Avoid Highly Processed Food

Ultra-processed foods (UPFs) are defined by the NOVA classification system as industrially manufactured products created using substances extracted from foods or synthesized in laboratories, including additives, emulsifiers, flavors, colors, sweeteners, and preservatives, combined to produce ready-to-eat or ready-to-heat products designed for convenience, palatability, and long shelf life. Examples include packaged snacks, soft drinks, reconstituted meat products, instant noodles, sugary breakfast cereals, flavored yogurts, and fast food. They now constitute over 50% of daily caloric intake in the United States and UK.

What separates UPFs from simply unhealthy food is not just their nutritional profile, though that is uniformly poor, but the growing evidence that the processing itself contributes to harm, through mechanisms including food additive toxicity, disruption of food matrix and satiety signaling, promotion of overconsumption through hyper-palatability engineering, and adverse effects on the gut microbiome.

All-Cause Mortality {#all-cause-mortality}

The most comprehensive recent synthesis is a 2024 umbrella review in the BMJ by Lane et al., which analyzed 45 pooled analyses across approximately 9.9 million participants, finding that UPF exposure was directly associated with 71% of 45 health parameters studied. A 2025 dose-response meta-analysis (Liang et al., 18 studies, 1.1 million participants, 173,000 deaths) quantified the mortality relationship precisely: people in the highest UPF consumption category had 15% higher all-cause mortality (HR = 1.15, 95% CI 1.09–1.22) compared to the lowest category. Each 10% increment in the proportion of daily calories from UPFs was associated with a 10% higher all-cause mortality risk (HR = 1.10). This dose-response relationship is particularly important: it means even modest reductions in UPF intake carry meaningful mortality benefit.^[1][2]

Cardiovascular Health

A 2024 study in Lancet Regional Health - Americas (Mendoza et al.) followed over 207,000 participants across three large US cohorts (Nurses’ Health Study, NHS II, and Health Professionals Follow-Up Study) for decades, documenting 16,800 incident cardiovascular disease events, 10,401 coronary heart disease cases, and 6,758 strokes. Higher UPF intake was significantly associated with risk across all three cardiovascular outcomes. A concurrent meta-analysis extending these findings confirmed the associations across diverse populations. The BMJ umbrella review found the CVD mortality risk ratio for UPF exposure to be 1.50 (non-dose-response analysis), a 50% increase, making this one of the most dramatic observed diet-CVD relationships in the literature.^[1][3]

Metabolic Health

The BMJ umbrella review rated the association between UPF exposure and type 2 diabetes as convincing (Class I evidence), with a dose-response RR of 1.12 per standardized unit of UPF consumption. UPFs are associated with obesity, metabolic syndrome, and poor glycemic control through multiple pathways: they are typically energy-dense and nutrient-poor, high in refined carbohydrates and unhealthy fats, low in protein and fiber, and engineered to override normal satiety signals. They are also consistently associated with lower intake of key micronutrients including zinc, magnesium, vitamin D, vitamin C, and B vitamins , creating nutrient displacement alongside excess calories.

Mental Health

One of the most striking recent findings in UPF research is the mental health signal. The BMJ umbrella review found convincing evidence for associations between UPF exposure and anxiety disorders (OR 1.48) and common mental health disorders (OR 1.53). These associations were independently replicated across multiple prospective cohorts. The mechanisms are plausible: UPFs chronically disrupt the gut microbiome (reducing beneficial bacteria, increasing inflammatory species), drive systemic inflammation, and contain food additives such as artificial sweeteners and emulsifiers that may affect neurotransmitter pathways and the gut-brain axis.^[1]

Practical framing: The NOVA framework sorts foods into four groups: minimally processed foods (Group 1), culinary ingredients (Group 2), processed foods (Group 3), and ultra-processed foods (Group 4). Avoiding Group 4 does not require eating “perfectly”; replacing 20% of UPF calories with whole or minimally processed alternatives produces measurable health benefits. Practical strategies: cook from whole ingredients when possible, read ingredient lists (more than 5 ingredients or ingredients unrecognizable as food are UPF markers), and treat packaged products with long ingredient lists as an occasional food rather than a dietary staple.

Cardiovascular Health {#cardiovascular-health}

Reducing UPF intake cuts CVD mortality risk; dose-response confirmed across large cohorts. The evidence and practical framing for this claim are covered in the page narrative above.

Metabolic Health {#metabolic-health}

UPF reduction reduces T2D risk (RR 1.12), obesity, and metabolic syndrome. The evidence and practical framing for this claim are covered in the page narrative above.

Mental Health {#mental-health}

UPF exposure associated with 48–53% increased odds of anxiety and common mental disorders. The evidence and practical framing for this claim are covered in the page narrative above.