Foods to limit or avoid
In modern populations, what you take out of your diet usually moves the dial more than what you put in. Ultra-processed food, sugar-sweetened drinks, processed meat, and excess alcohol carry the clearest harm signals in modern nutrition science — and they are the easiest changes to make.
The reason removal matters so much is that the modern Western diet has accumulated specific harms that no amount of "extra spinach" can offset. Ultra-processed food displaces both calories and bioavailable nutrients. Sugar-sweetened beverages are the single most consistent dietary input on incident cardiovascular disease, type 2 diabetes, and dementia. Processed meat is a classified human carcinogen. The interventions that produce most of the available longevity dividend cluster around removing or substantially reducing these categories, not adding exotic ones. This article goes through them in order of evidence weight, with the honest summary on the contested debates (seed oils, cheese, saturated fat) at the end.
Ultra-processed food
Evidence rating: Moderate (large, consistent observational dose-response plus supporting controlled-feeding trials; the cohort core carries real residual confounding).
The strongest single dose-response signal in modern nutrition epidemiology. A 2024 umbrella review pooling 45 meta-analyses across roughly 10 million people linked high ultra-processed-food (UPF) intake to 32 distinct adverse outcomes spanning cardiovascular, metabolic, cancer, and mental-health domains.[1] The headline dose-response: each 10% rise in UPF as a share of energy intake associates with roughly 3% higher all-cause mortality (the larger "~10%" sometimes quoted conflates this per-increment figure with highest-vs-lowest comparisons).
The strongest causal anchor is controlled feeding. In the 2019 NIH metabolic-ward trial, adults on an ultra-processed diet involuntarily ate about 500 kcal/day more — and gained weight — than on a minimally processed diet matched for calories, sugar, fat, fibre, and macronutrients, despite eating as much as they liked on both.[2] A 2025 randomized crossover at University College London, published in Nature Medicine, pointed the same way — 55 adults with overweight lost modestly more weight over eight weeks on a minimally processed diet than on an ultra-processed one, both built to the UK Eatwell Guide — though the result is genuinely contested: three Nature Medicine commentaries noted the two arms were not matched on energy density (~2.1 vs ~1.0 kcal/g), that the ~1 kg difference is of limited clinical importance, and that several trial authors have obesity-drug industry ties.[3] The mechanism is plural: a faster eating rate that outpaces satiety signalling, high energy density, gut-barrier disruption from some emulsifiers and additives, and missing phytochemicals from intact food structures.
"UPF" is not monolithic. In a pooled analysis of two large US cohorts (the Nurses' Health Study and Health Professionals Follow-up Study, ~114,000 adults, median ~34-year follow-up), the highest UPF intake carried about 4% higher all-cause mortality (HR 1.04) — driven by causes other than cancer and cardiovascular disease, for which no association appeared — and the signal was concentrated in processed meat (hazard ratios up to 1.43) and sugar-sweetened and artificially sweetened drinks, while whole-grain breads and cereals were neutral.[4] Tellingly, within any given band of overall diet quality the UPF association largely vanished — the company an ultra-processed food keeps matters more than its NOVA label. UPF intake also tracks with accelerated biological aging: each 10% rise in UPF energy associated with +2.4 months of accelerated epigenetic aging (measured by the PhenoAge "aging clock") in the US National Health and Nutrition Examination Survey (NHANES), partly independent of overall diet quality.[5] Because the cohort data are observational and UPF intake correlates with smoking, lower income, and higher body-mass index, residual confounding is real — but the controlled-feeding trials above (the NIH metabolic-ward study, and more tentatively the contested UCL crossover) point to a processing-and-energy-intake pathway that confounding alone does not easily explain.
See Ultra-processed food for the full article — NOVA classification, mechanism, the UCL trial, biological-age effects, and a practical guide to spotting UPF on a label.
Rules of thumb:
- Aim for under 10–20% of daily calories from UPF. The typical Western adult sits at 50–60%.
- Cook from whole or minimally processed ingredients as the default.
- The "kitchen test" on ingredient lists: if a substance isn't something a person could buy in a supermarket for home cooking — modified starches, soy isolates, emulsifiers, hydrogenated fats, dough conditioners, flavour-enhancement agents — the product is ultra-processed.
