Are ultra-processed foods a public health hazard?

Ultra-processed foods are now front and center in public health debate — I'll pull the latest evidence on their risks and what it means for health.

Yes - the current consensus among major public health bodies and large evidence reviews is that high consumption of ultra-processed foods (UPFs) is a public health hazard, although debate remains about whether it is "processing" itself or the nutritional profile and food environment that causes harm.

1. What are ultra-processed foods?

The term comes from the NOVA classification system developed by Brazilian epidemiologist Carlos Monteiro.

> 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

The Lancet Diabetes & Endocrinology definition describes them as:

> “formulations of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes.” Often high in sugar, salt, and fat; low in fibre, protein, and micronutrients; and containing additives, emulsifiers, stabilisers, colourants, and artificial sweeteners, UPFs generally having a poor nutrient profile

Examples include packaged baked goods and snacks, fizzy drinks, sugary cereals, and ready-to-eat or heat products, deli meat, microwaveable dinners or chips, which typically have long ingredients lists, with lots of additives such as preservatives, oil, sugar, salt, coloring, and flavoring.

Put simply, they contain ingredients never or rarely used in kitchens.

2. How widespread is exposure?

UPFs can account for up to 58% of total daily energy intake in some high-income countries, and have rapidly increased in many low and middle-income nations.

> In the UK and US, more than half the average diet now consists of UPF. For some, especially people who are younger, poorer or from disadvantaged areas, a diet comprising as much as 80% UPF is typical

They now account for roughly half of adults’ calories in both the UK and US, with US adults at about 55-60% and children at about 70% in recent national data.

The 2025 Lancet Series on ultra-processed foods, 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 finding consistent links between UPF consumption and at least 12 health conditions.

3. What does the epidemiological evidence show?

The largest summary to date is an umbrella review (review of reviews) published Feb. 28, 2024, in The BMJ.

> 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

Researchers carried out an umbrella review of 45 distinct pooled meta-analyses from 14 review articles associating ultra-processed foods with adverse health outcomes, none funded by UPF manufacturers.

> Overall, the results show that higher exposure to ultra-processed foods was consistently associated with an increased risk of 32 adverse health outcomes

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.

Specifically:

> 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

> Highly suggestive evidence also indicated that higher ultra-processed food intake was associated with a 21% greater risk of death from any cause, a 40-66% increased risk of heart disease-related death, obesity, type 2 diabetes, and sleep problems, and a 22% increased risk of depression

Evidence for associations with asthma, gastrointestinal health, some cancers, and cardiometabolic risk factors, such as high blood fats, remains limited and need further investigation.

Other reviews echo this:

A 2025 analysis published in JAMA Oncology found that women who consumed the highest amounts of ultra-processed foods—about 10 servings per day—had a 45% higher risk of developing precancerous colorectal polyps.

4. Why might UPFs be hazardous? Mechanisms proposed

Researchers conclude: “These findings support urgent mechanistic research and public health actions that seek to target and minimize ultra-processed food consumption for improved population health.”

5. Nuance and ongoing debate

Not all scientists agree that "ultra-processing" itself is the hazard.

> “Much of the public and policy debate assumes that UPFs exert unique, processing-specific harms, yet the RCTs often cited in support of this idea were not designed to isolate ‘ultraprocessing’ from well-known nutritional factors,”

> “UPF classifications capture many unhealthy foods, but they also sweep in items that are nutritionally sound or even beneficial,” ... “The randomized trials do not show a consistent adverse effect of UPFs on glucose, insulin, triglycerides, blood pressure, or insulin resistance. The current evidence base simply does not support the idea that ‘ultraprocessing’ itself is a meaningful biological exposure.”

Other critics note:

> “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,”

And that studies are largely observational, so they cannot suggest a causal relationship, and high UPF consumption is also associated with other behaviors and environmental factors that might be driving association, particularly as UPFs tend to be cheap, convenient. Low cost, convenience, palatability, and often, a lot of sugar, sodium, saturated fat, and calories that usually ride along with it may be the true culprits.

Due to the lack of conclusive evidence on mechanisms independent of diet quality, the 2025 Dietary Guidelines Advisory Committee declined to take a stance on ultra-processed foods.

6. Public health interpretation

Major agencies now treat high UPF consumption as a serious public health concern:

An editorial accompanying the BMJ umbrella review argued it is now time for United Nations agencies, with member states, to develop and implement a framework convention on ultra-processed foods similar to the framework on tobacco.

Bottom line: Based on consistent associations across ~10 million people with 32 health outcomes, especially cardiometabolic and mental health outcomes, most public health experts now consider diets high in ultra-processed foods a public health hazard requiring population-level action, even as research continues to disentangle whether risk comes from processing per se versus nutrient profile, additives, and broader food environment.

This summary is for information only and not medical advice. If you are concerned about your diet, consult a healthcare professional or registered dietitian.