Clinical Nutritionist Practice Test 2025 - Free Practice Questions and Study Guide

A ketogenic diet is characterized as a high-fat, low-carbohydrate diet. This dietary approach significantly reduces carbohydrate intake, which forces the body to enter a metabolic state known as ketosis. In ketosis, the body becomes highly efficient at burning fat for energy in the form of ketones, which are produced from the breakdown of fats in the liver.

The emphasis on high fat intake (typically comprising around 70-80% of total calories) provides the necessary energy while the drastically reduced carbohydrate intake (generally under 50 grams per day) limits the body’s access to glucose, its preferred fuel source. This transition is key to the ketogenic diet's effectiveness, particularly in contexts such as weight loss and the management of certain medical conditions like epilepsy.

In contrast, a high-carbohydrate and low-fat regimen is not aligned with ketogenic principles, nor is a balanced diet that includes all food groups. A diet restricted solely to proteins does not capture the essence of a ketogenic diet either, as it lacks the critical high-fat component necessary for achieving and maintaining ketosis. Thus, the defining hallmark of a ketogenic diet is its high-fat and low-carbohydrate nature.