Running on ketones

In 1921 a physician at the Mayo Clinic named Russell Wilder proposed a diet for children with epilepsy that nothing else was helping. He'd noticed that fasting reduced seizures, and he reasoned that a diet mimicking fasting might do the same without starvation. Very high fat, very low carbohydrate, moderate protein. Deprived of sugar, the body makes molecules called ketones from fat, and the brain, which normally runs on glucose, learns to run on those instead. It worked. The ketogenic diet is still a standard treatment for drug-resistant epilepsy in children a century later, and it's the one key on this shelf that began as medicine and stayed medicine.

Its modern life as a weight-loss and performance diet began in the 2000s. Under twenty to fifty grams of carbohydrate a day, which means no bread, grains, fruit, starchy vegetables or sugar; fat as most of the plate. People in ketosis report steady energy, reduced hunger, and often rapid early weight loss, much of it water at first. The research on it for weight, type 2 diabetes and some neurological conditions is active and partly promising.

I'll say the honest things. It's the strictest diet on the 180, and most people can't sustain it, which is fine; it was never meant for everyone. The first week can be rough. Anyone on medication, especially for diabetes or blood pressure, should not try it without a physician, because the effects on blood sugar and fluids are fast. And the long-term evidence for healthy people is thin.

What I keep is Wilder's insight: the body has two fuels, and most of us have never used the second. Even without going fully ketogenic, the experience of letting the body burn fat for a stretch, through a lower-carb day or an overnight fast extended to lunch, teaches something about hunger that the sugar-fed body never learns: it passes.