Google “keto diet” and you’ll get well over a million hits. Here’s my Cliffs Notes version, including links for those who wish to jump deeper into the science of nutrition.
Despite keto’s current fad status, the diet’s medical roots are almost a century old. The ketogenic diet was designed in 1924 by Dr. Russell Wilder at the Mayo Clinic, to mimic the metabolism of fasting as a treatment for drug-resistant epilepsy.
Simply put, on a keto diet your body burns fats for fuel instead of glucose (sugar).
The keto diet is very low in carbohydrates, moderate in protein, and high in fats. 70-75% of your diet comes from healthy fats (olive oil, coconut oil, butter, high-fat cream, meats, eggs, some nuts and seeds), 10-20% protein, and 5-10% carbohydrates.
The average American eats about 300g of carbohydrates per day. On a standard keto diet, your net carbs should average 20-30g/day. Net carbs are your total grams of dietary carbs minus the total grams of fiber.
According to a study published in the June 2012 issue of the Journal of the American Medical Association (JAMA), a low-carb diet is more effective than a low-fat diet or low-glycemic Mediterranean-style diet for weight loss.
So how can eating a diet high in fat help you lose fat?
We know what you’re thinking: a concept that defies common sense. It’s inside-out, upside-down.
When you eat high-carb (and sugary) foods, they break down into glucose–the easiest molecule for your body to use for energy. Glucose that isn’t burned is stored as glycogen in the liver and muscles. Any glucose beyond what the liver and muscles can store as glycogen is converted into fat. (Our bodies are remarkably efficient at storing fuel for future use.)
But when carbs are drastically reduced, your body needs another energy source. On a ketogenic diet, your body switches to a metabolic state called ketosis. By breaking down fat, your liver produces ketones, which the body now uses as its primary fuel source.
You’re now running on fat, rather than storing it.
Because of the way we eat today, the American body uses glucose as its primary fuel. And most of us – more than two-thirds of adults and nearly one-third of all children – are either overweight or obese.
We have easy access to ready-to-eat, high-carbohydrate processed foods. And carbs are delicious. Pasta, bread, French fries, cake, cookies, ice-cream, candy, anyone?
Right now you’re probably thinking you can’t live without foods high in carbohydrates and sugar. Well, so did I. Read Why a Carb Addict Went Keto.