Sugar-sweetened beverages
Evidence rating: Moderate (consistent large cohorts with a coherent liquid-fructose mechanism; no randomized hard-outcome trials).
The largest single-food-category mortality signal among beverages.
- Each daily 355 mL (12 oz) serving of sugar-sweetened beverage associates with roughly 7% higher all-cause mortality and 10% higher cardiovascular mortality in pooled cohort data.[6]
- One well-known finding is routinely misreported and worth stating correctly: in the Framingham Offspring cohort, the roughly threefold higher rate of incident ischemic stroke and Alzheimer's dementia over a decade attached to daily artificially sweetened soft drinks. Sugar-sweetened beverages showed no association with either outcome in that analysis.[7] The case against sugared drinks rests on the mortality and cardiometabolic data above, not on this study; the diet-drink signal is covered under Sugar substitutes.
- Soft-drink consumption shows a clear dose-response for incident fatty liver disease (metabolic-dysfunction-associated / non-alcoholic fatty liver disease, MASLD/NAFLD): in the Tianjin (TCLSIH) cohort, risk rose from about 18% higher at one serving/week to roughly 47% higher at ≥4 servings/week (HR 1.47) — consistent with the fructose-driven hepatic lipogenesis mechanism above.[8]
- The category includes sodas, sweetened iced tea, energy drinks, sweetened coffee drinks, fruit juices with added sugar, and sports drinks (in non-athletes).
- The World Health Organization (WHO) recommends keeping free sugars under 10% of total energy (strong recommendation) and ideally under 5% (~25 g/day for an average adult; conditional); the American Heart Association (AHA)'s daily caps are 25 g for women and 36 g for men. The 2025–2030 US Dietary Guidelines dropped the daily percentage ceiling altogether, saying "no amount of added sugars … is recommended" and capping any single meal at 10 g[9]. The cardiometabolic case rests mainly on the beverage cohort and trial data above; the threshold recommendations themselves are graded moderate-to-very-low.
The mechanism isn't only the sugar load — it's the liquid delivery. Liquid fructose bypasses satiety regulation and arrives at the liver fast enough to overwhelm normal handling, driving hepatic lipogenesis. The same fructose dose in whole fruit, with its fibre matrix slowing absorption, doesn't produce the same metabolic insult — in fact, whole-fruit consumption tracks with lower cardiovascular and all-cause mortality in the same cohorts where free sugars track with higher.
Diet sodas and other non-sugar sweeteners. Less harmful than the full-sugar versions in the short term, but not biologically inert. The ELSA-Brasil cohort (12,772 adults, ~8 years) found the highest intake of low- and no-calorie sweeteners associated with measurably faster declines in global cognition, memory, and verbal fluency — equivalent to ~1.3 years of accelerated cognitive aging.[10] Erythritol and xylitol — the dominant sugar alcohols in "keto" and "sugar-free" products — show ~2× higher three-year rates of major cardiovascular events in the highest plasma quartile in Cleveland Clinic cohort data, with platelet-reactivity mechanism in vitro.[11][12] Plain water, unsweetened tea, sparkling water, and unsweetened coffee are better defaults. See Sweeteners for the full discussion.
Processed meat
Evidence rating: Strong for the colorectal-cancer classification (IARC Group 1); Moderate for the cardiometabolic and dementia associations.
Classified by the WHO's cancer agency (the International Agency for Research on Cancer, IARC) as a known human carcinogen (Group 1) — the same category as tobacco and asbestos, though the absolute risk is much smaller.
- Definition: meat preserved by smoking, curing, salting, fermenting, or with added chemical preservatives. Bacon, sausages, hot dogs, ham, salami, deli meats, jerky.
