Ketones are acidic byproducts produced by the liver when breaking down fat for energy instead of glucose, typically during fasting, low-carb dieting, or insulin deficiency. They act as an alternative fuel source for the body and brain. While low levels are normal, high levels can cause dangerous, life-threatening acidic blood (diabetic ketoacidosis). Role in Metabolism and Uses
- Alternative Energy: When glucose is unavailable (low carb intake or fasting), the body enters a state of ketosis, using stored fat, which the liver converts into ketone bodies for fuel.
- Metabolic Flexibility: They act as a backup energy system for body tissues and the brain.
- Ketogenic Diet: Purposefully inducing high ketone production for weight loss or managing certain medical conditions (like epilepsy).
Health Effects and Symptoms
- Normal Levels: Minor ketone production is safe and normal.
- High Levels (Ketoacidosis): When ketones accumulate, they make the blood acidic and toxic.
- Symptoms of High Ketones (DKA): Nausea, vomiting, abdominal pain, fruity-smelling breath, extreme thirst, deep/rapid breathing, and mental confusion.
- Low Ketones: Typically no symptoms, as this is a normal metabolic state.
Monitoring
- Ketone levels can be checked using urine dipsticks or blood meters, with readings above 1.5 mmol/L (blood) indicating a high risk of ketoacidosis.