Are ultra-processed foods a public health hazard?

YesSays it is contested

Yes, diets high in ultra-processed foods (UPFs) are widely regarded by researchers, public health experts, and organizations as a significant public health hazard, contributing substantially to the global burden of diet-related chronic diseases. This view is supported by extensive observational evidence, meta-analyses, mechanistic studies, and some randomized controlled trials (RCTs), though nuances exist regarding classification, causality, and heterogeneity within the category.[1]

What Are Ultra-Processed Foods?

UPFs are defined primarily by the NOVA classification system (developed in Brazil). They are industrial formulations made mostly from substances extracted from foods (e.g., oils, sugars, starches, proteins) or synthesized, with little to no intact whole foods. They typically contain additives for flavor, texture, color, or shelf life (e.g., emulsifiers, artificial sweeteners, colors) not commonly used in home cooking. Examples include soft drinks, packaged snacks, instant noodles, ready-to-eat meals, many breakfast cereals, processed meats, candies, and some yogurts or breads.[2]

In high-income countries like the US, UPFs often supply over 50% of adults’ calories (and higher for children), displacing traditional diets based on fresh or minimally processed foods. Consumption is rising globally.[3]

Key Evidence of Health Risks

Large umbrella reviews and meta-analyses of prospective cohort studies consistently link higher UPF intake to elevated risks across many outcomes:

•A 2024 BMJ umbrella review of meta-analyses (covering nearly 10 million people) found direct associations with 32 (71%) health parameters, spanning mortality, cardiometabolic disease, cancer, mental health, respiratory, gastrointestinal, and other outcomes. “Convincing” evidence (Class I) supported links to higher cardiovascular disease (CVD)-related mortality (risk ratio ~1.50) and type 2 diabetes (dose-response), plus anxiety and common mental disorders. “Highly suggestive” evidence covered all-cause mortality (~1.21), heart disease mortality, obesity, depression, and others. GRADE quality was mostly low or very low (typical for observational nutrition data), with some moderate.[2]

•A major 2025 Lancet series synthesized narrative/systematic reviews, meta-analyses of >100 prospective studies, RCTs, and mechanistic work. It concluded that UPF-dominated patterns deteriorate diet quality (nutrient imbalances, excess energy intake from hyper-palatability/energy density/soft textures/disrupted matrices, fewer protective phytochemicals, more additives/toxins/endocrine disruptors) and drive multiple chronic diseases via various pathways. Risk estimates for high vs. low UPF intake were comparable in magnitude (but opposite direction) to the protective effects of Mediterranean diets. The series calls this a key driver of the escalating global chronic disease burden and urges policy action.[1]

•Other reviews and studies link higher intake to overweight/obesity, hypertension, dyslipidemia, CVD events, certain cancers (e.g., colorectal precursors), chronic kidney disease, Crohn’s, depression/anxiety, cognitive issues, and all-cause mortality, often with dose-response patterns (risk rises with greater intake).[4]

The American Heart Association (AHA) has issued science advisories noting that excess UPFs (especially those high in saturated fat, added sugars, and sodium—HFSS) are tied to higher cardiometabolic risk, with risks rising notably above ~10-15% of energy intake. They recommend minimizing most UPFs.[5]

Experimental support: A landmark inpatient RCT by Kevin Hall et al. (2019) matched UPF and unprocessed diets for presented calories, macronutrients, sugar, sodium, and fiber. Participants freely ate ~500 extra kcal/day on the UPF diet, gaining weight (~0.9 kg in 2 weeks) while losing weight on the unprocessed diet. Follow-up work points to energy density and hyper-palatability as key drivers of overconsumption; processing can also alter metabolic (e.g., insulin) and brain reward responses even with matched nutrients.[6]

Plausible mechanisms include:

•Poor nutrient profiles and displacement of healthier foods.

•Hyper-palatability, high energy density, and easy-to-eat textures promoting overeating.

•Disrupted food matrices affecting digestion/satiety.

•Additives, processing contaminants (e.g., acrylamide, packaging chemicals like bisphenols), and mixtures with potential “cocktail” effects.

•Impacts on the gut microbiome, inflammation, insulin resistance, and other pathways.[1]

Nuances, Criticisms, and Limitations

•Not all UPFs are equal: Sodas and processed meats rank among the worst. Some (e.g., certain whole-grain breads, low-sugar yogurts, or nut spreads) have better profiles and may fit into healthy patterns in moderation. The AHA notes a small subset may be acceptable. Focusing solely on “ultra-processed” without nutrient quality can oversimplify.[3]

•NOVA critiques: The category is broad/heterogeneous; classification can be subjective or rely on proxies (ingredients/additives); it may not fully isolate “processing” from nutrient quality or other factors. Some argue associations largely reflect poor overall diet (high HFSS). Critics note potential misclassification and that processing itself has benefits (safety, convenience, fortification, shelf life). A notable portion of critical papers have food industry ties. Defenders argue NOVA has strong predictive utility for health outcomes and policy, analogous to other useful (if imperfect) public health constructs.[7]

•Evidence limitations: Mostly observational (residual confounding possible, e.g., lifestyle factors); GRADE often low due to this. Long-term RCTs on hard endpoints are lacking/impractical. Causality is strongly suggested by consistency, dose-response, experiments, and mechanisms but not fully proven for every outcome.

