Review Finds Ultra-Processed Food Health Harms Stem from Ingredients, Not Manufacturing

The three-paper Lancet series on ultra-processed foods, published in November 2025 and authored by 43 international experts, has become one of the most consequential nutrition publications in recent years [1]. Its central argument: the health damage linked to ultra-processed foods (UPFs) is driven primarily by what goes into these products — cheap industrial ingredients like hydrogenated oils, glucose-fructose syrup, protein isolates, and cosmetic food additives — rather than by the manufacturing processes themselves [2].

The distinction matters. If processing is the culprit, then any food that passes through an industrial production line is suspect. If ingredients are to blame, the policy response looks fundamentally different: targeted labeling, ingredient-based taxes, and reformulation mandates become the logical interventions, rather than blanket restrictions on entire categories of processed food.

The Scale of the Evidence

The Lancet series did not emerge in isolation. It builds on a rapidly growing body of research — over 316,000 academic papers have been published on the topic of ultra-processed food, with annual output peaking at more than 45,500 papers in 2023 [3].

Source: OpenAlex

Data as of Jan 1, 2026CSV

The most comprehensive single synthesis preceding the Lancet series was a February 2024 umbrella review published in the BMJ, led by Melissa Lane at Deakin University. That review analyzed 45 unique pooled analyses covering nearly 10 million participants across studies published between 2009 and mid-2023 [4]. It found direct associations between UPF exposure and 32 of 45 health parameters examined, spanning mortality, cancer, cardiovascular, metabolic, gastrointestinal, respiratory, and mental health outcomes [4].

The evidence was classified by strength. Cardiovascular disease mortality showed a risk ratio of 1.50, and type 2 diabetes showed a dose-response risk ratio of 1.12 — both rated as "convincing" (Class I) evidence [4]. Heart disease mortality carried a hazard ratio of 1.66, and all-cause mortality a risk ratio of 1.21, both rated as "highly suggestive" (Class II) [4]. Mental health outcomes were also striking: common mental disorders showed an odds ratio of 1.53, and anxiety 1.48, both at the convincing evidence level [4].

Source: BMJ Umbrella Review 2024

Data as of Feb 29, 2024CSV

What the Lancet Series Actually Says

The Lancet series defines ultra-processed foods as "branded, commercial formulations made from cheap ingredients extracted or derived from whole foods, combined with additives" [1]. The papers identify several specific ingredient categories as drivers of harm: artificial sweeteners, artificial colorants, emulsifiers, hydrogenated oils, glucose-fructose syrup, and protein isolates [2]. The series also raises concerns about chemical contaminants that migrate from packaging — phthalates, bisphenols, and PFAS — which are present at higher concentrations in ultra-processed products [5].

The research confirms that UPF-heavy dietary patterns produce gross nutrient imbalances, with excessive sugar and unhealthy fats paired with insufficient fiber, protein, and health-protective phytochemicals [1]. The series found that associations between UPF consumption and adverse health outcomes "were consistent, strong, and increased with greater UPF consumption" across more than 100 studies, meeting most standard criteria for causality [5].

On policy, the 43 authors called for warning labels, taxes on certain UPFs, restrictions on marketing to children, banning UPFs from schools and hospitals, and using tax revenues to subsidize minimally processed meals for lower-income populations [1][2].

The NOVA Debate: Is Process-Based Classification Still Valid?

The finding that ingredients, not manufacturing, drive harm strikes at the foundation of the NOVA classification system. Developed in 2009 by Brazilian epidemiologist Carlos Monteiro, NOVA sorts foods into four groups by level of industrial processing, with "ultra-processed" as its most restrictive category [6]. The system has been adopted by multiple governments and international bodies as a framework for dietary guidelines.

Critics have long argued that NOVA paints with too broad a brush. A 2025 critical review published in the Proceedings of the Nutrition Society argued that the system "tars all UPF with the same brush, while research suggests not all highly-processed food is the same" [7]. Some foods classified as ultra-processed — certain whole-grain breads, fortified cereals, plant-based milks — have nutritional profiles comparable to minimally processed alternatives [7]. One study found that using ingredient lists for classification increased UPF identification by 30%, with many reclassified foods having nutritional compositions comparable to NOVA Group 1 (minimally processed) foods [7].

