Ketogenesis is the release of ketones into the body when fat is broken down for energy. When carbohydrate stores are exhausted, cells turn to fat cells for fuel. These fat cells break down and release energy, and ketones are the by-product of that breakdown. Acetoacetate and acetone are usually also released.
Breaking down fat as a source of energy is generally not a normal energy production process. Carbohydrate stores in cells are replenished when carbohydrates are eaten. Eliminating carbohydrate intake for dietary or health reasons may significantly reduce these stores, leading to ketogenesis. Low carbohydrate diets and diabetic diets are two common forms of ketogenic diet.
Low carbohydrate diets are used as a form of weight loss for some dieters. Popular versions will often reduce intake of simple and complex carbohydrates to the point where cells quickly use up all energy stores. When the body starts to break down fat for energy, ketones are released as a result of ketogenesis. As long as carbohydrate levels remain low, fat stores will continue to be used for energy needs in excess of carbohydrate intake.
Diabetic diets may also result in ketogenesis. Another name for carbohydrate energy is glucose. Glucose can be regulated with a controlled carbohydrate diet. Reaction to lower carbohydrate levels in a diabetic diet is often the same as a low carbohydrate diet used for weight loss. Patients trying to regulate blood glucose levels may choose a ketogenic diet.
Ketones may be released either through exhaling acetone or during urination. Ketones tend to have a sweet smell on the breath. Passing ketones out of the body through urination or exhaling is not known to cause health problems. Increased water intake is often needed to flush acetone from the body.
Ketogenesis is not the same as ketoacidosis. Ketoacidosis is typically associated with alcoholism and diabetes. This condition can result in kidney failure and death if left untreated. Ketoacidosis is a severe form of ketosis that can cause blood pH levels to drop below 7.2. There are no known cases of ketogenesis causing a drop in blood pH levels.
Debate over effects of ketogenesis on the body has resulted in several medical research teams evaluating effects of ketosis on cholesterol levels, overall health, and weight loss. As of 2010, ketogenesis has been found to be a healthy reaction in the body. No negative health-related side effects have been associated with cells using fat for energy in place of carbohydrate stores.