- Each 50 g per day of processed meat associates with a 16–18% increase in colorectal cancer risk.[13]
- About 15% higher type 2 diabetes risk per 50 g/day of processed meat (HR 1.15, 95% CI 1.11–1.20 — the bracketed range is where the true effect most plausibly lies, and because it sits entirely above 1.0 the increase is unlikely to be chance), in a federated meta-analysis of 1.97 million adults across 31 cohorts in 20 countries; the same analysis found about 10% higher risk per 100 g/day of unprocessed red meat (HR 1.10, 1.06–1.15).[14] The signal on all-cause, cardiovascular, and cancer mortality is markedly steeper than for unprocessed red meat.[15]
- Dementia signal: a 2025 Harvard cohort analysis in Neurology of over 133,000 adults found that as little as a quarter-serving per day of processed red meat associated with a 14% higher risk of cognitive decline and 13% higher dementia incidence; each additional daily serving correlated to ~1.6 years of accelerated cognitive aging.[16]
- Processed meat carries roughly 4× the sodium of unprocessed red meat per serving, plus elevated nitrates, nitrites, and pre-formed nitrosamines — epidemiologically explaining about two-thirds of the differential cardiovascular risk between processed and unprocessed forms.[17]
- The carcinogens implicated include N-nitroso compounds (from nitrite preservatives), heterocyclic amines (from high-heat cooking), and polycyclic aromatic hydrocarbons (from smoking). Sodium load contributes separately.
Practical: treat processed meat as an occasional indulgence, not a regular diet item. The World Cancer Research Fund (WCRF) guidance is to consume "very little, if any" — there is no established safe threshold, and risk rises monotonically from low intake.[18]
See Red and processed meat for the full article — the processed-vs-unprocessed distinction, the NutriRECS controversy, the Neu5Gc xenosialitis and TMAO mechanisms, cooking-method mitigation, substitution analysis, and the APOE4 paradox.
Unprocessed red meat
Evidence rating: Moderate — the dose-response is real but weaker than for processed meat, population-dependent (present in US cohorts, often absent in European and Asian ones), and Mendelian-randomization studies have so far found no causal link.
Classified by IARC as probably carcinogenic to humans (Group 2A) — weaker evidence than processed meat but still consistent.[19]
- Each 100 g/day of unprocessed red meat associates with about 11% higher cardiovascular disease (CVD) risk (HR 1.11, 1.05–1.16) in a 2023 meta-analysis of 43 studies pooling ~4.4 million adults,[20] and about 10% higher type 2 diabetes risk per 100 g/day in the 1.97-million-adult federated analysis above.[21] For colorectal cancer, a 2025 meta-analysis of 60 prospective cohorts put red meat at about 15% higher risk comparing the highest with the lowest intake (HR 1.15, 1.10–1.21).[22] These are all steeper for processed than for unprocessed forms — see the deep-dive for the full processed-vs-unprocessed asymmetry.
- The cardiovascular signal is partially confounded by saturated fat content, but two distinct human-specific mechanisms operate independently of lipids: Neu5Gc (a non-human sialic acid that triggers chronic low-grade autoimmune-like inflammation, "xenosialitis") and TMAO (a pro-atherogenic metabolite produced when gut microbes convert meat-derived carnitine and choline). See Red and processed meat for the mechanistic detail.
- The NutriRECS controversy (a 2019 five-paper series in Annals of Internal Medicine) argued the underlying evidence is weaker than dietary guidelines suggest.[23] The methodological argument was about applying GRADE to observational nutrition — a framework that structurally guarantees a "low-certainty" verdict in this field. The NutriRECS meta-analyses themselves still found 13% lower total mortality, 14% lower CVD mortality, 11% lower cancer mortality, and 24% lower type 2 diabetes risk with meat reduction.[24] The WHO, the AHA, and the Harvard Chan School pushed back hard.[25] The 2022 Nature Medicine "Burden of Proof" re-analysis applied a more conservative log-linearity assumption and found the dose-response real but with wide uncertainty.[26]
Practical: 1–3 servings per week (roughly 350–500 g cooked weight, aligned with the WCRF upper bound) is a defensible cap. Substitute thoughtfully — the meta-analysis of substitution shows the strongest coronary-heart-disease risk reductions when red meat is replaced by nuts, legumes, poultry, eggs, or dairy, not refined carbohydrates.[27] If you eat red meat, choose lean cuts; cook gently (stew, braise, slow-roast) rather than charring; and co-consume with fibre, which suppresses the cutC gene in the gut microbiome and blunts the post-meal TMAO spike.[28] The Protein article covers the methionine-balance argument; the full article above covers everything else.
Cheese
Evidence rating: Weak / observational — both the cardiovascular-neutral finding and the brain-specific cognitive concern rest on cohort data, not trials.
