What is Keto? - Performance Kitchen

Since Mark Sisson’s 2017 best-selling book, The Keto Reset Diet hit shelves, there’s been a tremendous buzz around “eating keto” and an accompanying surge of keto-friendly products. Some consider this method of eating to have evolved out of the paleo and low-carb movement. Keto shares a similar goal: using stored body fat for energy. Comparatively, keto is low-carb and higher fat. For the non-nutritionist, it can all sound a bit puzzling. So, what is keto, and what exactly does “going keto” involve?

This article will prime you with a basic understanding of the keto (aka, ketogenic) diet, especially for those interested in our new, Carb-Wise, keto-friendly meals. Whether or not a “keto journey” fits your nutrition needs is something worth  discussing with a Registered Dietitian. In the meantime, if you want to learn the key concepts behind eating keto, read on!

Available Energy

To understand the main premise of a keto diet, you need to know how our bodies usually get energy. Typically, we get our fuel from blood glucose–sugars present in our bloodstream–most of which come from the carbohydrates in our daily diet. However, we can also reach a state where the body metabolizes fat at a rapid rate and converts fatty acid into ketones, aka ketosis.

Keto Vocabulary


Ketone bodies are produced in your liver, and The Harvard Medical Dictionary of Health defines them as “substances produced when the body burns fat for energy[…]”.


A metabolic state in which your body burns ketones for energy. You may hear the term keto, ketogenic, ketonic, or ketone-burning used interchangeably in reference to this state. Sisson’s book suggests ketosis should be our usual metabolic state and may have been the default state in which our ancestors once lived and thrived.


It’s important to make a distinction between ketosis and ketoacidosis. The Mayo Clinic describes ketoacidosis as “a serious complication of diabetes that occurs when your body produces high levels of blood acids called ketones.” The condition arises when your body can’t produce enough insulin.


A metabolic state (which most of us are in) whereby we’re fueled by glucose. Carbohydrates are present in many foods, such as grains, starches, dairy, fruits, vegetables, and sweets. These all convert to glucose.


Macronutrients are three core components of a balanced diet: carbohydrates, protein, and fat.


Micronutrients are a combination of nearly 30 vitamins and minerals which must be consumed in sufficient quantities for optimal health. Lack of proper micronutrients can cause major health impact. You’ve likely heard them referred to as essential nutrients.

Net Carbs

"Net Carbs" typically refers to the amount of carbohydrates in a product excluding fiber, or excluding both fiber and sugar alcohols. A simple formula for determining Net Carbs is to take the amount of Total Carbohydrates, and subtract the Dietary Fiber. For example a meal containing 5g of Total Carbohydrates, less 3g of Dietary Fiber will have 2g of Net Carbs.

Going into Ketosis

Ketosis can occur while following a low carbohydrate diet, during fasting, after a period of prolonged heavy exercise, or if you have unmanaged Type I diabetes. If you’re not dependent on high-carbohydrate foods, your body will eventually go into a state of ketosis in approximately two days to one week (depending on your physiology, exercise level, and foods consumed). Your muscles will then burn mostly fat for fuel, and ketones in the liver will be used to support brain function.

Sisson suggests that a keto regimen is an effective way to achieve weight loss, disease protection, and reach your peak athletic and cognitive abilities. The keto diet encourages increasing and varying one’s consumption of fresh, colorful vegetables, and making a shift towards getting a daily ratio of 65-75% fat, 15-25% protein, and 5-10% carbs. Typically, this means complete elimination of all sugar, grains, and starches. Carbohydrate intake may vary depending on your level of activity.