The Ray Peat Guide: Foods, Hormones and Lifestyle

What is the Ray Peat diet?

Ray Peat never published an official diet or food list. This page is my compilation of his positions, sourced from his own articles and interviews, in a quick-reference format. Read his work directly and do your own research. Not medical advice.

The Ray Peat diet, also called pro-metabolic eating or peating, follows one rule: eat foods that raise your metabolic rate and avoid foods that lower it. That means ripe fruit, milk, gelatin, shellfish, saturated fat, salt and sugar. It means avoiding seed oils, most grains, beans, nuts and raw leafy greens.

Who was Ray Peat?

Raymond Peat (1936 to 2022) was an American biologist who spent five decades studying how food, hormones and light change the rate at which cells produce energy. His first degrees were in the humanities, his master's thesis was on the poet William Blake, and he ran a small college in Mexico before returning to the University of Oregon for a PhD in biology with a specialization in physiology. His hormone work began in 1968 with progesterone. He taught at the University of Oregon, Montana State University and the National College of Naturopathic Medicine among other schools, ran a private nutrition counseling practice, published a newsletter for decades and painted in oils. He died on November 24, 2022, at 86.

• 1936Born in Santee, California. His family moved to southern Oregon during the Second World War.
• 1960Master's thesis on William Blake, before any formal training in biology.
• 1962Founded Blake College in Valle de Bravo, Mexico, and ran it until 1965.
• 1968Began his work on progesterone and related hormones.
• 1972PhD in biology from the University of Oregon. His dissertation and two papers in Physiological Chemistry and Physics described progesterone as a protector of cell structure and energy.
• 2022Died November 24, at 86. His articles remain online at raypeat.com.

What foods did Ray Peat recommend?

He judged each food by its effect on cellular energy production. A fruit is built to be eaten, so its defenses are low and its sugars available. A seed is built to survive digestion, so it carries enzyme inhibitors and anti-vitamins. Most of his plant verdicts follow from that.

Ripe fruit and fruit juice

In the research he cited, fruit intake tracked inversely with diabetes, while bread and pasta tracked with it. Orange juice was his staple, up to a quart a day, kept away from iron-rich meals because vitamin C raises iron absorption. He warned against two fruits: bananas, for their latex-related allergens, and avocado, for its unsaturated fat.

Milk, cheese and eggs

Milk supplies calcium, protein, sugar and fat in an easily digested form. He wanted calcium high enough to keep parathyroid hormone low, which he tied to less calcification and inflammation. He chose whole milk over reduced-fat, because skim must be fortified and he treated the added carriers as an allergen risk. Cheese does the same job with less iron, a metal he believed adults accumulate. He paired eggs with carbohydrate and salt, since their amino acids push insulin hard. Read more on plant-based milk and sourcing raw milk locally.

Gelatin, broth and the whole animal

His objection was to eating only the muscle. Muscle protein is high in tryptophan, cysteine and methionine, a pattern he said mimics stress, raising serotonin and suppressing thyroid function. Gelatin is about a third glycine with no tryptophan, so it restores the balance. His figure was roughly 20 grams alongside a half pound of steak, at the same meal. Oysters and shrimp earned a regular place for their copper. Try the beef and gelatin broth bowl or the gelatin gummies.

Saturated fat

Coconut oil, butter, tallow, ghee and cocoa butter, with extra virgin olive oil as the one vegetable oil he called safe. A fat with no double bonds cannot oxidize into the reactive fragments he blamed for degenerative disease. In studies he cited, cocoa butter prevented the heart damage unsaturated fat caused, and animals fed tallow with alcohol had no liver injury. More in the cooking oils guide.

Sugar and salt

Sucrose lowers free fatty acids, which limits the damage stored polyunsaturated fat can do, and its fructose half restrains the insulin surge starch causes. Honey and chocolate sit in the same group. Salt appetite he treated as a reliable signal: restriction raises serotonin and aldosterone, and salty food near bedtime helps sleep. See the electrolyte drink recipe.

Coffee

Coffee supplies magnesium and vitamin B1, drinkers show less thyroid disease, and taken with a meal it blocks iron absorption, which is why he drank it with meat. For people who get shaky from it, his suggestion was about two ounces with cream or milk, taken with food. Read the clean coffee buying guide.

The grey area

Where his position was conditional, or where he never ruled and the community filled the gap.

• Starch. His clearest concession: a high starch diet can work, but better foods should displace it. Well-cooked potato ranks above bread.
• Corn tortillas and masa. The starch he substituted for the others, because students eating only alkali-treated corn showed no starch grains in their blood or urine.
• White rice and sourdough. Neither appears in his articles. Both are starch, and fermentation does not remove starch. Our sourdough piece works through it.
• Liver. Recommended at about one meal a week, because he said it can suppress thyroid function, and he said to buy it fresh.
• Lean pork and lean fish. Allowed in small amounts. The fat is the objection, so leaner cuts carry less of it.
• Macadamia nuts. Never named by him, but the lowest-PUFA nut, which is the only argument for them here.