The MIND diet (the Mediterranean–DASH Intervention for Neurodegenerative Delay — a hybrid of the Mediterranean and DASH, or Dietary Approaches to Stop Hypertension, patterns, emphasizing greens, berries, and fish) recommends less than one serving of cheese per week, based on the original observational cohort. The wider picture is more nuanced.
- The food-matrix argument: Multiple cohort meta-analyses show neutral or slightly favourable cardiovascular associations for cheese consumption — likely because the calcium, vitamin K2, fermentation byproducts, and intact lipid-protein matrix attenuate what would otherwise be a clear saturated-fat-driven elevation in low-density lipoprotein (LDL) cholesterol.[29]
- The MIND-specific concern is about the brain, not the heart. The original MIND cohort placed cheese in the "limit to less than one serving per week" list — based on the observation that higher cheese intake correlated with worse cognitive trajectory. The proposed mechanism is saturated-fat-mediated low-grade inflammation at the blood-brain barrier rather than a generic cardiovascular signal.[30]
Reasonable interpretation:
- Modest cheese intake (1–3 servings/week) is compatible with Mediterranean and most longevity-oriented patterns.
- Hard, fermented cheeses (parmesan, gouda, gruyère) appear to behave better than processed cheese products.
- The MIND <1/week guidance is brain-specific and based on observational data — it's not a hard rule against cheese, and a healthy adult eating modest cheese in a Mediterranean pattern is not contradicting the evidence.
- Cheese in volume daily — particularly highly processed cheeses with added oils and salt — is genuinely worth limiting.
Industrial seed oils — the contested debate
Evidence rating: Moderate — biomarker meta-analyses, RCTs, and the Cochrane fat reviews consistently fail to show harm from linoleic acid at dietary intakes, and point the other way.
The "seed oils are toxic" framing has become popular online. The actual evidence is more boring than either camp suggests.
What's true:
- Industrial deep-frying produces oxidized lipid species that are measurably pro-inflammatory.
- Repeatedly heated oils (commercial fryers running hours daily) are clearly harmful and a real exposure issue.
- Refined oils are calorie-dense and easy to over-consume specifically because they're hidden inside ultra-processed foods.
What's overstated:
- Linoleic acid (the dominant omega-6 in seed oils) at typical dietary intakes is not "inflammatory" in human RCTs and biomarker meta-analyses. Higher biomarker-confirmed linoleic-acid intake associates with neutral or favourable cardiovascular outcomes.[31]
- A 2025 umbrella review pooling 150 cohort meta-analyses found higher dietary intake and circulating levels of omega-6 fatty acids associated with lower risk of cardiovascular disease, several cancers, and all-cause mortality.[32]
- Decades of pooled cohort data and the Cochrane fat-and-cardiovascular reviews show that replacing saturated fat with polyunsaturated fat from vegetable oils reduces cardiovascular mortality, not the reverse.
Practical synthesis:
- Olive oil, especially extra-virgin (EVOO): best evidence; the preferred default for cooking and dressing.
- Avocado oil and nut oils: fine, useful for higher-heat cooking.
- Canola, sunflower, safflower: neutral; not "toxic" in normal dietary use.
- Avoid the oils used in repeated commercial deep-frying (typical fast-food chains, not your home pan).
The headline isn't "avoid seed oils." It's "avoid ultra-processed foods that contain seed oils alongside refined sugar, refined flour, and additives." The ultra-processed context is what's harmful — the oil molecule by itself is mostly innocent. See Dietary fats for the full lipid-quality picture — trans fats, saturated fat substitution dynamics, PUFAs, MUFAs, eggs, and the omega-6:omega-3 ratio.
Coconut oil is the mirror-image myth — marketed as a health food rather than a toxin. A meta-analysis of clinical trials found coconut oil raises LDL cholesterol by ~+10.5 mg/dL relative to non-tropical vegetable oils, without any weight or glycemic benefit.[33] The net message is the same even-handed one applied to seed oils, inverted: coconut oil is not a "health food," but it is not uniquely toxic either — use it sparingly and prefer olive oil as the default.
