In 1977, a committee of the United States Senate told Americans how to eat. Less fat. Less cholesterol. Less sugar. And more of something the report had to name for the purpose: "complex carbohydrates", a phrase it was the first to use, meaning fruit, vegetables and whole grains. In numbers, it asked Americans to raise carbohydrate from 28% to 48% of what they ate and to cut fat from 40% to 30%. The goals were never a settled consensus, they drew criticism from several sides, and a softer second version followed in 1980. The food pyramid followed, and the advice spread to schools, hospitals and kitchens across the Western world.
What does a diet that supports your health actually look like? Start with someone who has followed the 1977 advice faithfully. Whole grains at breakfast. A big salad at lunch. Lean chicken and brown rice for dinner. Olive oil instead of butter. They have done everything they were told, and they are still tired in the afternoon, stiff when they get up, and puzzled by a digestion that does what it likes.
They followed the instructions correctly. Some of the instructions were wrong. Obedience, it turns out, is not a nutrient.
The saturated fat story
In 1953, Ancel Keys presented a graph. It set the share of fat in the diet against deaths from heart disease in six countries, and the line went up neatly. It was criticised heavily at the time, but it worked. Six dots on a graph went on to redesign the Western kitchen. Keys then led a much larger project, following men in seven countries, and in January 1961 he was on the cover of Time. The idea that saturated fat causes heart disease became official advice, then government policy, then the reason supermarket shelves filled with low-fat everything.
Money helped it along. In 1965, the American sugar industry's own foundation paid for a review of the evidence, later published in the New England Journal of Medicine, that singled out fat and cholesterol as the dietary causes of heart disease and played down the evidence against sugar. The foundation set the review's aim, supplied articles for it and saw the drafts. Its role was not disclosed. The sweetest deal in the history of nutrition.
Then came the long count. In 2010, 21 groups of people, 347,747 in all, followed for 5 to 23 years, were pooled. Of them, 11,006 developed heart disease or had a stroke. How much saturated fat they ate made no difference to their risk of heart disease, stroke, or the two combined.
The practical result of the old advice was a swap. Animal fats such as butter, lard and tallow went out of the food supply, and oils pressed from corn, soya, sunflower and rapeseed came in, labelled as good for the heart. Seed oils became a staple of packaged and fried food, and they still are.
The best test of that swap sat unpublished for decades. In the Minnesota Coronary Experiment, run from 1968 to 1973 in a nursing home and six mental hospitals, 9,423 people ate either a diet high in animal fat or one where corn oil and corn-oil margarine took its place. The corn-oil diet cut cholesterol by 13.8%, and brought no fewer deaths. Better numbers, no extra years. Each 30-point fall in blood cholesterol went with a 22% higher risk of dying. The full results were only recovered and published in 2016.
Two kinds of trans fat
The advice also lumps two different things together. Trans fat is something to avoid, we are told, and so beef and butter fall under suspicion because they contain some.
But there are two kinds. Industrial trans fats are made by partly hydrogenating seed oils, for margarine and shelf-stable baking. Natural trans fats are made by bacteria in the stomachs of cattle, sheep and goats, and end up in their meat and milk fat. When the two were separated in long-running groups of people, the trans fats from ruminant animals were not linked to heart disease. The industrial ones trended towards harm.
Cutting out butter to avoid trans fat removes the kind with no link to heart disease, while the margarine kind stays wherever processed food still uses it. Throwing out the butter to dodge the margarine is a strange kind of caution.
What humans evolved to eat
You will read that the human gut is a carnivore's gut. The real picture is more interesting, and it points the same way.
A review that pulled together 25 separate lines of evidence, from genetics and physiology to archaeology and zoology, concluded that the human lineage climbed from a low position on the food chain to a high, carnivorous one during the Pleistocene, starting with Homo habilis and peaking with Homo erectus. It slid back down later, and the slide ended with farming.
Your stomach agrees. Across mammals and birds, the species with the most acidic stomachs are the scavengers and the carnivores, which need strong acid to kill the microbes on meat. Herbivores have the mildest. The human stomach sits with the meat-eaters. Your stomach never got the memo about the food pyramid.
Farming began roughly 10,000 years ago. Grains, legumes and seed oils, the foods the 1977 advice put at the base of the pyramid, are recent arrivals in a body that spent far longer eating animals.
