How to eat healthy, according to the evidence

Six eating rules, and which scares the studies do not support.

The whole thing in one box

  1.  Eat food that isn't calorie-dense
  2.  Get more fiber: aim for 30 g a day
  3.  Get enough protein
  4.  Cut processed meat
  5.  Don't drink your calories
  6.  Eat less salt

  Don't sweat:  MSG or seed oils at cooking doses. An additive list tells
                you little, though a few earn caution.
                "Ultra-processed" is a rough proxy for what matters:
                calorie density, fiber and protein, and maybe texture.

General population only. If you have kidney disease, inflammatory bowel disease, or take medication that changes how your body handles potassium, the protein and fiber points need a clinician.

Full research behind this post: the findings page.

1. Eat food that isn’t calorie-dense

You eat a steady weight of food each day, not a steady number of calories. Dense food packs more calories into that weight.

Water and fiber undo it: vegetables, fruit, beans, soup, potatoes, lean meat.

Why processed food makes you overeat, and how much is calorie density

Most of the measured overeating came through calorie density and taste, which processing creates. The trial could not tell whether processing adds anything on top.

What drove the extra 950 calories a day in the 2026 ward trial Where the extra ~950 calories a day came from Calorie density +662 Engineered tastiness +158 Processing itself +128, too small to pin down All three together +948 36 people. Grey bar means the trial could not separate it from zero. Source: NIH ward trial, results posted 2026.

2019 ward trial, 20 people: every bite weighed. An ultra-processed diet drove about 500 extra calories a day.
2026 ward trial, 36 people: a dense, engineered-to-taste-good version drove about 950.
2025 UK trial, 55 people: about twice the weight loss, 2% of body weight against 1% in eight weeks.

The 2026 numbers are not yet peer-reviewed. The +128 could be anything from zero to about 265.

Does chewing speed matter on its own?

Probably, but the clean proof is short.

2023 trial, 18 people, density matched: harder-textured food cut eating speed 85% and intake 33%.
2026 texture trial, 41 people, two weeks each: slower-chewing food cut intake 369 calories a day.

Those diets also differed in fat and protein, so texture and composition are tangled together.

2. Get more fiber

Most people eat about half the fiber they should. The highest-fiber eaters die 15% to 30% less often.

US adults average about 16 g a day. Aim for 30 g.
Beans, lentils, oats, whole fruit and vegetables get you there.
Ramp up over a few weeks or you get gas.

Why fiber is the best-supported thing on this list

Fiber has the best long-term evidence here.

Reynolds 2019 pooled 185 long-term studies and 58 trials.
Highest-fiber eaters had death rates 15% to 30% lower.
The trials did not measure death. Fiber moved weight and blood pressure a little: about 0.4 kg and 1 point.

The death half is observational, so high-fiber eaters may just be healthier in other ways.

3. Get enough protein

Protein protects muscle while you lose weight. More protein makes more of the weight you lose fat instead of muscle.

A palm-sized portion at each meal.
Eggs, chicken, fish, Greek yogurt, beans, tofu.
It fills you up less than advertised.

Why protein is here for muscle, not for feeling full

Protein earns its spot for muscle. As an appetite tool it is weak.

2016 trial, 40 overweight men, four weeks, 40% calorie cut.
Higher protein gained 1.2 kg of lean mass and lost more fat. Lower protein gained 0.1 kg.
In a ranking of 38 foods by fullness, protein was the weakest nutrient that still mattered.

An extreme setup. It shows protein protects muscle under stress, not that more is always better.

4. Cut processed meat

Bacon, sausage, deli meat, hot dogs, salami. The diabetes cost beats the cancer cost.

Lifetime risk before and after eating 50 g of processed meat a day Eating 50 g a day, over a lifetime Colorectal cancer ~4% to ~4.7%, up 0.7 points Type 2 diabetes ~40% to ~44%, up 4 points, or up to 14 points on the higher pooled estimates baseline risk added by processed meat Same scale on both rows. Diabetes is far more common, so the same bump costs more. Source: IARC 2015, Li 2024 and Pan 2011 pooled analyses, applied to lifetime risk.

