Are ultra-processed foods a public health hazard?

Ultra-processed foods and public health — I'll gather the latest evidence on risks and what makes them a hazard.

Yes, the current scientific consensus increasingly classifies high consumption of ultra-processed foods (UPFs) as a major public health hazard, though with important nuances.

1. What are ultra-processed foods?

Under the NOVA Food Classification System, developed in Brazil:

> *Ultra-Processed* *Foods* (UPF; NOVA "Group 4") refers to "industrial formulations made entirely or mostly from substances extracted from foods (oils, fats, sugar, starch, and proteins), derived from food constituents (hydrogenated fats and modified starch), or synthesized in laboratories from ..."

It is also defined as "formulations of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes."

Examples include packaged snacks, carbonated soft drinks, instant noodles and ready-made meals, sugary sodas, salty snacks, prepackaged meals.

UPFs are characterized as industrial formulations primarily composed of chemically modified substances extracted from foods, along with additives to enhance taste, texture, appearance, and durability, with minimal to no inclusion of whole foods.

2. How prevalent are they?

This shift has been attributed to behavioural mechanisms, food environments, and commercial influences on food choices.

3. Evidence linking UPFs to adverse health outcomes

Large, consistent epidemiological evidence

Epidemiological evidence is now very consistent. Large prospective studies conducted around the world have linked higher consumption of ultra-processed foods with increased risk of cardiovascular disease, hypertension, stroke, heart failure and diabetes.

A 2024 umbrella review in The BMJ - which evaluated 45 unique pooled analyses including 9,888,373 participants - found:

> Overall, direct associations were found between exposure to ultra-processed foods and 32 (71%) health parameters spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes

And in more detail:

> Overall, direct associations were found between exposure to ultra-processed foods and 32 (71%) health parameters spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes. Based on the pre-specified evidence classification criteria, 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, 95% confidence interval 1.37 to 1.63) and type 2 diabetes (dose-response risk ratio 1.12), as well as higher risks of prevalent anxiety outcomes (odds ratio 1.48) and combined common mental disorder outcomes (odds ratio 1.53)

Highly suggestive (class II) evidence indicated greater exposure was directly associated with higher risks of incident all cause mortality (risk ratio 1.21), heart disease related mortality (hazard ratio 1.66), type 2 diabetes and depressive outcomes.

Other meta-analyses pooling 51 prospective cohort studies found:

> Eating a lot of ultra processed foods was associated with higher risks of cardiovascular events (24%), cancer (12%), obesity/overweight (23%), metabolic syndrome/diabetes (24%), depression/anxiety (27%), digestive diseases (31%), high blood pressure (11%) and death from any cause (18%)

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 showed that higher ultra-processed food intake was associated with around a 50% increased risk of cardiovascular disease-related death, a 48-53% higher risk of anxiety and common mental disorders, and a 12% greater risk of type 2 diabetes.

A randomized controlled trial by Hall et al. also showed people who consume a diet high in ultra-processed foods tend to overeat and gain unwanted weight, with extra calories eaten per day on ultra-processed diet.

2025 Lancet Series: Global threat declaration

In November 2025, a series of three papers published in The Lancet, bringing together 43 international experts, concluded that the global rise of UPFs is a central driver of the worldwide increase in obesity, diabetes, cardiovascular disease, and other chronic conditions. Drawing on more than 100 long-term studies, the analysis found consistent links between UPF consumption and at least 12 health conditions.

The authors reviewed years' worth of evidence, more than a hundred studies which have linked ultraprocessed foods to poor health outcomes, including an increased risk of Type 2 diabetes, obesity, chronic kidney and heart disease, even depression.

According to the Lancet:

> "The rise of ultra-processed foods (UPFs) in human diets is damaging public health, fuelling chronic diseases worldwide, and deepening health inequalities."

Lead author Barry Popkin of the University of North Carolina stated:

> "We can say now that truly ultraprocessed food represents a clear global threat to our health - not only our physical health but also mental health in terms of its impacts on depression."

The Lancet series concluded that ultra-processed foods harm every major organ system in the human body.

4. Proposed mechanisms - why beyond poor nutrition?

Researchers suggest risks are not explained by nutrient content alone:

> Proposed mechanisms include poor nutrient density, glycaemic instability, inflammation, gut–brain axis disruption, and the reward-related effects of highly palatable combinations of refined carbohydrates, fats, salt, and additives

Other characteristics include:

> alterations to food matrices and textures, potential contaminants from packaging material and processing, and the presence of food additives and other industrial ingredients, as well as nutrient poor profiles (for example, higher energy, salt, sugar, and saturated fat, with lower levels of dietary fibre, micronutrients, and vitamins)

Emerging evidence suggests that such properties may pose synergistic or compounded consequences for chronic inflammatory diseases and may act through known or plausible physiological mechanisms including changes to the gut microbiome and increased inflammation.

> The high consumption of ultra-processed foods (UPFs) containing refined ingredients, additives, emulsifiers, and artificial flavouring agents lead to an increased intestinal permeability and dysbiosis

UPFs are also described as aggressively marketed and engineered to be hyper-palatable, driving repeated consumption and often displacing traditional, nutrient-rich foods, with estimates suggesting ultra-processed food addiction affects approximately 14% of adults and 12% of children.

5. Limitations and controversy

Not all scientists agree that the NOVA classification should be the target for policy:

> "Some critics argue that grouping foods that might have nutritional value into the UPF category, including fortified breakfast cereals and flavoured [yogurts], together with products such as reconstituted meats or sugary drinks, is unhelpful."

> "puts products like yogurt or tofu in the same category as soda and candy. It's probably not the right approach."

Harvard's Dr. David Ludwig warned:

> "By focusing on a - such an imprecise target as ultraprocessed foods, there's a risk of demonizing perfectly healthy foods, giving a health halo to patently unhealthy foods and opening the door for industry manipulation."

Methodologically, much evidence is observational, and quality ratings are often low:

> Overall, using the GRADE framework, 22 pooled analyses were rated as low quality, with 19 rated as very low quality and four rated as moderate quality

This means confounding cannot be fully excluded - people eating more UPFs also tend to have lower-quality diets, higher BMI, lower physical activity and socioeconomic disadvantages. The BMJ authors note "convincing" associations were still GRADE very low to moderate quality.

The International Food & Beverage Alliance argues policies that are overly broad in targeting ultraprocessed foods would "reduce the availability of safe, affordable, shelf-stable options globally".

6. Are they officially considered a public health hazard?

The BMJ umbrella review concludes:

> Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes. These findings provide a rationale to develop and evaluate the effectiveness of using population based and public health measures to target and reduce dietary exposure to ultra-processed foods for improved human health

Bottom line: While no single food determines health and some NOVA-defined UPFs (like whole-grain bread, unsweetened yogurt) may be nutritionally reasonable, the totality of evidence now supports that high dietary share of ultra-processed foods - especially sugary drinks, processed meats, and hyper-palatable snacks - is a modifiable risk factor for obesity, type 2 diabetes, cardiovascular disease, depression and premature mortality, and is increasingly framed by leading medical journals as a systemic, global public health threat requiring policy action.

If you are concerned about your own diet, experts suggest prioritizing minimally processed foods - fruits, vegetables, legumes, whole grains, lean meats - and checking ingredient lists for length, added sugars, sodium, and unfamiliar additives, while recognizing cost and access barriers remain real. This is general information, not medical advice; talk to a clinician or dietitian for personalized guidance.