Ketones are molecules that your heart, brain and muscles can use for energy, instead of sugar or fat. Most of your cells are actually 25 percent more efficient when using ketones instead of sugar. Having ketones circulating in your blood can help prevent seizures in epileptics and could also help protect you against neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases.
Ketones in Foods
Ketones are not present in foods. Although ketones are a source of energy that almost all of your body cells can use, ketones are actually a byproduct of fat oxidation. In other words, when your body burns fat, it produces ketones that can be used for energy. The more fat your body burns, the more ketones are produced. Although foods do not have ketones, the foods you choose can help you promote ketosis -- the state in which your body uses ketones.
How To Produce Ketones
To get your body to produce ketones, you need to follow a very low-carb, moderate protein and high fat diet. It is only when your daily carb intake drops below 50 g a day that your body produces enough ketones as a result of utilizing fat as its main source of fat. Because the typical U.S. diet provides 250 to 400 g of carbs daily, most people do not have detectable levels of ketones circulating in their blood.
Avoid High-Carb Foods
If you want to have significant levels of ketones in your body to provide an efficient source of energy for your cells, avoid high-carb foods. Grains, such as bread, breakfast cereals and pasta, as well as sugar found in soft drinks, candies and desserts, are too high in carbs for a ketogenic -- or ketone-producing -- diet. You should also avoid potatoes, corn, legumes, most fruits, milk and yogurt. Track your carb intake to make sure you don't get more than 50 g a day. Consult your doctor before making these dietary changes, especially if you have a medical condition or take medications.
Eat More Fat
To help your body burn fat and produce ketones, you will need to get about two-thirds to three-quarters of your calories from fat. Consult your doctor before switching to a ketogenic diet to ensure it is safe for you. For example, a ketogenic breakfast could contain eggs cooked in generous amounts of olive oil, cheese, sausages, spinach, mushrooms and/or cherry tomatoes. A serving of fish, chicken or steak cooked in generous quantities of coconut oil, along with asparagus topped with butter, could be your ketogenic lunch or dinner. Coconut oil contains a type of fat called medium-chain triglycerides -- or MCTs -- that promote the production of ketones.
- Protein Power; "Metabolism and Ketosis"; May 2007
- Food and Agriculture Organization of the United Nations: Chapter 2 -- The Role of Carbohydrates in Maintenance of Health
- USDA National Nutrient Database: Nutrient Data Laboratory
- "The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable"; Stephen Phinney et al.; 2011
- "The New York Times"; "What if It's All Been a Big Fat Lie?"; Gary Taubles; July 7, 2002
- Nutrition and Metabolism Society: Top Ten Low-Carb Myths