Why "as bad as smoking" is misleading, and why diabetes costs more

Processed meat is “Group 1, same as smoking.” That grouping is about how certain scientists are, not how big the risk is.

Smoking multiplies lung cancer risk roughly 25-fold (Thun 2013). Processed meat moves lifetime bowel cancer risk from about 4% to 4.7%.
Cancer rises about 18% per 50 g a day (IARC 2015). Diabetes estimates run from 15% to 51% per 50 g a day.

The cancer link is better established.

Label trick: “uncured” and “no nitrates added” are marketing. The meat ends up cured either way.

Why "uncured" bacon is cured bacon

The end product is the same.

A survey of 470 retail products found no difference in leftover nitrite.
Celery powder is concentrated nitrate. USDA does not list it as an approved curing agent, and holds it to the same nitrite limits through guidance rather than regulation.

Its nitrate content varies between batches, so the “natural” version is harder to verify.

Which meat, ranked

Fish, then poultry, then lean red meat. The gap between poultry and lean red meat is small. Processed meat is the only one with a clear cost.

Fish: no added heart risk, and no measured benefit either. Two servings a week moved it 0% in the US studies (Zhong 2020).
Poultry: small and shaky. Two servings a week, 4% more heart disease, partly fried chicken. 100 g a day, 8% more diabetes, and that number shrank under other models.
Lean red meat: 100 g every day for life, about 4% to 4.7% bowel cancer if the link is causal. Twice the processed-meat dose for the same bump, and rated “probably”, not “convincing”.
Processed meat: covered above.

The studies behind the ranking

Two large studies measured all four meats the same way.

Zhong 2020: six US long-term studies, 29,682 people, 19 years. Per two servings a week, heart disease was 7% higher for processed meat, 4% for poultry, 3% for red meat and unchanged for fish.
Li 2024: 31 long-term studies, 1.97 million adults. Per 50 g of processed meat a day, diabetes was 15% higher. Per 100 g a day, red meat was 10% and poultry 8%.
WHO’s figure for red meat is 17% more bowel cancer per 100 g a day, if the link is causal. A 14-person panel read the same studies in 2019 and rated that evidence low certainty.

Fatty cuts add saturated fat and calories, which the ranking does not count.

5. Don’t drink your calories

Your body barely notices calories you drink. It does not eat less later to compensate.

Water, coffee, tea.

Why drinking calories doesn't fill you up

Solid calories get eaten back at later meals. Liquid ones don’t.

Separate 10-week study: fructose and glucose drinkers gained similar weight, but fructose put the fat in the abdomen.

That fructose study fed a quarter of all calories as pure fructose, so read it as a mechanism, not as a can of soda.

6. Eat less salt

US men eat about 4,000 mg of sodium a day, women about 3,000. The cap is 2,300 mg, and blood pressure keeps falling below it.

There is no level where the benefit stops. Blood pressure tracks sodium in a straight line from 400 mg to 7,600 mg a day, the whole range trials have tested.
Cutting 1,000 mg a day moves systolic blood pressure 0.4 to 1.4 points. If your pressure is already high, about 2 to 3 points.
Potassium-rich food blunts it. On the DASH diet, heavy in fruit, vegetables and low-fat dairy, the same salt cut moved blood pressure about a third as much.
Fruit, vegetables, beans and potatoes carry the potassium. Seven in ten US men fall short of it.

The studies behind the salt number

The line between salt and blood pressure is straight, with no flat part at either end.

Filippini 2021 pooled 85 trials, over 10,000 people. The fitted curve ran straight from 0.4 to 7.6 g a day.
DASH-Sodium 2001 fed 412 people three salt levels, 30 days each. The steepest drop, 4.6 points, came on the step from 2,460 to 1,520 mg.
A 2021 trial in 600 Chinese villages swapped a quarter of the salt for potassium chloride. The 20,995 people were mostly over 60 with high blood pressure. Strokes fell 14%, deaths 12%. That is less salt plus extra potassium, not salt alone.

