Health Articles

Ketones and Dieting

Most people experience a condition called ketosis when they go from a high-carbohydrate diet to a low-carbohydrate diet. This occurs when ketone molecules are circulating in the blood in a higher amount than on the previous high-carbohydrate diet. Ketosis is a normal physiological state caused by very normal and healthy body functions. Ketosis allows the body to function efficiently and live off of stored body fat when necessary. Ketones are not a poison, which is how most medical and nutritional experts refer to them. Ketones make the body run more efficiently and provide a backup fuel source for the brain. The three substances known as ketone bodies are acetoacetic acid, beta-hydroxybutyric acid, and acetone. Some unknowledgeable people have an absolute fit when told that ketosis produces acetones in the blood, since acetone is a common household solvent. Acetone is commonly used as a fingernail polish remover. The body produces ketones as the preferred fuel for the heart, outer part of the kidneys, and most areas of the brain.

Ketoacidosis is a life-threatening condition commonly associated with type 1 diabetes and insulin-dependent type 2 diabetes. Ketoacidosis is not the same as normal dietary ketosis. The abnormally low level of insulin in the diabetic leads to a toxic build-up of blood glucose causing excess urination, thirst, and dehydration. The glucose cannot enter the cells to produce energy in the absence of insulin. This causes the body to break down an excessive amount of body fat and muscle tissues for energy.

Ketoacidosis is an unhealthy condition in which the body has excessively high glucose and ketone bodies at the same time. The ketoacids lower the pH of the blood to an unhealthy level. The body is very sensitive to changes in blood pH. The condition is never present in a non-diabetic on a carbohydrate-restricted diet in which beneficial ketosis is achieved. Normal ketosis stabilizes blood glucose within a normal range and prevents the breakdown of healthy muscle tissue. The dietary restriction of carbohydrates prevents any build-up of excess glucose. The blood glucose level remains perfectly normal and stable, almost straight line. Dietary fatty acids and ketone bodies are very healthy fuels for the body in contrast to glucose which causes insulin resistance, diabetes, heart disease, and cancer.

Many people falsely believe they cannot or are not losing weight because the ketones drop to a lower level. The keto sticks, used to measure the ketones in the urine, are no longer showing the purple color on the test strip. However, weight loss continues with, or without, the ketones being present. The spillage of excess ketones in the urine disappears on the low-carbohydrate diet after the body becomes accustomed to using dietary fats for energy instead of glucose. This usually occurs within a few weeks on the diet. People who normally eat high-carbohydrate meals have been fueling their bodies with glucose and fructose obtained from the carbohydrates. Their cells have had very little experience burning fatty acids for energy. The body uses the glucose first to prevent high levels of glucose in the blood.

The body experiences a new condition when a person goes on the low-carbohydrate diet. The more commonly used glucose fuel is no longer available. The body reacts by dropping the pancreas' production of insulin and increasing the hormone glucagon. The glucagon draws stored fat reserves in the form of triglycerides for use by the cells as the new energy source. However, the cells are slow to react to this new fuel source, and the individual sometimes feels weak or lacking energy. The resistance to burning fatty acids for energy can vary greatly among individuals. Some people feel this weakness, but others pick right up and take off with the feeling of greater energy than before.


The liver begins to catabolize (break down) the extra fatty acids when they are not being utilized by the cells; however, the liver does not have the enzyme necessary for complete catabolism of the fatty acids. This causes the discharge of the ketone molecules into the blood. The strange taste in the mouth and mild breath odor shows the presence of these ketones. Other body cells can utilize the ketones for energy. The brain can utilize ketones contrary to the myth that the brain must be powered by glucose only; although, some areas of the brain still require glucose which the body makes from amino acids or fats. Ketones are the preferred energy source for the muscles of the heart.

The body begins to utilize the fatty acids for energy more efficiently after a few weeks on the low-carbohydrate diet, and the ketone level drops to normal. This does not mean a person is not losing weight; it means the body is becoming a more efficient fat burner.