The ketogenic diet is low in carbohydrates, such as starches and sugars, and high in healthy fats from meats and fish. Unlike the standard Westernized diet, which contains anywhere from 45 to 65 percent of the calories from carbohydrates, the ketogenic diet limits carbohydrates to only 2 to 4 percent of total calories. A typical meal on the ketogenic diet is similar to the Paleo diet. It includes a 3.5 ounce serving of protein such as meat or fish that has been cooked in natural fats, including olive oil, cream, coconut oil or butter. It is paired with a side dish that usually includes a non-starchy vegetable such as kale or spinach.
Although it is high in fats, the ketogenic diet is particular about the type of fats it recommends. The ketogenic diet avoids hydrogenated fats such as margarine and keeps Trans fat intake to a minimum. Vegetable oils such as canola, sunflower, sesame, and flaxseed should be cold pressed and not heated to high temperatures, which changes their chemical composition. Because of this, the ketogenic diet recommends avoiding these oils for frying. Instead, the ketogenic diet suggests using clean non-hydrogenated lard, coconut oil, ghee, olive oil and beef tallow for frying since they have high smoke points. The ketogenic diet does not allow for starchy vegetables such as corn, potatoes, peas, squashes, tomatoes, carrots and peppers to be consumed.
Because most of its calories come from natural fats, the ketogenic diet is not necessarily a high protein diet. The ketogenic diet suggests adding a small amount of natural fats such as olive oil and butter to whole food meals in place of starchy carbohydrates. The ketogenic diet maintains that when carbohydrates are digested they have an adverse effect on blood sugar levels. Because the body breaks down most carbohydrates into sugar, the ketogenic suggests limiting calories consumed from carbohydrates in order to reduce blood sugar levels. According to the principles of the ketogenic diet, eating a diet that is high in carbohydrates is associated with many chronic diseases.
According to the ketogenic diet, eating more fat and protein promotes fat burning over sugar burning. It also reduces dips in blood sugar levels. When the body switches over from burning sugar to burning fat, it produces ketone bodies or compounds that can be used as a source of energy when glucose is not readily available. The process of having many ketone bodies present within the body is known as ketosis. The purpose of the ketogenic diet is to reduce blood sugar and insulin levels while prompting the body to use fat as fuel. As blood sugar levels drop, ketone bodies rise. This has been associated with a number of health benefits.