•WHO and others are developing guidelines, profiling tools, and definitions to support action, building on existing advice to limit free sugars, sodium, unhealthy fats, etc. Some countries already recommend limiting UPFs in dietary guidelines.[8]02326-8/fulltext)

Public Health Perspective

High UPF intake is seen as a systemic issue driven by commercial food systems, convenience, marketing, affordability, and time scarcity—exacerbating obesity, diabetes, heart disease, and related multimorbidity epidemics. Experts describe it as “the health challenge of our time.” Recommended responses include promoting whole/minimally processed foods (vegetables, fruits, legumes, whole grains, nuts, seeds, seafood, lean proteins); multipronged policies (front-of-pack labels, taxes/subsidies targeting HFSS products, marketing restrictions especially to children, procurement standards); industry reformulation; and more research on mechanisms and subtypes.[9]

Bottom line: While individual UPFs vary and absolute causation has caveats, the overwhelming body of evidence indicates that dietary patterns dominated by ultra-processed foods harm population health and warrant treating them as a public health priority for reduction—favoring fresh and minimally processed alternatives wherever feasible. Individual advice should emphasize overall diet quality, not perfectionism around every packaged item.

8.https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)02326-8/fulltext — https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)02326-8/fulltext

Citations (9)

1sciencedirect.comAcademic
https://www.sciencedirect.com/science/article/pii/S014067362501565X
Backs: “This view is supported by extensive observational evidence, meta-analyses, mechanistic studies, and some randomized controlled trials (RCTs), though nuances exist regarding classification, causality, and heterogeneity within the category.”
evidence, article, points to yes. Claim: Lancet 2025 series concluded UPF-dominated diets harm diet quality, drive chronic disease, and call for policy action.
2bmj.comAcademic
https://www.bmj.com/content/384/bmj-2023-077310.abstract
Backs: “Examples include soft drinks, packaged snacks, instant noodles, ready-to-eat meals, many breakfast cereals, processed meats, candies, and some yogurts or breads.”
statistic, article, points to yes. Claim: BMJ 2024 umbrella review found direct associations with 32 health parameters, including CVD mortality RR ~1.50 and all-cause mortality ~1.21.
3uclahealth.orgAcademic
https://www.uclahealth.org/news/article/are-all-ultra-processed-foods-bad-you
Backs: “In high-income countries like the US, UPFs often supply over 50% of adults’ calories (and higher for children), displacing traditional diets based on fresh or minimally processed foods. Consumption is rising globally.”
evidence, article, neutral. Claim: UPFs supply over 50% of US adult calories; not all UPFs are equally unhealthy.
4news-medical.netNews and mediaquality 0.52
https://www.news-medical.net/news/20260922/Higher-ultra-processed-food-intake-linked-to-multiple-health-risks.aspx
Backs: “Other reviews and studies link higher intake to overweight/obesity, hypertension, dyslipidemia, CVD events, certain cancers (e.g., colorectal precursors), chronic kidney disease, Crohn’s, depression/anxiety, cognitive issues, and all-cause mortality, often with dose-response patterns (risk rises with greater intake).”
evidence, article, points to yes. Claim: Higher intake linked to obesity, hypertension, CVD, cancers, kidney disease, depression, and all-cause mortality with dose-response patterns.
5patientcareonline.comNews and media
https://www.patientcareonline.com/view/excess-intake-of-ultraprocessed-foods-tied-to-higher-cardiometabolic-risk-aha-advisory-says
Backs: “The American Heart Association (AHA) has issued science advisories noting that excess UPFs (especially those high in saturated fat, added sugars, and sodium—HFSS) are tied to higher cardiometabolic risk, with risks rising notably above ~10-15% of energy intake. They recommend minimizing most UPFs.”
attribution, article, points to yes. Claim: AHA advisory ties excess UPFs to higher cardiometabolic risk and recommends minimizing most of them.
6researchgate.netAcademic
https://www.researchgate.net/publication/333151637_Ultra-Processed_Diets_Cause_Excess_Calorie_Intake_and_Weight_Gain_An_Inpatient_Randomized_Controlled_Trial_of_Ad_Libitum_Food_Intake
Backs: “Follow-up work points to energy density and hyper-palatability as key drivers of overconsumption; processing can also alter metabolic (e.g., insulin) and brain reward responses even with matched nutrients.”
evidence, article, points to yes. Claim: Hall 2019 inpatient RCT showed ~500 extra kcal/day and weight gain on the UPF diet.
7nature.comAcademic
https://www.nature.com/articles/s43016-026-01371-8
Backs: “Defenders argue NOVA has strong predictive utility for health outcomes and policy, analogous to other useful (if imperfect) public health constructs.”
evidence, article, neutral. Claim: NOVA is criticized as broad and heterogeneous, with some critical papers industry-tied, while defenders cite its predictive utility.
8thelancet.comAcademic
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)02326-8/fulltext
Backs: “Some countries already recommend limiting UPFs in dietary guidelines.”
background, article, neutral. Claim: WHO and others are developing guidelines and definitions; some countries already recommend limiting UPFs.
9aamc.orgNonprofits and think tanks
https://www.aamc.org/news/health-challenge-our-time-what-academic-experts-want-you-know-about-ultra-processed-foods
Backs: “Experts describe it as “the health challenge of our time.” Recommended responses include promoting whole/minimally processed foods (vegetables, fruits, legumes, whole grains, nuts, seeds, seafood, lean proteins); multipronged policies (front-of-pack labels, taxes/subsidies targeting HFSS products, marketing…”
attribution, article, points to yes. Claim: Experts call UPFs the health challenge of our time and recommend multipronged policy responses.