The pro-metabolic school

Born in 1936, Peat grew up in the Pacific Northwest. He earned a PhD in biology from the University of Oregon in 1972, with his dissertation focused on the physiology of aging and the role of estrogen. He taught at universities in Mexico and the US, and from the 1970s onward published a steady stream of articles on metabolism, hormones, light, and nutrition through his own newsletter and at raypeat.com.

He wasn't a celebrity. He answered reader emails into his 80s, in short, direct paragraphs. He passed in November 2022.

Peat's whole framework rests on one belief: a strong, oxidative metabolism is the foundation of health. When the cell can burn sugar through the mitochondria and produce CO2 efficiently, the body is calm, warm, and resilient. When metabolism is suppressed, everything else (mood, hormones, immunity, aging) goes sideways.

Markers he tracked instead of fancy blood panels: body temperature, resting pulse, sleep quality, mood, and how warm your hands and feet stay. Simple, free, and honest.

His most controversial position. Peat argued that ripe fruit, fresh orange juice, white sugar, and honey aren't villains. They're the cleanest fuel for the mitochondria and they lower the stress hormones (cortisol, adrenaline) your body releases when blood sugar drops.

Going low-carb or fasting, in his view, just teaches the body to run on stress chemistry. Short term you feel fine, long term you burn out the thyroid.

Peat's favorite protein sources were milk and cheese, eggs, gelatin and bone broth, lean white fish (cod, haddock), oysters, and liver about once a week. He pushed gelatin hard because it balances out muscle meat: muscle is heavy in tryptophan and cysteine, which can suppress the thyroid in excess, while gelatin is the calming counterweight.

He didn't publish a strict gram-per-pound number. Roughly 70 to 100+ grams a day of high-quality protein, with regular gelatin, was the picture his writing painted.

The other thing Peat hammered for forty years: polyunsaturated fats (PUFA) from soy, corn, canola, safflower, sunflower, cottonseed oil, and fish oil capsules. He linked them to inflammation, blocked thyroid function, suppressed metabolism, and accelerated aging.

His preferred fats were the boring stable ones: butter, coconut oil, beef tallow. Saturated fat was a feature, not a bug.

Peat's earliest work was on estrogen excess. He saw modern life (PUFA, stress, gut endotoxin, plastics) as one big estrogenic soup, and the antidotes as the youth hormones: thyroid (T3), progesterone, pregnenolone, and DHEA.

He preferred T3 over T4-only thyroid medication, recommended topical progesterone (especially for women in their luteal phase and around menopause), and wrote about pregnenolone as a calming, neuroprotective "mother hormone."

Peat treated light as a nutrient. Incandescent bulbs and sunlight on skin support mitochondria; fluorescent and harsh blue LED light stress the body. He wrote about CO2 the same way: as a calming, anti-inflammatory signal, not a waste product. Slow nasal breathing, sparkling water, and altitude all nudge CO2 up.

Peat's worldview in one line. Most chronic illness, in his read, is the long shadow of unmanaged stress: PUFA, endotoxin, cold, fasting, fluorescent light, sedentary screens, chronic cortisol. The cure isn't more discipline. It's warmth, real food, sleep, sunlight, sugar, salt, and calm.

Across decades of writing, the same short list shows up: aspirin with vitamin K2, niacinamide, vitamin E (mixed tocopherols), pregnenolone, progesterone, T3, and occasional caffeine. He never framed any of it as required. They were tools, in the right context, for people whose food and environment alone weren't enough.

• raypeat.com: the full article archive (sugar, PUFA, thyroid, gelatin, progesterone, light, CO2, aspirin).
• Georgi Dinkov ("haidut") on raypeatforum.com and his blog: technical deep-dives extending Peat's work.
• Danny Roddy: the Generative Energy podcast and writing on hair, hormones, and metabolism.
• functionalps.com: accessible summaries of the framework.