Ketosis is a metabolic state that occurs when you have an insufficient amount of stored carbohydrate to provide energy to the brain and red blood cells. Ketosis is the process of fat stores being broken down into ketones to supply the necessary energy. If you are following a very low-carb or specifically ketogenic diet, you are likely to experience a range of symptoms.
How Ketosis Happens
Ketosis typically happens when you are following a low carbohydrate diet, or to a lesser degree if you don't eat sufficient amount of carbs for a day or so. Entering mild ketosis, particularly overnight between meals, is completely normal. If your body uses up all its available energy and glycogen you get from carbohydrates, it starts breaking up fat molecules for energy instead. The liver uses the resultant fatty acids to create ketones, bodies of energy, which can be used by the brain, nervous system and red blood cells.
One of the key indicators for ketosis is the state of your breath. There is a diverse and concentrated range of organic compounds in human breath, which can demonstrate what is going on inside your body. Acetone, for example, is a ketone produced when fatty acids are metabolized for energy. Your body wants to excrete the increased acetone, so it releases it on the breath. This can lead to your breath smelling either like fruit, or having a metallic scent like nail-polish remover. This depends on the severity of your ketosis. If your breath is extremely acetone-heavy, you may be approaching ketoacidosis in which the concentration of ketones in your blood is too high and can poison your body. This is dangerous and requires medical attention.
If you are in ketosis consistently, you will begin to excrete acetone in your urine as well. You can test for acetone in your urine by purchasing special testing strips. The bulk of the acetone produced is removed with your breath, but small amounts are excreted in the urine if the liver is unable to break it down into smaller, less harmful sugars, according to the Agency for Toxic Substances and Disease Registry website.
Going into ketosis can cause weight loss, which can be a reason to try to achieve it. While pungent breath and urine are the most common indicators of ketosis, the School of Medicine at the University of New Mexico outlines a variety of other symptoms including constipation, which is common, as well as hypoglycemia, or low blood sugar, if you are particularly active. More serious conditions include hypercholesterolemia, a high fat concentration in the blood, and hyperacidosis, which occurs when the ketosis becomes severe and the blood starts to become acidic. This is characterized by nausea and vomiting; you should seek medical treatment if this occurs. Other very serious developments include osteoporosis, kidney stones, and pancreatitis.
- Ciba Foundation Symposium: The Regulation of Ketogenesis
- Diabetes Technology and Therapeutics, University of California, Irvine: Breath Ethanol and Acetone as Indicators of Serum Glucose Levels: An Initial Report
- Medline Plus: Breath Odor
- Medline Plus: Diabetic Ketoacidosis
- Agency for Toxic Substances and Disease Registry: Toxic Substances Portal — Acetone
- Experimental and Clinical Cardiology: Long-Term Effects of a Ketogenic Diet In Obese Patients
- University of New Mexico School of Medicine: The Ketogenic Diet