The nearest thing to a modern test of an all-meat diet is almost a century old. 8 Smart Ways to Fight Cognitive Decline with Food, linked below, has the explorer Vilhjalmur Stefansson and a companion, who ate nothing but meat for a year in the late 1920s under hospital checks, with no sign of ill effects. The meat industry paid for it, and it looked at only two men.
What only animal foods carry
Some nutrients come only, or almost only, from animal foods.
Vitamin B12. Plants do not need it and do not make it. The natural sources are meat, fish, shellfish, liver, eggs and dairy. A diet without them has to replace it.
Vitamin A as retinol. Animal foods carry vitamin A ready to use. Plants carry beta-carotene, which the body has to convert first.
DHA. The main omega-3 fat in the brain is DHA, and it comes from fish and other animal foods. The plant omega-3, ALA, from flax and walnuts, raises other omega-3 fats in the blood but barely moves DHA. Eating DHA itself is what raises it.
Protein you can use. The newer measure of protein quality, the one the UN's Food and Agriculture Organization proposed in 2013, counts how much of each essential amino acid is actually absorbed by the end of the small intestine. Animal proteins score well on it. Plant proteins usually need careful combining to come close.
8 Smart Ways to Fight Cognitive Decline with Food, linked below, has why the brain in particular depends on several of these. 7 Surprising Sources of Vitamin D3 You Need to Know for Better Health has the oily fish, eggs and liver that carry vitamin D too.
The amino acid we throw away
Modern eating keeps the steak and bins the rest: the skin, the cartilage, the bones, the knuckles, the organs. That habit may cost more than it seems.
Glycine is the most common amino acid in collagen, the protein of skin, tendons, cartilage and the gut lining. The body makes its own, and a typical diet adds some. But when every source and every use was added up for an adult, the total available fell well short of what collagen-building alone requires. The authors concluded that glycine is "semi-essential": we need more than we can make.
Glycine is concentrated exactly where modern eating stops: in skin, connective tissue and bones. Lean muscle meat carries far less. So the answer is the old one. Make broth from bones, eat the chicken skin, cook the cheaper cuts that come with their gristle, and eat the animal from nose to tail. Your grandmother's stockpot knew this long before anyone measured it.
Grains and the minerals beside them
Whole grains are sold as the healthy choice. They come with a catch.
Grains, legumes, nuts and seeds store phosphorus as phytic acid, and phytic acid binds tightly to calcium, iron and zinc in the gut and stops much of them being absorbed. Cooking reduces it a little. Soaking, sprouting and fermentation, as in real sourdough, reduce it more. Many traditional ways of preparing grain do exactly this. Plenty of modern whole-grain products skip it. A whole grain can hold on to its minerals better than you can.
Some plants defend themselves more directly. Spinach, rhubarb and buckwheat are high in oxalate, which plants also use as crystals to deter whatever eats them, and in some people a diet rich in it contributes to kidney stones. The green smoothie is not the gentle health drink it looks.
Insulin: one root, many names
Insulin is the hormone that moves sugar out of the blood. When cells stop responding to it well, the body makes more to compensate. That state, insulin resistance, sits under type 2 diabetes, and it goes with fatty liver disease and polycystic ovary syndrome.
High insulin also locks fat away. Insulin tells the body to store energy, not release it, so while it stays high, the fat on your body is hard to burn even when you eat less. A diet built on frequent starch and sugar keeps insulin high for most of the day. A diet built on meat, fish, eggs and natural fats keeps it low.
Cholesterol, the other villain of 1977, is worth a word too. It is the raw material for the body's steroid hormones, including testosterone, oestrogen and cortisol, and for vitamin D.
What ketones do to inflammation
When carbohydrate is low, the liver turns fat into ketones, and the body runs on them. One of them, beta-hydroxybutyrate, does more than supply energy.
In mouse and human cells, it blocked the NLRP3 inflammasome, a switch inside immune cells that sets off a cascade of inflammation, including the kind triggered by the crystals in gout. Fasting and ketogenic diets raise this ketone. It is one possible link between eating this way and less inflammation, though it has yet to be measured in people on the diet.
A Nobel Prize, told right
You may have read that Otto Warburg won a Nobel Prize for discovering that cancer cells feed on sugar. He did find that tumours produce large amounts of lactic acid. But his 1931 prize was for something else: the nature and action of a respiratory enzyme in cells. And there is no good evidence in people that changing your diet starves a cancer. That is a claim this article will not make.