Trans fats
Evidence rating: Strong — consistent cohort data, a clear mechanism, and confirmatory population outcomes after industrial-trans-fat bans.
Industrial trans fats are unambiguously harmful. Each 1% increase in trans-fat energy associates with roughly 6% higher all-cause mortality and 6% higher cardiovascular mortality;[34] the structural geometry of the trans double bond is biologically alien and disrupts endothelial function, lipid homeostasis, and (within seven weeks of exposure in young adults) DNA methylation at inflammatory loci.
- Between 1990 and 2021, the age-standardised mortality burden attributable to high trans-fat intake fell by ~69% globally, driven by industrial-trans-fat bans in high-income regions.[35]
- As of WHO's 2024 progress report, 53 countries had best-practice trans-fat policies covering 3.7 billion people (46% of the world's population), expected to save ~183,000 lives per year — up from 6% coverage in 2018. But ~5 billion people remain unprotected, and industrial trans fat still causes up to 500,000 premature coronary deaths per year worldwide.[36]
- Mostly eliminated from the food supply in the European Union and the United States since the FDA's 2015 final determination on partially hydrogenated oils (compliance complete by 2018–2020) and the EU's 2019/649 regulation (capping industrial trans at 2 g per 100 g of fat from 2021).
- Still present in some processed foods in countries without similar regulation; check labels for "partially hydrogenated oil" in non-regulated markets.
- Naturally occurring (ruminant) trans fats in dairy and meat — chiefly vaccenic acid and conjugated linoleic acid — are biologically distinct from the industrial form and not harmful at typical intakes.
Excessive sodium
Evidence rating: Strong for blood pressure (randomized DASH-Sodium data); Moderate for cardiovascular and gastric-cancer outcomes.
- Population-level sodium excess, mostly from processed and restaurant food rather than the salt shaker, drives hypertension.
- The DASH-Sodium trial (the low-sodium version of the DASH diet) cut systolic blood pressure by roughly 11 mm Hg in hypertensives — comparable to a single antihypertensive medication.[37]
- The World Health Organization target is under 2 g sodium per day (about 5 g of salt). The US average is around 3.4 g per day.
- More than 70% of dietary sodium in Western diets comes from packaged and restaurant foods, not from the salt shaker. Cutting at the shaker is the smallest possible lever; choosing fewer processed foods is the actual one.
The relationship to blood pressure is real and large in salt-sensitive adults (more common with age, in African ancestry, and in people with hypertension or chronic kidney disease) and smaller in salt-resistant individuals. The population-level recommendation skews to the salt-sensitive side because the harm asymmetry favours caution.
The "J-curve" controversy. The PURE study (~102,000 people, 17 countries) reported a J-shaped association, with apparent cardiovascular harm only above ~5 g/day sodium and possible harm at very low intakes.[38] The page does not endorse the J-curve, because PURE estimated 24-hour sodium from a single fasting morning urine via the Kawasaki formula — a method known to manufacture a spurious J-shape, partly because the formula itself incorporates age, weight, and creatinine, which independently predict mortality. Studies using repeated 24-hour urine collections find a graded, near-linear relationship, and much of the apparent low-sodium "harm" is reverse causation (already-ill people eat less).[39] The very-low-intake harm signal is largely a measurement artefact, not a reason to abandon sodium reduction.
Salt and stomach cancer is an independent harm channel: a dose-response meta-analysis of prospective cohorts found +12% gastric cancer risk per 5 g/day of salt, via mucosal damage, endogenous N-nitroso formation, and synergy with H. pylori.[40] An earlier pooled analysis found a similar direction — 68% higher risk in the highest versus lowest salt-intake category.[41] (Evidence grade: Moderate.) Because the sodium-to-potassium ratio may predict cardiovascular outcomes better than sodium alone, favouring potassium-rich whole foods matters as much as cutting salt.
Alcohol
Evidence rating: Strong for cancer (IARC Group 1, no threshold); contested for all-cause mortality.
The minimum-risk dose is at or near zero, particularly for cancer. Alcohol is an IARC Group 1 carcinogen, and the cancer dose-response has no threshold.
