Are ultra-processed foods a public health hazard?

Ultra-processed foods are under scrutiny — I'll review the latest evidence on their public-health risks.

Yes — the growing scientific consensus, summarized in major reviews in The BMJ and The Lancet, is that high consumption of ultra-processed foods (UPFs) is a public health hazard, though debate remains about causality and mechanisms.

1. What are ultra-processed foods?

The term comes from the NOVA Food Classification System developed in 2009.

> *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...

The NOVA classification defines ultra-processed foods (UPFs) as "formulations of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes."

The ultra-processed group includes all foods and drinks made using intense physical or chemical processes or containing cosmetic food additives and other industrial ingredients (eg, artificial flavours, hydrogenated oils, glucose/fructose corn syrup). These foods are generally convenient, affordable, highly palatable, and often intensively advertised.

Examples include sugar-sweetened beverages, potato chips and packaged cookies, snacks, drinks, ready meals and many other products created mostly or entirely from substances extracted from foods.

2. Scale of exposure

In countries such as the U.S. and the U.K., ultraprocessed foods make up at least half of the average diet.

More detailed estimates:

There is no official UK threshold for a "safe" level of UPF intake.

This high exposure has put the foods on everyone's radar—including federal policymakers in the U.S., who put out new dietary guidelines this year telling the public to avoid highly processed foods, and the US Department of Health and Human Services noted "research has linked high consumption of ultra-processed foods to preventable chronic diseases, including type 2 diabetes and heart disease".

3. Evidence linking UPFs to adverse health outcomes

Umbrella reviews

The strongest synthesis to date is a BMJ umbrella review:

> The search identified 45 unique pooled analyses, including 13 dose-response associations and 32 non-dose-response associations (n=9 888 373)

> 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

The authors concluded:

> "Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorders and mortality outcomes."

An editorial summarizing the review stated the strongest available evidence pertained to direct associations between greater exposure to ultra-processed foods and higher risks of all cause mortality, cardiovascular disease related mortality, common mental disorder outcomes, overweight and obesity, and type 2 diabetes.

Similarly:

> Reviews published in 2024 and 2025 in The Lancet, BMJ and American Journal of Clinical Nutrition show that: excessive consumption of ultra-processed foods alters the microbiota
> A 2025 Lancet series reviewed more than 100 studies and concluded that ultra-processed foods (UPFs) are now a major driver of chronic disease worldwide

A multicentre prospective cohort analysis in nine European countries published in The Lancet in January 2025, including 428,728 participants, found that ultra processed foods were positively associated with all-cause mortality, as well as mortality from circulatory diseases, cerebrovascular disease, ischemic heart disease, digestive diseases, and Parkinson's disease

Specific risks quantified

4. Why it is considered a hazard — proposed mechanisms

> Scientists say the consumption of ultra-processed foods (UPFs) may promote cardiovascular disease through several mechanisms.

Evidence consistently links high consumption of ultra-processed foods with increased cardiovascular disease risk, supported by epidemiological studies and NF-κB-driven inflammatory mechanisms

> Researchers noted that many links between UPF consumption and cardiometabolic risk factors remained significant even after adjusting for BMI, suggesting that ultra-processed foods may influence health through mechanisms beyond weight gain, such as inflammation, insulin resistance, and poor metabolic regulation

Other proposed mechanisms include:

Commentators have stated:

> "Ultra-processed foods represent a burgeoning health hazard in the standard American diet, potentially contributing to a range of non-communicable diseases including obesity, diabetes, and heart disease"

And in a Cornell national poll:

> "Ultraprocessed foods have entered public consciousness as a major health hazard,"

A BMJ Analysis in 2023 argued:

> Incomplete understanding of the multiple mechanisms underlying the link between ultra-processed foods and cardiometabolic health should not be an excuse for inaction argue Mathilde Touvier and colleagues

Its title was " Ultra-processed foods and cardiometabolic health: public health policies to reduce consumption cannot wait"

5. Limitations and counter-arguments

Not all experts agree the evidence is conclusive for causation. The UK Scientific Advisory Committee on Nutrition (SACN) evaluation was noted by critics who said:

> The main conclusion is that there is no reliable evidence currently available to draw any firm conclusions about the hazards of ultraprocessed foods and the suggestions of adverse effects are based on observational data that is subject to bias and confounding. There are no well-designed randomised controlled trials comparing ultraprocessed foods with an appropriate control.

Limitations frequently cited:

However, the BMJ umbrella review authors and the American Heart Association 2025 science advisory noted growing evidence linking diets high in many ultraprocessed foods with poorer diet quality and increased risk of heart disease, stroke and other cardiometabolic conditions, and concluded that even after adjusting for known risk factors, associations remained.

6. Public health interpretation

Major public health bodies are now treating high UPF consumption as a modifiable risk factor similar to tobacco or excess sugar:

> "The convergence of public belief, bipartisan support and scientific evidence creates a critical window for policy action"

> "These findings add to growing evidence of an association between ultra-processed food and adverse health outcomes that has important implications for dietary advice and food policies," said the BMJ. "The dietary advice is relatively straightforward: eat less ultra-processed food and more unprocessed or minimally processed food."

> UPF consumption is rapidly rising worldwide, comprising over half the average diet in the UK and US - There is a need for public health measures to target and reduce UPF consumption

Bottom line: Based on large observational cohort studies and umbrella reviews covering nearly 10 million people, high intake of ultra-processed foods is directly associated with 32 adverse health outcomes — most convincingly for all-cause and cardiovascular mortality, obesity, type 2 diabetes, depression/anxiety — and is therefore widely described as a burgeoning public health hazard. While definitive proof from long-term randomized trials is lacking and NOVA's classification remains debated, the consistency, dose-response, and plausible biological mechanisms have led The BMJ and Lancet authors to argue that precautionary public health policies to reduce consumption should not wait for perfect mechanistic understanding.