Epidemiological evidence and mechanisms

A large and rapidly expanding literature links UPF consumption to adverse health outcomes^{(Reference Srour, Kordahi and Bonazzi5)}. Systematic reviews report that higher UPF intake is consistently associated with increased prevalence of overweight and obesity, larger waist circumference, abdominal obesity and metabolic syndrome and with lower HDL-cholesterol^{(Reference Barquera, Hernandez-Barrera and Tolentino7,Reference Lane, Gamage and Du8)} . Studies from the high-income countries show that greater UPF consumption predicts incident overweight/obesity, hypertension, frailty, cardiovascular events, overall and breast cancer, depression and elevated all-cause and cardiovascular mortality^{(Reference Srour, Kordahi and Bonazzi5,Reference Canhada, Luft and Giatti9)} . Across settings, the direction of association is consistently adverse, and dose–response gradients are frequently observed^{(Reference Canhada, Luft and Giatti9,Reference Martini, Godos and Bonaccio10)} .

Multiple mechanisms plausibly explain these findings. UPF are energy dense and high in rapidly digestible carbohydrates, driving high glycaemic loads and promoting excess energy intake and weight gain^{(Reference Srour, Kordahi and Bonazzi5,Reference Lane, Gamage and Du8)} . They are low in fibre and micronutrients, undermining satiety, glycaemic control and cardiometabolic regulation^{(Reference Martini, Godos and Bonaccio10)}. Their altered structures and textures often facilitate rapid ingestion and reduced Oro-sensory exposure, weakening satiety signalling and favouring larger portion sizes^{(Reference Lane, Gamage and Du8)}. Processing and packaging introduce additional exposures, including contaminants such as acrylamide and chemicals such as bisphenols and phthalates, which have been linked to cardiometabolic and endocrine disruption^{(Reference Seferidi, Scrinis and Huybrechts11)}. Critically, UPF displace minimally processed, protective foods, diminishing intake of cardioprotective nutrients and bioactive compounds and undermining dietary patterns known to prevent non-communicable diseases (NCD)^{(Reference Srour, Kordahi and Bonazzi5,Reference Chen, Chu and Hu12)} . Together, this evidence supports recognition of ultra-processing itself as an independent dimension of dietary risk, not captured by nutrient profiles alone^{(Reference Monteiro, Martínez-Steele and Cannon13)}.

Life-course and equity perspectives

A life-course lens underscores the importance of UPF exposure in childhood and adolescence. Young people consume large and increasing quantities of sugar-sweetened beverages, confectionery, packaged snacks and ready-to-eat meals, particularly in rapidly transitioning food environments^{(Reference Marino, Puppo and Del Bo’4,Reference Barquera, Hernandez-Barrera and Tolentino7,Reference Kaur, Kumar and Kaur14)} . Chile and other Latin American countries growth in sales of ready-to-eat meals and snack products has paralleled rising youth obesity^{(Reference Marino, Puppo and Del Bo’4,Reference Barquera, Hernandez-Barrera and Tolentino7)} . Dietary habits and body-weight trajectories established in childhood tend to persist, and higher UPF intake in youth predicts later weight gain and metabolic risk^{(Reference Lane, Gamage and Du8)}. Given strong links between childhood obesity and adult cardiovascular diseases (CVD), diabetes and some cancers, UPF-rich diets in early life likely contribute substantially to adult NCD burdens^{(Reference Chen, Chu and Hu12)}. Because NCD are chronic and costly to manage, early exposure transforms short-term savings at the checkout into long-term clinical and economic liabilities for families and health systems^{(Reference Kaur, Kumar and Kaur14)}.

Equity is central to this discussion. UPF consumption is socially patterned, with low-income and marginalised groups often relying more heavily on such products due to lower prices per kilocalorie, long shelf life, dense retail availability and targeted marketing, alongside limited access to affordable minimally processed foods^{(Reference Mialon and Gomes6,Reference Seferidi, Scrinis and Huybrechts11)} . As a result, the health and environmental harms associated with UPF risk disproportionately affecting those with the fewest resources, widening existing inequalities in NCD and environmental exposures^{(Reference Chen, Chu and Hu12,Reference Kaur, Kumar and Lakshmi15)} . Any policy response must therefore be designed explicitly to reduce, rather than exacerbate, socio-economic gradients in diet-related health.

