A ketone is a type of organic compound characterized by a carbonyl group (C=O) bonded to two other carbon atoms. Ketones are commonly found in various substances, including some types of sugars and fatty acids. They play a significant role in metabolism, especially during periods of low carbohydrate intake, when the body breaks down fats for energy. One well-known ketone is acetone, which is used as a solvent in many industrial applications and is also found in nail polish remover. Ketones can be produced naturally in the body during the process of ketosis, which occurs when the body relies on fat for fuel instead of carbohydrates.