The ketogenic diet, or keto for short, is a way of eating that flips your body's energy source on its head. Instead of burning carbohydrates for fuel, your body starts burning fat. This is achieved by drastically reducing your carb intake and replacing it with fat.

Unlike many diets that focus on cutting calories or fat, the keto diet centers on changing the type of fuel your body uses. On a standard diet, carbohydrates from foods like bread, pasta, and sugar are broken down into glucose, which is the body's preferred and most accessible energy source.

When you significantly limit carbohydrates, your body's glucose reserves run low. With its main fuel gone, it needs an alternative. The liver begins to break down fats into molecules called ketone bodies. These ketones then travel through the bloodstream and are used by your brain, muscles, and other tissues for energy.

This metabolic state is what defines the diet.

To achieve ketosis, you have to follow a specific macronutrient ratio. Macronutrients, or "macros," are the three main nutrient categories: fats, proteins, and carbohydrates. The keto diet's structure is very different from a typical Western diet.

This starkly contrasts with standard dietary guidelines, which typically recommend a much higher percentage of carbohydrates.

The ketogenic diet isn't new. It was originally developed in the 1920s as a medical therapy to treat epilepsy in children. Researchers discovered that fasting helped reduce seizures, and the keto diet was designed to mimic the metabolic effects of fasting without complete food deprivation.

For decades, it remained a specialized medical treatment. It was only in the late 20th century that it gained attention for other potential applications, eventually becoming the popular diet it is today.

Now you know the basics of what the keto diet is, how it works, and where it came from.