What it looks like on the plate
The foundation is animal food, and fattier cuts rather than lean ones: ribeye, short ribs, pork belly, lamb shoulder, chicken thighs with the skin on. The fat is the fuel, and a meal without it does not hold you for long. Trimming the fat off a steak is like draining the fuel tank to make the car lighter.
The protein is what fills you up. Why People Fail at Weight Loss (And How to Succeed) has the 19 people who doubled the share of protein in their diet, from 15% to 30% of calories, ate about 440 calories a day fewer without being told to, and lost 4.9 kg in twelve weeks.
Organ meats regularly. Liver carries retinol, B vitamins, copper and zinc. Heart and kidney are cheap and good. If liver is hard to face, are freeze-dried grass-fed liver in capsules.
Eggs, cooked in butter or tallow.
Bone broth, for the glycine and the salt.
Oily fish: salmon, sardines, mackerel, for the DHA.
Cooking fats: tallow, lard, butter and ghee for the heat, cold-pressed olive oil for dressing. is the one to reach for when the pan is hot.
A day of it might be eggs and bacon fried in tallow, a ribeye or a lamb shoulder with a mug of broth, sardines or cold leftover meat if hunger turns up in between, and water to drink.
On a budget, the cheap end of animal food does the job: eggs, mince, chicken thighs, tinned sardines and liver. 10 Practical Strategies to Overcome Barriers to a Healthy Lifestyle has the pooled prices: the healthiest diets cost about $1.48 a day more than the least healthy.
What leaves: seed oils in any form, grains and legumes, sugar, and processed food, including the protein bars, plant milks and smoothies sold as healthy. Fruit goes too, for its sugar. Why Processed Food Is Hard to Leave — and When It Gets Easier has the order to take it out in, and when each part of the pull eases.
Eating out is where seed oils hide. Order a plain steak, fish, or a burger without the bun, ask for it cooked in butter rather than the fryer oil, and leave the bread basket where it is.
There are two common versions of this. Keto keeps some non-starchy vegetables, cooked, and low in oxalate. Carnivore removes plants altogether, which also makes it the cleanest possible elimination test: take everything out, then bring foods back one at a time and watch what happens. Paul Saladino's makes the full case for eating the whole animal.
Neither has had the long-term test it deserves yet. Why People Fail at Weight Loss, above, has what exists: keto diets doing slightly better than low-fat ones across 13 tests lasting a year or more, and a survey of 2,029 people eating mostly meat, fish and eggs whose typical BMI fell from the overweight range to the healthy one, as they reported it themselves.
The first weeks
The change brings a rough patch, and most of it has a plain cause.
When carbohydrate drops, insulin drops with it, and the kidneys let go of more salt. Potassium and magnesium follow. That is the headache, tiredness and irritability of the first days. The Quiet Signals of Mineral Deficiency has the "keto flu" in people's own accounts: worst in the first week, gone within four.
So salt your food properly, and drink a mug of salted broth. What to Drink Instead of Plain Water — and What the Popular Alternatives Do to Your Body has why water with salt stays in the body better than water alone. It is not the body rejecting the change. It is the body adjusting how it handles minerals.
If you take medication for blood sugar or blood pressure, the change can alter what you need, so get advice before you start.
The instructions were wrong
Go back to the person who did everything right. Whole grains, lean meat, olive oil instead of butter, and still tired and stiff. Nobody told them that the saturated fat scare rested on a disputed graph, that butter's trans fat was not margarine's, that the bones and skin they threw away held what their joints were built from, or that their grains were holding on to their minerals. They were not failing the diet. The diet was failing them.
The foods the 1977 report pushed to the edge of the plate, meat, eggs, fish and animal fat, are the ones the human body spent most of its history eating. Putting them back in the middle is not a fad. It is a correction.
This week, cook one fatty cut of meat in tallow or butter, make a pot of bone broth from what is left, and see how you feel the next morning.
Want to see what this does to your blood sugar? How to Fix Blood Sugar Spikes Naturally — low-carb, keto and carnivore, the order you eat in, the walk after a meal, and what one short night does.
Want to know what to put on the plate for your brain? 8 Smart Ways to Fight Cognitive Decline with Food — the foods and eating habits linked to a healthier brain as you age.
Know someone eating carefully by the official rules and still feeling tired and stiff? Send them this, and cook them a steak.
Disclaimer: This article is general information. For advice about your own health, talk to a qualified health professional. If you take medication for blood sugar or blood pressure, or have kidney disease, get advice before making a big change to what you eat.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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