Are ultra-processed foods a public health hazard?

Short answer: Yes, the weight of evidence strongly suggests they are — though some scientific debate remains about why.

The case that UPFs are a public health hazard

Scale of exposure. UPFs now make up a huge share of diets in many countries. More than half of the calories that the average American adult consumes are from ultra-processed foods. The U.S. is among the biggest consumers of UPF in the world, and UPF currently make up more than half of what U.S. adults eat on a daily basis, and two-thirds of what kids and teens eat.

Breadth of associated harms. A 2024 umbrella review of 45 meta-analyses including almost 10 million people found that diets high in UPFs are linked to 32 health conditions, including obesity, type 2 diabetes, cardiometabolic diseases, many cancers, gastrointestinal disorders, asthma, anxiety, depression, cardiovascular events, and all-cause mortality. A major 2024 meta-analysis of prospective cohorts found that high UPF intake was associated with a positive risk of developing diabetes (37%), hypertension (32%), hypertriglyceridemia (47%), low HDL cholesterol (43%), and obesity (32%).

Mortality estimates. A 2025 global analysis found each 10% increase in ultra-processed food intake increases the risk of early death (between ages 30 and 69) by 3%, in a "linear, dose-response relationship", and estimated that potentially 124,000 Americans die prematurely every two years due to ultra-processed food consumption.

New 2025 evidence and mechanisms. A landmark 2025 series in The Lancet, co-authored by over 40 experts, concluded that UPF are a leading contributor to chronic disease. The Lancet's own summary states that the rise of ultra-processed foods in human diets is damaging public health, fuelling chronic diseases worldwide, and deepening health inequalities. Researchers are also beginning to move from correlation toward causal mechanisms: a 2025 randomized controlled trial showed harmful effects of UPFs on weight gain and metabolic and reproductive health, regardless of excessive caloric intake. Food additives are a suspected pathway — an experimental study on mice found two widely consumed emulsifier additives caused transgenerational microbiota alteration that increased long-term susceptibility to metabolic and inflammatory diseases. A large prospective cohort study also revealed positive associations between exposure to two widely consumed food additive mixtures and higher type 2 diabetes mellitus incidence.

A separate 2025 study on younger women found that younger women who eat more UPF, including highly processed bread, breakfast food and soda, may be more likely to develop colorectal cancer, according to research from Harvard's T.H. Chan School of Public Health relying on data from nearly 30,000 nurses.

Equity dimension. Part of the public-health concern is that UPF are frequently more affordable than less-processed foods or fresh produce, and their low cost and wide availability may drive health disparities among populations who already face hunger, undernutrition and higher rates of chronic disease.

The important caveats and scientific debate

Not everyone agrees UPF is a useful or sufficient framework. As one critical review notes, the value of the UPF concept is not universally accepted. Critics point out that the classification system is highly controversial, since in contrast to conventional systems for food classification, the NOVA system disregards the nutritional values of foods.

Crucially, not all UPFs appear equally harmful. A recent critical review found substantial heterogeneity in health outcomes across UPF subtypes, with products like sugar-sweetened beverages consistently associated with adverse outcomes while fortified cereals and certain dairy products demonstrate neutral or protective effects. Similarly, other cohort research found that although artificially and sugar-sweetened beverages, processed meats, and ready-to-eat dishes were associated with higher type 2 diabetes risk, ultraprocessed whole-grain bread, breakfast cereal, and yogurt displayed inverse associations. This suggests the specific ingredients and nutrient profile of a UPF (added sugar, sodium, saturated fat, lack of fiber) may matter as much as the "ultra-processed" label itself.

Bottom line

The consensus among most public health bodies and a growing body of 2024–2025 research — including randomized trials, large cohort studies, and mechanistic animal studies — is that high UPF consumption, as currently practiced in much of the world, is a genuine public health hazard, linked to obesity, diabetes, cardiovascular disease, certain cancers, mental health conditions, and premature death. However, the field is still working out which specific aspects of ultra-processing (additives, texture, energy density, displacement of whole foods, or nutrient profile) drive the harm, and not every UPF carries the same risk — meaning blanket avoidance of anything "ultra-processed" may be a blunter policy tool than targeting the worst offenders (sugary drinks, processed meats, etc.).