Environmental and commercial determinants

UPF also exert substantial environmental and social impacts that are not reflected in their retail price^{(Reference Lane, Gamage and Du8)}. They rely on refined commodities such as sugar and vegetable oils, often linked to deforestation, biodiversity loss and greenhouse gas emissions, and require energy-intensive processing, refrigeration, storage and transport^{(Reference Seferidi, Scrinis and Huybrechts11)}. Extensive plastic and composite packaging contributes to solid waste and chemical pollution, including endocrine-disrupting substances^{(Reference Seferidi, Scrinis and Huybrechts11)}. Because many UPF are discretionary and not required for adequate nutrition, their environmental footprint is largely avoidable; shifting consumption towards minimally processed plant-based foods offers clear co-benefits for health and climate^{(Reference Seferidi, Scrinis and Huybrechts11)}.

The proliferation of UPF is driven by powerful commercial actors. Transnational food and beverage corporations deploy aggressive marketing and branding, including child-targeted advertising, sponsorship and product placement, to embed UPF in daily routines and retail environments^{(Reference van Tulleken16)}. These practices normalise UPF as everyday staples and frame diet as a matter of individual responsibility, obscuring the structural and corporate determinants of food environments. In effect, the low shelf price of UPF is achieved by externalising substantial health and environmental costs to public systems and future generations^{(Reference Seferidi, Scrinis and Huybrechts11,Reference van Tulleken16)} .

Schools as a strategic setting

Schools are a particularly strategic setting for addressing UPF consumption. In this commentary, we focus primarily on low-and-middle income countries (LMIC), where school food environments often remain highly permissive to UPF^{(Reference Kaur, Kumar and Kaur14,Reference Kaur, Kumar and Lakshmi15)} . Children and adolescents spend much of their day in or around schools, where food choices are shaped by canteen offerings, vending machines, nearby retailers and peer norms and where marketing and branding are often visible. Evidence indicates that UPF are deeply embedded in school food environments, displacing home-prepared meals and traditional snacks and reinforcing habits of frequent snacking and sugary drink consumption^{(Reference Kaur, Kumar and Kaur14,Reference Kaur, Kumar and Lakshmi15,Reference Baratto, Hoffman and Valmórbida17)} . This picture contrasts with several high-income countries, where nutritional standards and regulations now severely restrict many UPF in school meals and vending. Because school age is a critical period for habit formation, school-based interventions can have durable impacts on dietary trajectories^{(Reference Kaur, Kumar and Kaur14,Reference Kaur, Kumar and Lakshmi15,Reference Baratto, Hoffman and Valmórbida17)} .

Cluster-randomised trials in India and Brazil show that school-based behavioural interventions and parental education can reduce UPF and added sugar intake and improve diet quality^{(Reference Kaur, Kumar and Kaur14,Reference Kaur, Kumar and Lakshmi15,Reference Baratto, Hoffman and Valmórbida17)} . Effective policy packages typically include bans or strict limits on sugar-sweetened beverages, packaged snacks and confectionery on school premises; nutrition standards for school meals that emphasise minimally processed foods and curriculum-based education on food processing, label reading and marketing literacy^{(Reference Kaur, Kumar and Kaur14,Reference Kaur, Kumar and Lakshmi15,Reference Baratto, Hoffman and Valmórbida17)} . Locating such measures within a broader structural approach, rather than relying on individual advice alone, is consistent with evidence on the commercial determinants of UPF consumption^{(Reference Kaur, Kumar and Kaur14–Reference Baratto, Hoffman and Valmórbida17)}.

