Ketones are substances closely allied to acetone, or dimethyl ketone, especially beta-hydroxybutyric acid and acetoacetic acid. These are produced in the body from imperfect oxidation of fats and protein foods. A ketogenic diet is one containing such an excess of fats that acetone and other ketones appear in the urine (ketonuria). It is sometimes used in the treatment of epilepsy and chronic infections of the urinary tract by Escherichia coli. In this diet, butter, cream, eggs and fat meat are allowed, whilst sugar, bread, and other carbohydrates are cut out as far as possible.
Ketosis is one of the symptoms of diabetes; if untreated, a state of coma may ensue and the disease end fatally. It also occurs in the terminal stages of Bright's disease when it is due to failure of the kidneys.