The word ketosis often inspires confusion or even alarm in those trying to figure out what causes it and whether or not it is a good thing. Here is a simplified description of ketosis.
Definition of ketosis
Let’s go from an overly simplified definition of ketosis to a moderately simple one. Ketosis means that the body has switched from using carbohydrates as a fuel source to fats, almost exclusively.
But it’s a bit more complicated than that. Ketosis begins when there are not enough carbohydrates in the bloodstream to recharge the glycogen stores in the liver. What is glycogen? The liver makes glycogen from carbohydrates as a kind of quick food source for the body.
The lack of carbohydrates means that the body needs an alternative source of food. So the body uses fat, specifically fatty acids, instead. The liver breaks down fats into ketone bodies, commonly known as ketones. When the liver releases these ketone bodies into the bloodstream for the body to use for energy, this is ketosis.
How does ketosis occur?
When you eat carbohydrates, the body uses them for fuel and converts the rest to fat using insulin. This means that carbohydrates are not actually stored in the body, except those that are stored in the liver as glycogen.
If you use up all the carbohydrates in your bloodstream and don’t replenish them, your body will eventually have to use the fat you’re eating with your food and the fat stored in your body for fuel. It usually takes around 48 hours to induce ketosis.
Diets and Ketosis
A growing number of diets recommend reducing carbohydrate intake, as the modern diet has far more than is needed to fuel the body. Things like bread, pasta, sugar, sodas, candy, and other cereals or sugar-based foods are high in carbohydrates, and are now eaten more often and in larger quantities than ever before.
Both the Atkins diet and the South Beach diet are based on putting a person’s body into a state of ketosis to begin the process of rapid fat loss, as the body must use fat for energy during ketosis.
People following other low-carb diets, such as the Paleo diet (also called the primal or caveman diet), can also go in and out of ketosis based on their daily dietary choices, although inducing ketosis is not the primary goal of these diets.
Is ketosis dangerous?
This topic is hotly debated, but the truly dangerous condition related to ketosis is actually ketoacidosis. The body does not naturally go into ketoacidosis, insulin prevents this. But in people with type I diabetes, the body doesn’t make insulin, so a lack of glucose in the blood can lead to ketoacidosis.