Are ultra-processed foods a public health hazard?

Ultra-processed foods and public health — I'll pull the latest evidence on their risks.

Yes, the current scientific consensus is that high consumption of ultra-processed foods (UPFs) is a public health hazard, although experts emphasize nuance about what counts as a UPF.

1. What are UPFs?

Under the NOVA classification system developed in 2009, UPFs are defined as:
> novel branded products made from inexpensive industrial ingredients such as hydrogenated oils, protein isolates or glucose/fructose syrup, and cosmetic food additives (e.g. dyes, artificial sweeteners, emulsifiers). They are designed and marketed to displace fresh and minimally processed foods

NOVA categorizes foods by type, intensity and purpose of processing, with Group 4 being ultra-processed.

Common examples include packaged snacks, processed meat products, sugary drinks, and some ready-made meals.

2. Scale of exposure - why it is a population problem

Consumption has increased substantially worldwide in recent decades.

National surveys indicate:

> estimated energy contribution of UPFs to total household food purchases or daily food intake tripled in Spain (11% to 32%) and China (4% to 10%) over the last three decades, and increased (10% to 23%) in Mexico and Brazil over the previous four decades. In the USA and UK, it increased slightly over the last two decades, maintaining levels above 50%.

Researchers note UPFs are now more than 70% of what you find in grocery stores in the US and are global annual sales of $1.9 trillion, the most profitable food sector.

Diets high in UPFs are linked to overeating, poor nutritional quality (too much sugar and unhealthy fats, and too little fibre and protein) and higher exposure to harmful chemicals and additives.

3. Evidence linking UPFs to adverse health outcomes

a) The Lancet Series (2025)

An international series published in The Lancet reviewed years of evidence:

> The increase of ultra-processed foods (UPFs) in diets worldwide presents an urgent challenge to health, global experts have warned in a series of articles, published in The Lancet.

> There are three papers, they're published in The Lancet, and they 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.

One author concluded:

> 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 series concluded:

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

A systematic review conducted for the Series, encompassing 104 long-term studies, found 92 reported greater associated risks of one or more chronic diseases, with meta-analyses showing significant associations for 12 health conditions, including obesity, type 2 diabetes, cardiovascular disease, depression, and early death.

b) BMJ Umbrella Review (2024) - largest synthesis

> A 2024 umbrella review in The BMJ associated higher ultra processed food consumption with 32 adverse health outcomes

Specifically:

> Forty-five unique analyses, including 13 dose-response associations and 32 nondose-response associations (n=9,888,373), met the eligibility criteria. Overall, exposure to ultra-processed foods directly correlated with 32 (71 percent) health parameters, including mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes.

Graded evidence showed:

> Based on convincing evidence (class I), higher exposure to ultra-processed foods had direct associations with increased risks of incident CVD-related death (risk ratio [RR], 1.50, 95 percent confidence interval [CI], 1.37‒1.63; GRADE=very low) and T2D (dose-response RR, 1.12, 95 percent CI, 1.11‒1.13; moderate), as well as prevalent anxiety outcomes (odds ratio [OR], 1.48, 95 percent CI, 1.37‒1.59; low) and combined common mental disorder outcomes (OR, 1.53, 95 percent CI, 1.43‒1.63; low).

> Highly suggestive (class II) evidence also showed direct associations between higher exposure to ultra-processed foods and greater risks of incident all-cause death (RR, 1.21, 95 percent CI, 1.15‒1.27; low), heart disease-related death (hazard ratio [HR], 1.66, 95 percent CI, 1.51‒1.84k; low), T2D (OR, 1.40, 95 percent CI, 1.23‒1.59; low), and depressive outcomes (HR, 1.22, 95 percent CI, 1.16‒1.28; low)

This complements earlier summaries that:

> Convincing evidence (p -6) was found for a direct association between higher UPF consumption and: • Allcause mortality (RR 1.21; 95% CI 1.15-1.27)• Cardiovascular disease mortality (RR 1.20; 95% CI 1.12-1.29)• Type 2 diabetes (RR 1.40; 95% CI 1.29-1.52)• Adverse mental health outcomes, including depression (RR 1.22; 95% CI 1.16-1.28)

c) Large meta-analysis of 51 cohorts (2025-2026)

A large analysis covering 8,819,894 adults from 51 prospective cohort studies found:

> A large study has found that eating more ultra-processed foods (UPFs) was linked to a higher risk of disease and early death.

