Are ultra-processed foods a public health hazard?

Short answer: Yes, the evidence increasingly points that way — though with important caveats about certainty and mechanism.

The scale of the problem

Ultra-processed foods (UPFs) now dominate many diets. In the U.S., ultra-processed food accounts for nearly 60% of U.S. adults' calorie consumption, and among American children, that portion is close to 70%. More recent CDC data show 53% of calories adults consumed daily came from ultraprocessed foods between 2021 and 2023, and for children 18 and younger, the figure is 61.9%.

What the evidence shows

The most comprehensive recent analysis is a 2024 umbrella review published in The BMJ. It found that researchers carried out an umbrella review of 45 distinct pooled meta-analyses from 14 review articles, published in the past three years and involving almost 10 million participants. The results: consistent evidence shows that 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.

Specific risk increases identified as "convincing" or "highly suggestive" included: 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%, and 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%.

A separate 2024 umbrella review in Clinical Nutrition reached similar conclusions, finding 25 health outcomes associated with UPF consumption, with 2 outcomes—renal function decline and wheezing in children and adolescents—showing convincing evidence, and five outcomes (diabetes, overweight, obesity, depression, and common mental disorders) showing highly suggestive evidence.

A landmark three-part Lancet Series (2025) went further, arguing the displacement of traditional diets by UPFs is a central driver of disease, concluding that the hypothesis that this pattern increases the risk of multiple diet-related chronic diseases is substantiated by more than 100 prospective studies, meta-analyses, randomised controlled trials, and mechanistic studies, covering adverse outcomes across nearly all organ systems.

Why UPFs may cause harm (not just correlate with it)

Researchers point to several plausible mechanisms:

Important caveats and scientific debate

Not all researchers agree the evidence is airtight. A 2023 meta-analysis found a consistently positive association between high UPF intake and increased risk of diabetes, hypertension, hypertriglyceridemia, low HDL, and obesity, even though the quality of evidence was not satisfying, with risks varying by more than 50% depending on methodology used.

Other researchers caution that:

The policy and public response

The concern has moved from academic circles into policy and public opinion. A 2025 national survey found more than 60% of respondents agreed that such foods are addictive and major causes of obesity, Type 2 diabetes and heart disease, perceiving the health risks as less serious than cigarettes but roughly equivalent to alcohol. This has translated into policy momentum: ultraprocessed foods have drawn increasing scrutiny from policymakers across ideological lines, including restrictions on school meals in California and state attorneys general investigating companies.

Bottom line

The weight of evidence — spanning dozens of meta-analyses, large cohort studies, and emerging mechanistic research — supports treating heavy UPF consumption as a genuine public health concern linked to higher risks of obesity, diabetes, cardiovascular disease, certain cancers, and all-cause mortality. However, UPFs are a very heterogeneous category (ranging from sodas to whole-grain breads), much of the evidence remains observational rather than proving direct causation, and effect sizes for individual outcomes are often modest. Most experts agree the safest approach is moderation and prioritizing whole/minimally processed foods, while researchers continue working to identify which specific aspects of "ultra-processing" (additives, texture, energy density) drive the harm.