The Novo Nordisk Foundation backed a two-year project in 2025 to develop a next-generation food classification system, led by Susanne Bügel at the University of Copenhagen, that would account for nutritional content and food matrix integrity — aspects NOVA ignores [8]. Monteiro objected publicly, writing an open letter stressing the foundation had never had permission to use the name "Nova" and warning that doing so would "cause chaos" [8]. The foundation subsequently dropped the NOVA branding from the project.

A 2025 letter from food scientists went further, calling for UPF and NOVA terminology to "be banned from use by food scientists," arguing that Monteiro's classification was "guided by a clear (health) political agenda" [9].

Defenders of NOVA counter that any classification system involves trade-offs, and that NOVA's simplicity is a feature for population-level guidance, even if it miscategorizes individual products. The Lancet series itself, while focusing on ingredients, did not reject NOVA outright, instead arguing that the classification system remains valid as a research and surveillance tool [5].

The Strongest Case for Processing Itself as a Harm Pathway

The ingredient-focused conclusion does not go unchallenged. Several lines of evidence suggest that industrial processing itself — independent of what ingredients are used — may contribute to health damage.

The most cited evidence comes from Kevin Hall's 2019 randomized controlled trial at the NIH Clinical Center. Twenty healthy volunteers spent two weeks each on an ultra-processed diet and a minimally processed diet, with both diets matched for calories, sugars, fiber, fat, salt, and carbohydrates. Despite the nutritional matching, participants on the ultra-processed diet consumed approximately 500 extra calories per day, ate faster, and gained weight, while those on the minimally processed diet lost weight [10]. Because the diets were nutritionally equivalent, the excess consumption could not be attributed to ingredient content alone.

A 2026 paper in Frontiers in Nutrition offered a mechanistic explanation, arguing that ultra-processing destroys the physical structure — the "food matrix" — of whole foods [11]. The structural collapse accelerates nutrient absorption, suppresses satiety hormones like GLP-1 and peptide YY, and creates what the authors call a "supraphysiological nutrient flux" that overwhelms metabolic organs [11]. Softer textures eliminate the need for thorough chewing, accelerating eating rates before the body can register fullness [11]. The authors argued that nutrition science must move beyond asking "what is in our food" to examining "what has been done to our food" [11].

Process contaminants — neoformed compounds produced when food is cooked or processed at high temperatures — are another pathway. Acrylamide, acrolein, and trans fatty acids form during industrial processing and have been associated with cardiovascular disease [12]. These compounds are not present in the raw ingredients and cannot be attributed to ingredient content.

The Lancet series acknowledged these mechanisms but argued that they are secondary to the ingredient-driven effects, which account for a larger share of the observed health burden across populations [2].

Who Is Most Exposed

Ultra-processed foods now account for the majority of calories consumed in several high-income, English-speaking countries. The United States and United Kingdom lead global consumption, with 58% and 57% of daily calories from UPFs respectively [13]. Germany (48%), Canada (46%), and Australia (44%) follow, while countries with strong culinary traditions built around fresh ingredients — Italy (14%), Brazil (22%) — consume markedly less [13].

Source: Visual Capitalist / Euromonitor / National Dietary Surveys

Data as of Nov 1, 2025CSV

Within countries, the pattern is regressive. Lower-income and less-educated populations consume more UPFs in virtually every country studied [14]. A 2024 analysis found that Americans face a starker trade-off between health and cost than Europeans, with UPF staples dominating mainstream U.S. supermarkets [15]. Children and adolescents are also disproportionately exposed, both through marketing and through institutional food environments — school lunches, convenience stores near schools — where UPFs predominate.

Growth in low- and middle-income countries is accelerating. Between 2007 and 2022, annual sales of ultra-processed foods increased across low-, lower-middle-, and upper-middle-income countries, as multinational food companies expanded distribution networks [16]. A 2025 Lancet analysis found that UPFs are displacing traditional diets worldwide, with the greatest velocity of change in sub-Saharan Africa and South and Southeast Asia [1].

The obesity data tracks these consumption patterns closely. The United States has a 41% adult obesity prevalence, followed by South Africa (31.8%), Australia (30.6%), and Brazil (30.1%) [17].

Source: WHO Global Health Observatory

Data as of Dec 31, 2024CSV

What Ingredient-Based Regulation Looks Like

If ingredients are the primary drivers of harm, the policy toolkit shifts from process-based restrictions to ingredient-specific interventions. More than 50 countries have already implemented sugar-sweetened beverage (SSB) taxes, providing a natural experiment in this approach [18].

