Are ultra-processed foods a public health hazard?

Ultra-processed foods are under major scrutiny — I'll review the evidence on whether they pose a public health hazard.

Yes, the current scientific consensus classifies high consumption of ultra-processed foods (UPFs) as a public health concern / hazard, although experts debate nuances.

What are ultra-processed foods?

The term comes from the NOVA classification system, developed by Brazilian researchers in 2009.

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

More specifically, they are described as:

> industrial formulations of processed food substances (oils, fats, sugars, starch, protein isolates) that contain little or no whole foods and typically include flavorings, colorings, emulsifiers, and other cosmetic additives

Other definition:

>“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 food substrates or other organic sources (flavor enhancers, colors, and several food additives used to make the product hyperpalatable)

Examples include most industrially produced bread and mass-produced baked goods, frozen pizza, instant noodles, flavored yogurt, fruit and milk drinks, diet products, baby food, and most of what is considered junk food, plus packaged snacks, soft drinks, ready meals, and processed meats. The NOVA definition considers ingredients, processing, and how products are marketed; nutritional content is not evaluated.

Nutritionally they:

> tend to be low in dietary fiber and high in calories, salt, added sugar and fat, which are all related to poor health outcomes when eaten excessively

and tend to promote overeating and weight gain, largely due to soft texture, high energy density and hyperpalatable nutrient combinations that alter satiety and food-reward.

Scale of exposure is large: As of 2023, the United States and the United Kingdom lead consumption, with 58% and 57% of daily calories, respectively.

Evidence for health harms

Large-scale reviews

The largest evidence synthesis to date was published Feb. 28, 2024 in The BMJ:

> That's the number of health problems noted in the largest-ever review of studies about the dangers of diets high in ultra-processed foods. The findings, published online 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

> Need more reasons to stop eating ultra-processed food? How about 32 of them? That's the number of health problems noted in the largest-ever review

An analysis of that review found:

> Consistent evidence shows that higher exposure to ultra-processed foods is associated with an increased risk of 32 damaging health outcomes including cancer, major heart and lung conditions, mental health disorders, 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

In more technical terms:

> consistent evidence of a 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

The authors explicitly stated:

> existing evidence as a rationale to target minimising ultra-processed food exposure using public health measures

> A 2024 umbrella review in the BMJ concluded that greater dietary exposure to ultra-processed foods is associated with a higher risk of adverse health outcomes across the lifespan, with the evidence for cardiometabolic and mental health effects rated convincing or highly suggestive

> A subsequent systematic review of 104 prospective studies found that 92 demonstrated an association between an ultra-processed dietary pattern and increased risk of chronic disease in adults

A 2025 analysis found similar risks:

> 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

Specific conditions

Overall epidemiological data suggest consumption is associated with non-communicable diseases and obesity.

Why public health agencies are concerned

There is currently no commonly accepted definition by Codex Alimentarius and food regulators such as the European Food Safety Authority, but agencies are moving to act:

Health organizations worldwide, such as the World Health Organization and the American Heart Association, recommend reducing intake to lower risk of heart disease, advocating for diets rich in fruits, vegetables, whole grains, and lean proteins.

Important nuances and debate

Experts emphasize that the evidence is largely epidemiological, not from randomized controlled trials:

> As of 2026, there have been only few clinical trials which provide limited evidence for an adverse health impact of these foods. Epidemiological data suggest that consumption of ultra-processed foods is associated with non-communicable diseases and obesity

> The effect ... has mainly been investigated using nutritional epidemiology, with no adequate clinical research to establish the health effects of these foods, other than weight gain

And not all UPFs appear equally harmful:

> Research has shown that not all foods classified as ultra-processed are harmful to health. A recent analysis from Harvard researchers found that sugary and artificially sweetened drinks and processed meats increased the risk of heart disease, but that bread, cold cereals, even some savory snacks, had beneficial effects

Similarly:

> A number of studies show that although UPFs in general are associated with higher health risks, there exists a large heterogeneity among UPF subgroups. For example, although bread and cereals are classified as UPFs, a large 2023 study published in The Lancet finds them inversely associated with cancer and cardiometabolic diseases in the European population (hazard ratio 0.97). The study found that animal-based products (HR = 1.09) and artificially and sugar-sweetened beverages (HR = 1.09) are most strongly associated with diseases among UPFs

Critics argue:

> Some authors have criticised the concept of "ultra-processed foods" as poorly defined, and the Nova classification system as too focused on the type rather than the amount of food consumed

Other quotes highlight:

> “While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful,”

> “Whether it’s cooking, freezing, or fortifying with nutrients, the term ‘processed’ itself can be misleading when discussing health

However:

> Most ultraprocessed foods (UPFs) are characterized by poor nutritional quality, contributing to excessive calories, and are typically high in saturated fats, added sugars and sodium (salt)

And even critics agree that some UPF subgroups drive most risk, particularly sugary drinks and processed meats - "the riskiest for heart health were sugary drinks and processed meats (anything salted, cured, smoked, or fermented)".

Bottom line

Major umbrella reviews covering ~10 million people provide convincing/highly suggestive evidence linking high UPF diets to 32 adverse outcomes — including cardiovascular disease, type 2 diabetes, obesity, depression and premature death — leading authors and Harvard Health to advise cutting them out as much as possible and replacing them with less-processed options or whole foods.

Public health bodies therefore increasingly treat excessive UPF consumption as a hazard warranting policy action (dietary guidelines, labeling, taxation, school bans), while researchers call for more nuanced classification and randomized trials to determine which processing factors and which UPF subgroups are truly causal, since some fortified whole-grain breads, cereals, yogurts and plant milks classified as UPF may be nutritious and convenient.