Are ultra-processed foods a public health hazard?

Yes — and the scientific consensus on this has grown substantially stronger in 2025–2026

The evidence now points clearly toward ultra-processed foods (UPFs) being a genuine public health hazard, though with some important nuances about which UPFs and how.

The evidence is mounting rapidly

A major Lancet Series published in late 2025 by over 40 leading researchers concluded that a systematic review of 104 long-term studies found that 92 showed higher risks for at least one chronic disease, with meta-analyses identifying significant associations with 12 health conditions including obesity, type 2 diabetes, cardiovascular disease, depression, and premature death. The authors were explicit that although more research on UPFs will continue to be valuable, the current science is already strong enough to justify immediate public health action, and waiting for further studies would allow UPFs to gain an even stronger hold in global diets.

Other umbrella reviews support this: a 2024 analysis of 45 metanalyses, covering nearly 10 million study participants, found "convincing" evidence that a diet high in ultra-processed foods increases the risk of death from cardiovascular disease by 50% and the risk of anxiety by 48%. It also found "highly suggestive" evidence that greater consumption of these foods increases the risk of death from heart disease by 66%, the risk of obesity by 55%, sleep disorders by 41%, Type 2 diabetes by 40%, early death from any cause by 21% and depression by 20%.

There's now causal evidence, not just correlation

Previously, critics argued UPF research was purely observational and couldn't prove causation. That's changing. The American Heart Association's 2025 science advisory noted a dose-response relationship between UPF consumption and cardiovascular events, such as heart attack, transient ischemic attack and stroke, Type 2 diabetes, obesity and all-cause mortality, with high versus low UPF intake linked to a 25%-58% higher risk of cardiometabolic outcomes and a 21%-66% higher risk of mortality.

A landmark randomized controlled trial added important mechanistic support: a 2025 randomized controlled trial has shown the harmful effects of UPFs on weight gain and metabolic and reproductive health, regardless of excessive caloric intake.

Mechanisms go beyond just "junk food" nutrients

Researchers increasingly argue UPFs harm health through pathways separate from simply containing more sugar, salt, and fat. Mechanisms include high energy density, disrupted food matrices, faster eating rates, additives affecting gut, and hyper-palatable formulations. Food packaging itself may contribute: recent studies have confirmed that UPF consumption is associated with increased exposure to endocrine-disrupting chemicals and phthalates used in industrial plastic packaging.

It's not all-or-nothing — nuance matters

Importantly, researchers caution against treating every ultra-processed item identically. The American Heart Association notes that not all UPFs are junk foods or have poor nutritional quality; some UPFs have better nutritional value and can be part of an overall healthy dietary pattern. Examples cited by Johns Hopkins researchers include prepackaged whole grain breads, many yogurts, instant oatmeal, and jarred pasta sauces, which have lower levels of saturated fats and added sugars while still containing a plethora of nutrients that help reduce disease risk.

Scale of exposure is enormous

This isn't a fringe issue — UPFs now dominate diets in many countries. In the U.S., 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. Globally, the proportion of dietary energy from UPFs tripled in Spain (11% to 32%) and China (4% to 10%) over the past three decades, while in the USA and UK, levels have remained above 50% for the past two decades.

Policy response is accelerating

Governments are beginning to act. In the U.S., the FDA and USDA announced a joint Request for Information to help establish a federally recognized uniform definition for ultra-processed foods in 2025. At the state level, California voted to enact the first U.S. law to define and ban unhealthy ultra-processed foods from school meals starting in the 2025–2026 school year.

The bottom line

The weight of evidence—now bolstered by RCTs showing causal mechanisms, not just observational associations—strongly supports classifying high UPF consumption as a genuine public health hazard linked to obesity, diabetes, cardiovascular disease, certain cancers, depression, and premature death. However, the picture isn't uniform: some ultra-processed items (fortified cereals, yogurts, plant-based milks) may be neutral or even beneficial, while others (sugary drinks, processed meats, packaged snacks) carry clear risks. The scientific and policy consensus is shifting toward nuanced, product-specific regulation rather than blanket bans—but the overall message from leading health bodies (Lancet, AHA, WHO) is unambiguous: population-wide reduction in heavily processed, nutrient-poor UPFs is a public health priority.