Mexico introduced a volumetric SSB tax in 2014 at one peso per liter, producing a 19% reduction in both volume and sugar purchased. The tax was found to be highly cost-effective, saving nearly $4 in healthcare costs for every $1 spent on implementation [19]. The UK's Soft Drinks Industry Levy, introduced in 2018, took a different approach: a two-tiered tax based on sugar concentration, with higher rates for drinks exceeding 8 grams of sugar per 100 milliliters. Manufacturers responded with widespread reformulation, reducing sugar content across the product category before the tax even took full effect [20]. Modeling suggests the UK levy may prevent 12,000 cases of type 2 diabetes and 3,800 cardiovascular disease cases over its first decade, saving £174 million in healthcare costs [20].

A systematic review and meta-analysis found that SSB taxes were associated with an 82% pass-through to consumer prices and a 15% reduction in sales of taxed beverages [19]. However, the evidence on individual health outcomes remains thin, particularly in low- and middle-income countries [21]. A 2025 modeling study on England estimated that extending taxation and warning labels to all foods high in fat, sugar, or salt — not just beverages — could produce substantially larger health gains [22].

The evidence supports setting tax rates between 20% and 40% of the pre-tax price for meaningful health impact, and using revenues to fund complementary policies like healthy food subsidies and public education [19].

The Industry's Fingerprints

Any discussion of whose interests are served by the ingredients-versus-processing framing requires scrutiny of industry involvement in the underlying research.

A 2022 analysis found that 89% of studies criticizing the NOVA UPF classification system were authored by researchers with connections to the ultra-processed food industry [23]. The industry has spent heavily to shape the debate: between 1999 and 2020, ultra-processed food companies spent $1.15 billion on lobbying — more than the gambling, tobacco, or alcohol industries [24].

The conflicts extend to government. An analysis of the advisory committee that shaped the 2020–2025 U.S. Dietary Guidelines for Americans found that 95% of committee members (19 of 20) had at least one connection to the food or pharmaceutical industries, with more than half linked to 30 or more industry actors, including Kellogg, Kraft, General Mills, and Dannon [23].

The Lancet series itself addressed this dynamic directly. Its third paper, on commercial determinants and corporate power, documented how industry activities include direct lobbying, infiltrating government agencies, promoting corporate-friendly regulation, framing scientific debate, generating favorable evidence, and manufacturing scientific doubt [25]. The authors called for limiting corporate political power of food manufacturers and retailers as a prerequisite for effective regulation [25].

This history demands caution. An ingredients-based framing, taken to its logical extreme, could serve industry interests by allowing manufacturers to reformulate products — removing the most harmful ingredients while preserving the ultra-processed product category itself. Whether reformulation produces genuine health improvements or merely shifts the risk profile remains an open and actively researched question. The Lancet series itself acknowledged that "reformulation isn't enough," arguing that structural changes to food systems, not just tweaks to ingredient lists, are necessary [26].

Disease Risks in Context

The strongest ingredient-attributable risk elevations, according to the BMJ umbrella review, cluster around cardiovascular and metabolic disease [4]. Cardiovascular mortality carries a relative risk of 1.50 for the highest versus lowest UPF consumers, and heart disease mortality reaches 1.66 [4]. Type 2 diabetes shows a dose-response relationship, with risk increasing 12% for each increment of UPF consumption [4]. Depression (relative risk 1.22) and anxiety (odds ratio 1.48) round out the most robust associations [4].

Data comparing these risks across income levels is sparse. Most large cohort studies have been conducted in high-income countries — the United States, United Kingdom, France, Spain, Australia — creating a geographic bias in the evidence base [16]. The few studies from low- and middle-income countries suggest that the health effects may be similar or even larger, given that UPF consumption in these settings is often layered on top of existing undernutrition and micronutrient deficiencies, creating a "double burden" of malnutrition [16].

What Comes Next

The ingredients-versus-processing debate is unlikely to be resolved by a single review, however large. Both mechanisms appear to operate simultaneously, and the relative contribution of each may vary by product category, population, and dietary context.

What the evidence does support is that the current pace of policy action is mismatched with the scale of the problem. UPFs account for a majority of calories in the world's largest economies, their consumption is rising fastest where health systems are least equipped to manage the consequences, and the industry that profits from them spends billions to shape the scientific and regulatory landscape.

Whether the response comes through ingredient-based taxes, process-based restrictions, or some combination, the data on harm is no longer seriously in dispute. The argument now is about mechanism and, by extension, about which policy levers to pull — and who gets to decide.