Are ultra-processed foods a public health hazard?

Yes — the evidence increasingly supports that ultra-processed foods (UPFs) are a genuine public health hazard, though scientists are still working out exactly why.

What the evidence shows

Strong observational associations with chronic disease. A large body of prospective cohort research consistently links UPF consumption to poor health outcomes. A scoping review for the Nordic Nutrition Recommendations found that greater consumption of UPFs is associated with weight gain and increased risk of obesity, cardiovascular disease, type 2 diabetes, and all-cause mortality, with additional but less certain links to hypertension, cancer, and depression. A meta-analysis of prospective cohorts similarly found a consistently positive association between high UPF intake and increased risk of developing diabetes (37%), hypertension (32%), hypertriglyceridemia (47%), low HDL cholesterol concentration (43%), and obesity (32%).

Mortality risk appears dose-dependent. Tufts University researchers found that for every 10% increase in calories from ultra-processed foods, mortality risk rose by 9%. Practically, someone who gets 60% of their calories from these products... has a 27% greater chance of dying of all causes compared to someone who limits these foods to 30% of their diet. Interestingly, not all UPFs are equal — ultra-processed whole grain breads and cereals were associated with neither positive nor negative impacts on health, and ultra-processed vegetables and legumes were associated with a reduced likelihood of death.

Emerging risks beyond metabolic disease. Newer research has expanded the list of concerns to include kidney disease — a meta-analysis found higher UPF intake was significantly associated with increased CKD risk (pooled log-hazard ratio = 0.17; 95% CI: 0.07–0.28; p < 0.001) — as well as links to cognitive decline, stroke, and even early signs of Parkinson's disease in observational studies.

2025 was a turning point for causal evidence. Until recently, most evidence was correlational. That changed with new experimental work: 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. Mechanistic studies are also emerging — for example, an experimental study on mice found that two widely consumed food additive emulsifiers caused transgenerational microbiota alteration that led to increased long-term susceptibility to metabolic and inflammatory diseases. This matters because the harmful effects of ultra-processed food cannot be entirely attributed to its poor nutritional quality alone — additives, food structure, and texture appear to play independent roles.

Scale of the problem. This isn't a fringe issue — UPF consumption is rising, accounting now for more than half of the daily calories of US, Canadian, or British diets, and consumption is also climbing rapidly in lower-income countries, raising concerns about a widening global burden of chronic disease.

The scientific consensus is strengthening, but with caveats

In late 2025, over 40 leading researchers published a major series in The Lancet concluding that UPF are a leading contributor to chronic disease, and specifically that the widespread sale and consumption of UPF creates large corporate profits while making people sick.

That said, researchers urge some caution: the risk estimates varied significantly depending on the methodology used to assess UPF consumption, with a difference of more than 50% between the methods, and one review noted that further large-scale, high-quality prospective cohort studies, intervention studies and experimental studies are needed... to provide a safe recommended daily intake (RDI) of UPFs in the future. Scientists are also debating whether policy should target all UPFs uniformly or focus on specific harmful subcategories, since — as seen with whole-grain products and vegetables — not every ultra-processed food behaves the same way metabolically.

Bottom line

The weight of evidence — spanning large cohort studies, systematic reviews, and now randomized controlled trials — supports treating high UPF consumption as a significant public health concern linked to obesity, diabetes, cardiovascular disease, kidney disease, and premature death. While the field is still refining which aspects of UPFs (additives, texture, energy density, or the food matrix itself) drive these harms, the overall pattern is consistent enough that major public health bodies and leading journals like The Lancet are now calling for stronger policy responses.