The U-shaped studies estimated sodium from one urine sample and a formula. On the same people that formula overstated intake by 1,300 mg a day on average, most at low intakes, and turned the straight line into a U. Below 2,300 mg the evidence is blood pressure, not deaths. No trial of cutting salt alone has moved deaths.

A few foods carry most of the risk

Two products carry most of the heart-disease risk pinned on processed food: processed meat and sugary drinks.

What's left after you take out processed meat and soda

Processed meat and sugary drinks carry nearly all of it.

Three US long-term studies, 2024, about 200,000 people.
Removing them took the risk from 11% higher to no difference for cardiovascular disease overall. Heart attacks alone stayed 6% higher.
A separate 2024 look at two of those cohorts, 114,000 people, found one ready-made category that still shows harm: ready-to-eat meat, poultry and seafood, 13% higher death rate.
In the same studies, ultra-processed bread and cereal went with lower heart-disease risk. For diabetes, refined breads went with higher risk.

Adjusting for overall diet quality shrinks what is left.

What the additive scares rest on

The evidence against additives is thin and mixed. The famous scares rest on animal doses nobody eats.

Seed oils and MSG aren’t additives, but the case against them is just as thin.
Three earn real caution: erythritol, potassium bromate, titanium dioxide.
Organic cuts pesticide residues in urine by about 90%. No study shows that changes your health.
Nobody has run the trial that would clear the rest. Thin evidence is not a clean bill.

The three additives that do earn caution

Three earn caution. Only the first has a human signal at a dose people reach. The other two are precautionary.

Erythritol. 30 g, about one sugar-free drink. All showed stickier platelets, a marker and not a clotting event. Not randomized, 10 per arm.
Potassium bromate. A flour improver that causes kidney and thyroid tumours in rats. Still legal in the US. California bans it from 2027.
Titanium dioxide. A whitener the EU banned in 2022 over unresolved DNA-damage questions.

Animal doses are huge. The human evidence is mixed.

The animal work uses doses nobody eats. The human work is mixed and short.

Mice given polysorbate-80 drank about 75 to 250 times the FDA’s upper-bound estimate of what US adults eat, 10 to 20 mg per kg of body weight a day.
Carboxymethylcellulose, a thickener, was tested on 16 people at 15 g a day, 5 to 11 times that upper-bound adult estimate. Gut bacteria shifted. Inflammation markers didn’t move.
A French study of 100,000 links some emulsifiers to heart disease, diabetes and cancer.

That 16-person trial ran 11 days, too short for inflammation to show.

Source: EFSA 2011 and 2015 intake estimates, Shah 2017 (FDA) adult estimate, Chassaing 2022 trial dose.

Seed oils: no good evidence of harm at cooking doses

No good evidence of harm.

30 studies measured these fats in blood, not from meal recall. More linoleic acid, the main fat in seed oils, went with lower heart-disease death.
A review of 15 trials found virtually no evidence it raises inflammation markers.
The randomized mortality data are null, not protective.

People who eat more seed oil also eat less butter and meat, which adjustment can’t fully remove.

MSG, Red 3, and how these scares get built

Both scares rest on rodent results that do not transfer to people.

MSG. The “makes you fat” evidence traces to 1969 research that injected it into newborn rodents to damage the brain.
Red 3. Revoked by the FDA in January 2025, food uses ending in 2027, under a 1960 law that allows no risk assessment. The FDA wrote that the way it causes cancer in male rats “does not occur in humans.”

Should I buy organic?

Not for your own health, as far as anyone has shown.

Three long-term studies pooled, about 280,000 people analysed: no difference in cancer (0.93, 0.78 to 1.12).
The good reasons are not about you: less antibiotic use in animals, less pesticide on farm workers, more wildlife.

Pregnancy and toddlers are the caveat. Organic produce there is a fair precaution.

The full research behind this post is on the findings page. I’m not a doctor or a nutrition scientist. This is me reading papers and checking whether they say what people claim they say.