue — I'll sift the latest evidence to see what it shows.

Yes - the weight of current epidemiological evidence suggests high consumption of ultra-processed foods (UPFs) is a public health hazard, although scientists debate how to define and regulate them.

1. What are ultra-processed foods?

There is currently no consensus on the definition, but most studies use the NOVA classification developed by Brazilian researchers, which is the most widely used framework.

NOVA classifies foods and drinks based on processing into four groups:

•unprocessed or minimally processed, processed culinary ingredients, processed foods, and ultra-processed foods

•Ultra-processed food is the 4th group that includes products of entirely industrial formulations or made from substances extracted from foods, with minimal whole foods

In the Nova system, ultra-processed foods are characterised by use of certain processing methods and addition of 'cosmetic' additives and substances, such as protein isolates or hydrogenated oils, that are seldom used in meals prepared at home. The NOVA food classification system categorizes foods into four groups based on processing levels, with ultra-processed foods being the most concerning due to their assembly with additives and ingredients uncommon in home kitchens.

Typical examples are ready-to-eat products such as deli meat, microwaveable dinners, or chips, dehydrated soups, potato chips, packaged baked goods, and microwaveable dinners. The foods are loaded with unhealthy fats, salt, sugar, preservatives, and artificial ingredients. Their ultra-processing makes them highly profitable, intensely appealing and intrinsically unhealthy

In general, this system is based on the presence of additives and substances without distinction, making its application subjective.

2. How widespread is exposure?

UPFs now dominate diets in high-income countries:

•In the United Kingdom, ultra-processed foods now account for more than 50% of citizens' mean daily energy intake. The report highlighted that 56 per cent of calories consumed in the UK come from UPFs. Other estimates indicate 57% of the average adult's calorie consumption is from Ultra Processed Foods, as high as 65% for the average child.

•In the United States, between August 2021-August 2023 the mean percentage of total calories from UPFs among those aged one year and older was 55%. For youth the percentage was 61.9% and for adults 53%. The mean percentage during that period for everyone age 1 and older was 55%, among those between ages 1 and 18 the mean was 61.9%.

Given the endemic presence where they contribute to 57% of total calories intake, analyses suggest that actions to reduce consumption could produce important public health benefits.

3. Evidence linking UPFs to adverse health outcomes

Largest umbrella review

The largest summary is a 2024 BMJ umbrella review. It pooled 45 meta-analyses covering almost 10 million people and found that higher UPF exposure was linked to 32 of the 45 (71%) health outcomes assessed, spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal and metabolic health.

The findings, published Feb. 28, 2024 by The BMJ, come from a review of 45 analyses published in the last three years, involving about 10 million people in total.
That is the number of health problems noted in the largest-ever review.

Overall, direct associations were found between exposure to ultra-processed foods and 32 health parameters spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes.

Consistent evidence shows that higher exposure is associated with an increased risk of 32 damaging health outcomes including cancer, major heart and lung conditions, mental health disorders, and early death.

More specifically:

•By systematically analysing evidence from all relevant meta-analyses, we found consistent evidence of higher risk of adverse health outcomes associated with greater ultra-processed food exposure, with convincing and highly suggestive evidence (Classes I and II) relating to adverse cardiometabolic and mental health, and early death

•When scientists graded the evidence, they found the most convincing or highly suggestive evidence linked diets rich in ultra-processed foods with increased risks for premature death, cardiovascular disease, mental health disorders, diabetes, obesity, and sleep problems.

•Convincing evidence (class I) supported direct associations between greater ultra-processed food exposure and higher risks of incident cardiovascular disease related mortality (risk ratio 1.50)

•Highly suggestive (class II) evidence indicated greater exposure was directly associated with disease related mortality (hazard ratio 1.66), type 2 diabetes (odds ratio 1.40), and depressive outcomes (hazard ratio 1.22)

Overall, direct associations were found between exposure to ultra-processed foods and 32 (71%) health parameters.

Other large studies

•People who eat higher amounts of ultra-processed foods - which tend to be high in sodium, sugar, and unhealthy fats - face higher risks of a host of health problems, according to an analysis published May 7, 2025 in Nutrition and Metabolism assessing 6,517 Canadian adults

•A massive Harvard study of more than 200,000 adults over 30 years, combined with 19 other studies for 1.25 million people, found a link between eating ultra-processed foods and greater risk for strokes and heart attacks, as well as cardiovascular disease in general. Those who ate the most had a 17% higher chance of developing cardiovascular disease compared with those who ate the least. When researchers divided foods into categories, the riskiest for heart health were sugary drinks and processed meats.