- Cancer rises from the first drink. A comprehensive dose-response meta-analysis (572 studies, 486,538 cancer cases) found that even light drinking (≤1 drink/day) raises risk by about 13% for oral and pharyngeal cancer (RR 1.13), about 26% for oesophageal squamous-cell carcinoma (RR 1.26), and about 4% for female breast cancer (RR 1.04); heavy drinking (>50 g/day) raises oral and pharyngeal cancer risk roughly five-fold (RR 5.13) and oesophageal squamous-cell carcinoma nearly five-fold (RR 4.95).[42] For breast cancer specifically, risk rises 7.1% per 10 g/day of ethanol — roughly one daily drink.[43] An estimated 4.1% of all new cancer cases in 2020 were attributable to alcohol, with moderate drinking (<20 g/day) alone accounting for ~104,000 cases.[44]
- The "J-curve" of supposed cardioprotection has largely collapsed. The Global Burden of Disease analysis found that the level of consumption minimizing total health loss is zero, with all-cause mortality and cancer risk rising monotonically; alcohol was the leading risk factor for death and disability at ages 15–49 globally.[45] Mendelian-randomization studies — which use genetic variation to escape the confounding that inflated the old moderate-drinking "benefit" (sick ex-drinkers misclassified as non-drinkers) — find alcohol "not protective for any disease outcome," with each additional daily drink associated with +2.65 mmHg systolic blood pressure and higher risk of hypertension, coronary artery disease, and atrial fibrillation.[46]
The all-cause-mortality question remains genuinely contested as of 2025: the US National Academies review concluded with moderate certainty that moderate consumption is associated with lower all-cause and cardiovascular mortality — while still finding that breast-cancer risk rises about 5% for every 10–14 g of alcohol per day (RR 1.05, 95% CI 1.04–1.06), on a dose-response the review called "likely linear and not J-shaped." Competing reviews and WHO Europe's 2023 position hold there is no safe level. The cancer dose-response is not contested. See Alcohol for the full discussion, the Mendelian-randomization evidence, and the WHO Europe 2023 statement.
Refined grains and glycemic load
Evidence rating: Moderate.
The practical message here is "limit refined grains, white bread, sugary cereals, and potato products" — not "avoid carbohydrates." Glycemic load (GL; quantity × quality of carbohydrate) is a more robust predictor than glycemic index (GI) alone.
- High glycemic load is associated with coronary heart disease — about 5% higher risk per 50-unit increment (RR ~1.05) — and, in dose-response meta-analyses, modestly with all-cause and stroke mortality.
- The largest analyses — the Richard Doll Consortium mega-cohorts (>100,000 each) and the PURE glycemic-index analysis — found higher GI/GL associated with type 2 diabetes, cardiovascular disease, and all-cause mortality, strongest in those with pre-existing CVD.[47]
See Glycemic index for where the GI/GL evidence is strong versus weak.
Cooking- and storage-derived compounds
Evidence rating: Weak / preliminary (mostly mechanistic and animal data, not hard human outcomes — do not over-read it).
- Acrylamide forms in high-heat starchy foods (fries, crisps, coffee, bread crust); it is an IARC Group 2A probable carcinogen with strong animal genotoxicity. But human epidemiology is largely null: a dose-response meta-analysis found no association between dietary acrylamide and any non-gynaecological site-specific cancer, the one exception being lung cancer in smokers.[48] The gynaecological sites are the genuine loose end — a companion dose-response analysis found little or even inverse association with breast cancer, but linear increases in ovarian and endometrial cancer risk, concentrated in never-smokers.[49]
- Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) from charred, grilled, or well-done meat are plausible mechanisms for the red/processed-meat → colorectal link rather than well-established independent exposures. Mitigation: lower-temperature cooking, marinating, and avoiding char and direct flame contact.
- Advanced glycation end-products (AGEs) from dry high-heat cooking: low-AGE diets modestly lower inflammatory markers (CRP, TNF-α) and improve insulin sensitivity in small RCTs, mostly in people with diabetes or obesity, but there are no hard-outcome trials.[50] A reasonable reason to favour steaming, boiling, and stewing over frying and grilling — not a proven longevity lever.
Food contaminants
Evidence rating: Moderate. The message is "minimize and diversify," not "avoid" — fish and whole grains are net-beneficial.
