Are ultra-processed foods a public health hazard?

Growing scientific evidence strongly suggests that ultra-processed foods (UPFs) are indeed a significant public health hazard, though some nuances and debates remain about the exact mechanisms involved.

The Evidence Is Substantial and Growing

The most authoritative recent assessment comes from a major 2025 series in The Lancet, where researchers warned that rising global consumption of ultra-processed foods poses a major threat to health, calling for countries to subject some products made by huge food companies to marketing restrictions and taxes, while also pushing back against criticism that efforts to "manufacture scientific doubt" on the subject were similar to tactics used by the tobacco industry.

The scale of the evidence is notable: 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. One of the Lancet paper's authors, Barry Popkin of UNC, summarized the conclusion bluntly: "We can say now that truly ultraprocessed food represents a clear global threat to our health."

Breadth of Health Conditions Linked to UPFs

A comprehensive umbrella review in The BMJ found that consistent evidence shows 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.

More specific risk estimates from a 2024 review covering nearly 10 million 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%, along with "highly suggestive" evidence that greater consumption 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%.

Other research has extended these findings further:

How UPFs May Cause Harm

Researchers have proposed several biological mechanisms, including dysregulation of blood lipid profiles, alterations in gut microbiota composition, promotion of obesity, induction of systemic inflammation, exacerbation of oxidative stress and impairment of normal metabolic function. A landmark 2025 randomized controlled trial added causal evidence, showing harmful effects of UPFs on weight gain and metabolic and reproductive health, regardless of excessive caloric intake. Scientists also suspect that multiple factors beyond nutritional profile, including food additives, help explain the detrimental effects of UPFs.

Scale of the Problem

This isn't a marginal dietary issue — UPFs dominate modern diets. 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, they 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 recent decades.

There are also equity concerns: 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.

Important Caveats and Ongoing Debate

Despite the weight of evidence, the science isn't entirely settled. There has been intense debate in scientific circles about UPFs, with some health and nutrition experts raising concerns that the term is vaguely defined and that more research is needed. One major critique is that the NOVA classification system used to define "ultra-processed" is quite broad — foods traditionally thought to be healthy, such as fake meat products, plant-based milks and some breads and canned vegetables, could be considered ultra-processed under this system, which complicates blanket conclusions.

Additionally, some data suggests that not all UPFs are equal. One analysis found that when UPFs were divided into subcategories, meat-, poultry-, and seafood-based ready-to-eat foods showed a particularly strong association with mortality outcomes, followed by sugar-sweetened and artificially sweetened beverages, dairy-based desserts and ultra-processed breakfast foods — while other subcategories showed weaker links. In fact, one follow-up study found no consistent association between UPFs and mortality when adjusting for overall diet quality (the Alternative Healthy Eating Index score), suggesting that for some people, overall diet quality might matter more than processing level per se.

Bottom Line

The consensus among leading nutrition and public health researchers — reflected in major journals like The Lancet, BMJ, and Nature, and echoed by bodies like the American College of Cardiology — is that UPFs represent a genuine and serious public health hazard, linked to dozens of chronic diseases and millions of excess deaths worldwide. However, the field is still refining which aspects of UPFs (additives, texture, fiber loss, energy density, or something else) drive harm, and critics caution against treating all "ultra-processed" foods as equally dangerous given the category's breadth. The practical takeaway from most experts is that reducing reliance on heavily processed, nutrient-poor products — particularly sugary drinks, processed meats, and packaged snacks — in favor of whole and minimally processed foods is a well-supported public health priority.