Policy implications

The converging evidence on health, environmental and social harms implies that treating UPF as acceptable low-cost staples is no longer tenable. Structural policies are needed to make their hidden costs visible and to rebalance food environments^{(Reference Seferidi, Scrinis and Huybrechts11)}. Most concrete policy experience to date comes from upper-middle-income countries (notably Chile and Mexico), with more limited implementation so far in low-income settings. High-income countries have also adopted some measures, but the mix and strength of policies vary substantially^{(Reference D’Angelo Campos, Ng and McNeel18,Reference Corvalán, Reyes and Garmendia19)} . Chile, Mexico and other Latin American countries have introduced black octagonal ‘high in’ warnings for sugar, salt, saturated fat and energy, backed by nutrient profile models^{(Reference D’Angelo Campos, Ng and McNeel18–Reference Monteiro, Cannon and Moubarac20)}. Prior experience from these countries suggests that nutrient-based warnings can reduce purchases of heavily flagged products and stimulate reformulation. Interpretive front-of-pack nutrition labelling, using nutrient warnings or traffic-light systems, can further help consumers rapidly identify products high in free sugars, saturated fats, Na or energy and partially counter marketing cues^{(Reference D’Angelo Campos, Ng and McNeel18,Reference Corvalán, Reyes and Garmendia19)} . Given the specific concern about processing, there is a strong rationale for complementing nutrient-based labels with indicators of processing level, addressing well-documented difficulties in recognising UPF from ingredient lists alone^{(Reference Monteiro, Cannon and Moubarac20)}.

Marketing restrictions, especially to protect children, represent a second priority. Policies can include banning or severely limiting advertising of UPF high in sugar, salt and saturated fat during children’s programming and on digital platforms heavily used by children, prohibiting child-appealing characters, toys and promotions on packaging and removing brand promotion from schools^{(Reference D’Angelo Campos, Ng and McNeel18–Reference Monteiro, Cannon and Moubarac20)}. Evidence from restrictions on sugar-sweetened beverages and fast food indicates that such measures can reduce exposure and may shift preferences and purchasing patterns. However, many low- and middle-income countries still have minimal or poorly enforced restrictions on UPF marketing, particularly in digital spaces, and there is a paucity of rigorous evaluations from these settings.

Fiscal measures can realign prices with health objectives. Taxes on sugar-sweetened beverages have reduced purchases and prompted reformulation in several jurisdictions; similar approaches could be extended to other UPF high in free sugars or saturated fats, especially if revenues are earmarked for subsidies on fruits, vegetables and minimally processed staples^{(Reference Pagliai, Dinu and Madarena2,Reference Mialon and Gomes6)} . To avoid regressive effects, taxes should be paired with targeted subsidies and social protection to ensure that healthier options are accessible and affordable, particularly for low-income households^{(Reference Mialon and Gomes6,Reference Lane, Gamage and Du8)} .

Finally, environmental and sustainability policies should explicitly incorporate processing, packaging and distribution. Recognising UPF as contributors to greenhouse gas emissions, resource use and waste justifies their inclusion in dietary guidelines and climate strategies^{(Reference Seferidi, Scrinis and Huybrechts11)}. Measures such as extended producer responsibility and restrictions on single-use plastics are likely to disproportionately affect UPF-dominated sectors and can encourage less resource-intensive models of food production and distribution^{(Reference Seferidi, Scrinis and Huybrechts11)}.

Strengths, limitations and research needs

Evidence on UPF and health is remarkably consistent and broad, spanning multiple continents, populations and outcomes. However, most data are observational, leaving room for residual confounding and measurement error. Dietary misreporting, variability in NOVA classification and heterogeneity within UPF categories complicate interpretation^{(Reference Monteiro, Cannon and Moubarac20)}. Mechanistic understanding of specific additives, processing methods and packaging-related exposures remains incomplete, and robust evaluations of UPF-focused policies are still emerging^{(Reference D’Angelo Campos, Ng and McNeel18,Reference Corvalán, Reyes and Garmendia19)} . Future work should refine UPF definitions, improve exposure assessment, deepen mechanistic insight and evaluate the effectiveness and equity impacts of structural policies.