•A global review published in The Lancet examined 104 long-term studies and found correlation between high consumption and increased risk of 12 health conditions, including type 2 diabetes, cardiovascular disease, kidney disease, depression, and premature mortality.

•The French Agency ANSES, after a systematic review, concluded albeit with a low weight of evidence, that higher consumption of foods classified as ultra-processed under NOVA is associated with higher risk of mortality and chronic diseases such as type 2 diabetes, overweight, obesity, cardioneurovascular diseases, and breast and colorectal cancer.

4. Why might UPFs be harmful? Proposed mechanisms

1.Nutrient profile: Tend to be high in sodium, sugar and unhealthy fats, and loaded with unhealthy fats, salt, sugar, preservatives and artificial ingredients

2.Overconsumption: Formulation often designed to be convenient and appetising, and circumstances of consumption (fast-food, in front of screen) promote excessive food intake

3.Industrial processing effects: Methods used to process foods can lead to formation of new substances, some potentially harmful

The authors of the BMJ umbrella review concluded findings may provide support for targeting minimising ultra-processed food exposure using public health measures, and that findings underscore need for urgent research to understand how ultra-processed foods affect health and measures to target and reduce exposure.

Brazil, Uruguay, Ecuador and Peru have already included the avoidance of ultra-processed foods in their food-based dietary guidelines.

5. Nuance and limitations

Scientists caution against treating all UPFs as equally hazardous:

•The American Heart Association suggests that not all ultra-processed foods are bad. In August 2025, the AHA acknowledged that "not all UPFs are junk foods or have poor nutritional quality; some UPFs have better nutritional value and can be part of an overall healthy dietary pattern".

•This paper underscores that not all ultra-processed foods are created equal, and grouping them together as universally detrimental is overly simplistic.

•Nutritional quality matters far more for health than how processed it is. For example, fortified whole-grain bread, unsweetened yogurt, or plant-based meat alternatives may be classified as UPF but have better nutrient profiles than some minimally processed foods high in sugar or salt.

•Critics contend Nova classification is too broad, and not all ultra-processed food (for example packaged bread and breakfast cereals) is unhealthy.

•ANSES noted current classifications cannot be translated into health risks and cannot be used for purposes of nutritional education, and concluded with low weight of evidence, because most data are observational - based on food frequency questionnaires and dietary recall - which show association not proven causation and are subject to confounding by overall diet quality, lifestyle and socioeconomic status.

6. Bottom line for public health

•High intakes of UPFs - especially sugary drinks, processed meats, salty snacks, sweets and ready meals - are consistently associated with 32 adverse outcomes including cardiovascular mortality, type 2 diabetes, depression, obesity and premature death in large pooled analyses of nearly 10 million people.

•The strength of evidence is strongest for cardiometabolic and mental health outcomes and mortality; associations with asthma, some cancers and gastrointestinal disease are less certain and need further investigation.

•From a population perspective, because more than half of daily calories in the US and UK come from UPFs, even modest risk increases translate to substantial burden of disease.

Public health agencies and researchers increasingly describe excessive UPF consumption as a modifiable risk factor similar to tobacco or excess sugar/salt, and call for policies to reduce exposure - such as front-of-pack warning labels, marketing restrictions, taxes on sugary drinks, reformulation, and promotion of minimally processed whole foods - while emphasizing that dietary guidance should focus on overall nutritional quality rather than processing per se.

Citations (3)

1anses.frNot yet classified
Better understanding the potential health effects of ultra-processed foods | Anses - Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail
Backs: “Yes - the weight of current epidemiological evidence suggests high consumption of ultra-processed foods (UPFs) is a public health hazard, although scientists debate how to define and regulate them.”
2harvard.eduAcademic
More evidence that ultra-processed foods harm health - Harvard Health
Backs: “The NOVA food classification system categorizes foods into four groups based on processing levels, with ultra-processed foods being the most concerning due to their assembly with additives and ingredients uncommon in home kitchens.”
3harvard.eduAcademic
Harvard study pegs the worst ultra-processed foods for your heart - Harvard Health
Backs: “Typical examples are ready-to-eat products such as deli meat, microwaveable dinners, or chips, dehydrated soups, potato chips, packaged baked goods, and microwaveable dinners.”