- Methylmercury concentrates in large predatory fish (swordfish, shark, king mackerel, tilefish, bigeye tuna). The net benefit of fish consumption is clearly favourable, so the guidance is species selection, not fish avoidance; the sensitive group is pregnant or breastfeeding women and young children (neurodevelopment).
- Inorganic arsenic in rice (which takes up ~10× more than other grains; brown rice higher than white because arsenic concentrates in the bran) is an IARC Group 1 carcinogen with no safe threshold, though the increment in low-exposure populations is modest. Mitigation: rinse, cook in excess water (~6:1) and drain, and vary grains. Sensitive group: infants fed rice cereal.
- Cadmium (shellfish, organ meats, some leafy and root crops) and aflatoxins (improperly stored nuts, grains, and corn; IARC Group 1, liver cancer, synergistic with hepatitis B) round out the list. Diversifying sources is the main defence.
What's not on this list
- Eggs — earlier dietary-cholesterol concerns largely resolved. Whole eggs at moderate intake (up to 5–7 per week or roughly one a day) are compatible with cardiovascular health for most adults, with a striking geographic pattern: US/Western cohorts show a small positive risk signal (RR ~1.08 per egg/day), Asian cohorts show neutral-to-protective associations (RR ~0.89), and the explanation is the companion foods rather than the egg itself.[51] RCT meta-analyses show that each 100 mg/day increase in dietary cholesterol moves serum total cholesterol by only ~2.2–2.5 mg/dL while the atherogenic ratio of LDL to high-density lipoprotein (HDL) stays stable — the liver compensates by down-regulating endogenous synthesis.[52] Eggs are also the densest dietary source of phosphatidylcholine (the brain-tissue phospholipid and acetylcholine precursor), with ~4× higher bioavailability than synthetic choline bitartrate. Diabetics may warrant a more conservative cap. See Dietary fats for the geographic-paradox detail.
- Saturated fat in moderation from whole foods (yogurt, cheese, eggs, occasional butter) — not the same as saturated fat from processed foods. The "saturated fat causes heart disease" framing has been substantially moderated by post-2017 evidence;[53] the operative variable is the substitution effect — replacing saturated fatty acids (SFA) with polyunsaturated fat cuts cardiovascular disease risk by about 30%, while replacing SFA with refined carbohydrates does nothing.[54] Food matrix matters separately. In a cross-sectional NHANES analysis, a doubling of total SFA intake was associated with +0.42 years of GrimAge2 biological aging, with palmitic (+0.55 y) and stearic acid (+0.43 y) carrying the signal — though the same analysis also flagged monounsaturated fat, so read the clock numbers as suggestive rather than as a verdict on any particular food.[55]
- Coffee, tea — generally favourable cohort and biomarker data; not on the harm list.
- Wine specifically — same risk profile as other alcohol; no special health benefit despite the resveratrol marketing.
- Gluten, dairy, legumes, nightshades — for adults without confirmed allergy, celiac disease, or specific sensitivity, no evidence of harm in cohort or trial data.
The 80/20 framing
The goal isn't perfection — it's the pattern.
- 80%+ of intake from whole or minimally processed foods — vegetables, legumes, fish, nuts, fruit, whole grains, olive oil, fermented dairy.
- Less than 20% from the categories on this list — ultra-processed food, sugar-sweetened beverages, processed and red meat, sweets, alcohol.
That ratio captures almost all of the dietary-pattern benefit available from removal. Going to 95/5 yields diminishing returns and usually costs adherence. The goal is durable change, not optimization of a single week.