Detailed results:

> Overall, people consuming more ultra-processed food had higher risks of several chronic health conditions and death from any cause. Compared with lower consumption, higher UPF intake was associated with: - 24% higher risk of cardiovascular events - 12% higher risk of cancer - 23% higher risk of obesity or overweight - 24% higher risk of metabolic syndrome or diabetes - 27% higher risk of depression or anxiety - 31% higher risk of digestive diseases - 18% higher risk of death from any cause.

Dose-response:
> The findings suggest that every additional 100 grams of UPFs consumed per day was associated with a 14% higher risk of cardiovascular events, 11% higher risk of high blood pressure, 4% higher cancer risk, 3% higher risk of death from any cause, and 2% higher risk of metabolic syndrome/diabetes.

Consistent with that:

> A meta-analysis of 51 studies (8.8 million adults) links ultra-processed food (UPF) consumption to a 24% higher risk of cardiovascular events, 12% increased cancer risk, 18% greater all-cause mortality

Other research notes Harvard data that people who consumed significant amounts of ultra-processed food were 10% more likely to die — especially from heart disease and diabetes — during two-decade follow-up.

Mechanisms proposed include excess sugar, salt and calories; food additives and cocktail effects of multiple additives; loss of nutrients during processing; contaminants from packaging like microplastics; and effects on gut microbiome promoting inflammation and insulin resistance and .

4. Is it a hazard requiring public health action?

The Lancet authors explicitly call it a hazard justifying policy action:

> Evidence reviewed in the Series shows that diets high in UPFs are linked to overeating, poor nutritional quality ... and are associated with an increased risk of multiple chronic diet-related diseases.

> While healthy debate about UPFs within the scientific community is welcomed ... The growing body of research suggests diets high in ultra-processed foods are harming health globally and justifies the need for policy action.

Proposed measures mirror tobacco control:

> they say it's time to use a playbook similar to what was used against Big Tobacco, so things like taxes on sodas, warning labels on packaged foods, a ban on marketing these foods to kids and removing ultraprocessed foods from big institutions like schools and hospitals.

Authors propose:

> Addressing this challenge requires governments to step up and introduce bold, coordinated policy action - from including markers of UPFs in front-of-package labels to restricting marketing and implementing taxes on these products

and

> We need a strong global public health response - like the coordinated efforts to challenge the tobacco industry.

They argue corporations, not individual choices, are driving the rise through cheap ingredients, aggressive marketing, and political lobbying to block regulation and .

5. Important nuances and limitations

Experts caution against calling every UPF inherently unhealthy:

> Ultra-processed foods (UPFs) have developed an unhealthy reputation, but not all UPFs are created equally. A new scientific advisory from the American Heart Association (AHA) has challenged the idea that all ultra-processed foods are unhealthy.

> UPF classifications capture many unhealthy foods, but they also sweep in items that are nutritionally sound or even beneficial

As noted in coverage of the guidelines:

> lots of food is considered ultraprocessed, and not all of it is unhealthy. So some yogurts, packaged whole wheat bread and jarred pasta sauces are in the same ultraprocessed category as a big bag of potato chips.

> By focusing on a - such an imprecise target as ultraprocessed foods, there's a risk of demonizing perfectly healthy foods

Methodologically, most evidence is observational:

> However, the analysis relied in part on self-reported dietary information and could not fully account for broader lifestyle factors, so the findings do not establish cause and effect.

The series authors themselves acknowledge:

> valid scientific critiques of Nova and UPFs - such as lack of long-term clinical and community trials, an emerging understanding of mechanisms, and the existence of subgroups with different nutritional values

Conclusion

Current evidence — umbrella review of almost 10 million people finding 32 linked adverse outcomes, a 51-study meta-analysis of 8.8 million people showing dose-dependent increases in cardiovascular, metabolic, cancer, mental health and mortality risk, and the 2025 Lancet Series synthesizing over 100 studies — provides convincing to highly suggestive evidence that diets high in UPFs increase risk of cardiovascular death, type 2 diabetes, obesity, depression/anxiety, and all-cause mortality.

Because UPFs are displacing healthier foods, are cheap, heavily marketed, and now contribute >50% of energy intake in the US/UK, leading researchers and journals describe them as a major global public health threat that warrants population-level policies (front-of-pack labels including UPF markers, taxes, marketing restrictions, limits in schools/hospitals) alongside making minimally processed foods more affordable — similar to tobacco control — while recognizing that not every individual UPF product is equally harmful and that further mechanistic and trial research is needed.