What foods did Ray Peat avoid?

Seed oils and fish oil, grains, beans, nuts, raw leafy greens, added iron and food gums. Each one either supplies polyunsaturated fat, carries plant defense compounds, or adds a metal or thickener he considered harmful.

Seed oils and fish oil

Soybean, corn, safflower, sunflower, canola, cottonseed, peanut, sesame and flaxseed oil, plus fish oil and cod liver oil. He argued polyunsaturated fats suppress thyroid function, destroy vitamin E, and break down into fragments that block the cell's use of glucose and oxygen. In one study he cited, soy oil fed to nursing rats ended up in their brain cells. On fish oil, see our fish oil article.

Grains, beans and nuts

Seeds carry the plant's strongest defenses: enzyme inhibitors, anti-vitamins and storage proteins with poor amino acid profiles. He said no preparation method makes beans satisfactory, and linked bread and pasta directly to diabetes incidence.

Raw leafy greens

He treated leaves as the plant's least edible part, loaded with compounds that block nutrient absorption, and wrote that only ruminants digest them well. The one raw vegetable he recommended daily is the carrot, because its fiber binds estrogen and bacterial toxins on the way out.

Added iron and food gums

Iron-fortified flour, pasta and cereal, plus black olives colored with iron. He wanted adults reducing iron, not adding it, and paired iron-rich meals with coffee to block absorption. Carrageenan he treated as a known allergen, hidden in ice cream, cream, apple cider, hot dogs and prepared sauces.

What did Ray Peat say about thyroid and hormones?

His position was that most chronic complaints trace back to low energy production. Thyroid function sets that rate, stress hormones and estrogen push it down, and progesterone holds it up.

The steps below follow his argument in order. Each gives his position in plain language, then the article where he made it, and ours where we have covered it.

1. Metabolism sets the frame

   Thyroid hormone controls how fast cells turn food and oxygen into energy. He listed body temperature, pulse, calorie intake at a stable weight, water loss, cholesterol and reflex speed as measures of that rate, and put more weight on them than on blood tests.

   Source: Thyroid, Therapies, Confusion, and Fraud

2. Why he distrusted the standard blood test

   TSH and T4 testing replaced symptom-based diagnosis after 1945. Between 1940 and 1950 the estimated share of hypothyroid Americans fell from 30 or 40 percent to 5 percent, a change he attributed to the test rather than to the people. His own threshold was strict. He wrote that he never saw a person with a TSH over 2 who was comfortably healthy, a figure well below the upper limit most labs use.

   Source: TSH, temperature, pulse rate, and our piece on cholesterol as a thyroid marker

3. How he measured thyroid function at home

   He held that pulse and oral temperature together tell more than either alone. His method was to take both before breakfast, after breakfast and mid-afternoon, and to record them for at least 14 days, roughly the half-life of thyroxine.

   What he said the readings show

   In a healthy person both numbers rise after breakfast, and in a very hypothyroid person one or both fall. Healthy groups average a resting pulse near 85, and less healthy groups near 70. He published no target temperature, so charts of "Peat's temperature targets" are not from his writing.

   Source: TSH, temperature, pulse rate

4. Stress hormones can hide low thyroid

   Adrenaline peaks around 1 or 2 AM and cortisol around dawn, and either can hold a waking temperature and pulse at normal-looking numbers. He described waking in the early hours with a pounding heart, or needing food before falling back asleep, as signs of this pattern, which is why he weighed the change across breakfast more than the waking reading alone.

   Source: TSH, temperature, pulse rate

5. Estrogen belongs with the stress hormones

   He described estrogen as anti-respiratory: it interferes with energy production in the cell and switches on the adrenal stress reaction through the hypothalamus and pituitary. Polyunsaturated fat amplifies the effect, which ties this step back to the food list, and the daily raw carrot was his answer for helping the gut carry estrogen out.

   Source: Estrogen, Age Stress Hormone

6. The protective hormones

   Pregnenolone is the parent compound. The body converts it into progesterone, which he called the most protective hormone it produces, and into DHEA. DHEA has a ceiling, because excess converts to estrogen or testosterone.

   Source: Three Youth-Associated Hormones, and our article on progesterone and heart health

7. How he read menopause

   Menopause, in his reading, is a progesterone failure with estrogen continuing at normal levels, rather than an estrogen deficiency. Unopposed estrogen also obstructs thyroid secretion, which returns the subject to thyroid function in step one.

   Source: Menopause and its causes

Related reading: hypothyroidism and weight loss, the NDT availability problem, and blood sugar control.