Further reading
- Lane MM et al. Ultra-processed food exposure and adverse health outcomes — umbrella review of epidemiological meta-analyses. BMJ 2024.[56]
- Hall KD et al. Ultra-processed diets cause excess calorie intake and weight gain — NIH metabolic-ward trial. Cell Metab 2019.[57]
- Bouvard V et al. Carcinogenicity of consumption of red and processed meat (IARC). Lancet Oncol 2015.[58]
- Johnston BC et al. Unprocessed red meat and processed meat — NutriRECS dietary guideline recommendations. Ann Intern Med 2019.[59]
- Lescinsky H et al. Burden of Proof — health effects of unprocessed red meat consumption. Nature Medicine 2022.[60]
- Malik VS, Hu FB. Sugar-sweetened beverages and cardiometabolic health — pooled analyses. Circulation 2019.[61]
- Pase MP et al. Sugar- and artificially sweetened beverages and the risks of incident stroke and dementia — Framingham Offspring. Stroke 2017.[62]
- Sacks FM et al. Dietary fats and cardiovascular disease — AHA Presidential Advisory. Circulation 2017.[63]
- Marklund M et al. Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality. Circulation 2019.[64]
- Sadeghi R et al. Dietary and circulating omega-6 fatty acids and their impact on cardiovascular disease, cancer risk, and mortality — global meta-analysis of 150 cohorts. Journal of Translational Medicine 2025.[65]
- Kishimoto Y et al. Egg consumption and human health — a comprehensive review. Journal of Poultry Science 2026.[66]
- Fang Z et al. Association of ultra-processed food consumption with all-cause and cause-specific mortality — population-based cohort study. BMJ 2024.[67]
- de Medeiros GCBS et al. Associations of unprocessed and processed meat with cardiovascular disease incidence and mortality — systematic review and meta-analysis. Crit Rev Food Sci Nutr 2023.[68]
- Zhao Y et al. Associations of dietary cholesterol, serum cholesterol, and egg consumption with mortality. Circulation 2022.[69]
- Sacks FM et al. Effects on blood pressure of reduced dietary sodium and the DASH diet (DASH-Sodium). NEJM 2001.[70]
- de Goede J et al. Dairy consumption and risk of stroke — systematic review and updated dose-response meta-analysis. JAHA 2016.[71]
- ELSA-Brasil investigators. Association between consumption of low- and no-calorie artificial sweeteners and cognitive decline. Neurology 2024.[72]
- Witkowski M et al. The artificial sweetener erythritol and cardiovascular event risk. Nature Medicine 2023.[73]
- Witkowski M et al. Xylitol is prothrombotic and associated with cardiovascular risk. European Heart Journal 2024.[74]
- Bagnardi V et al. Alcohol consumption and site-specific cancer risk — comprehensive dose-response meta-analysis. British Journal of Cancer 2015.[75]
- GBD 2016 Alcohol Collaborators (Griswold MG et al.). Alcohol use and burden for 195 countries and territories, 1990–2016. Lancet 2018.[76]
- Li C et al. Meat consumption and incident type 2 diabetes — federated meta-analysis of 1.97 million adults. Lancet Diabetes & Endocrinology 2024.[77]
- O'Donnell M et al. Urinary sodium and potassium excretion, mortality, and cardiovascular events (PURE). NEJM 2014.[78]
- Neelakantan N et al. The effect of coconut oil consumption on cardiovascular risk factors — meta-analysis of clinical trials. Circulation 2020.[79]
- Jenkins DJA et al. Association of glycaemic index and glycaemic load with type 2 diabetes, cardiovascular disease, cancer, and all-cause mortality — meta-analysis of mega cohorts of more than 100,000 participants. Lancet Diabetes & Endocrinology 2024.[80]
- Fang X et al. Landscape of dietary factors associated with risk of gastric cancer — systematic review and dose-response meta-analysis of prospective cohort studies. European Journal of Cancer 2015.[81]
- Filippini T et al. Dietary acrylamide exposure and risk of site-specific cancer — systematic review and dose-response meta-analysis. Frontiers in Nutrition 2022.[82]
- Sohouli MH et al. The impact of a low advanced glycation end products diet on metabolic risk factors — systematic review and meta-analysis of randomised controlled trials. Advances in Nutrition 2021.[83]
- Cardoso BR et al. Association between ultra-processed food intake and biological ageing in US adults (NHANES 2003–2010). Age and Ageing 2024.[84]
For the deep dives that sit underneath this survey:
- Red and processed meat — Neu5Gc, TMAO, cooking-method mitigation, NutriRECS, dementia, APOE4
- Dietary fats — trans, saturated, PUFA, MUFA, eggs, omega-6:omega-3 ratio, epigenetic-clock signals
- Ultra-processed food — NOVA, the UCL crossover, biological-age effects
- Sweeteners — sugar, non-sugar sweeteners, erythritol/xylitol, allulose
- Alcohol — Mendelian randomization, J-curve collapse