From the Guidelines
Urine ketones greater than 80 mg/dL while following a ketogenic diet is generally expected and not a cause for concern in most healthy individuals. This level indicates your body is in nutritional ketosis, which is the metabolic state the ketogenic diet aims to achieve. When you restrict carbohydrates significantly (typically below 50g daily), your body shifts from using glucose as its primary fuel to burning fat and producing ketones. For most people on a ketogenic diet, ketone levels between 0.5-3.0 mmol/L in blood (which roughly corresponds to moderate to large amounts in urine) are considered optimal for weight loss and other health benefits 1.
However, it's essential to differentiate between nutritional ketosis and ketoacidosis, a potentially life-threatening condition that can occur in individuals with diabetes. Ketoacidosis is characterized by high blood sugar levels, dehydration, and electrolyte imbalances, and can be diagnosed by measuring blood ketone levels, specifically b-hydroxybutyrate 1.
Some key points to consider:
- If you're experiencing symptoms like excessive thirst, frequent urination, persistent fatigue, confusion, or fruity-smelling breath, you should consult a healthcare provider as these could indicate ketoacidosis, particularly if you have diabetes 1.
- Stay well-hydrated while on a ketogenic diet, as dehydration can concentrate ketones in urine.
- Regular monitoring is reasonable, but the presence of ketones alone without concerning symptoms is typically just confirmation that your dietary approach is working as intended.
- Individuals prone to ketosis, such as those with type 1 diabetes or a history of diabetic ketoacidosis, should measure ketones in urine or blood if they have unexplained hyperglycemia or symptoms of ketosis, and implement sick-day rules and/or seek medical advice if urine or blood ketones are increased 1.
From the Research
Urine Ketones and Ketone Diet
- Urine ketones greater than 80 can be an indication of a state of ketosis, which can be achieved through a ketogenic diet 2.
- A ketogenic diet is a diet that is high in fat, moderate in protein, and low in carbohydrates, and is designed to put the body into a state of ketosis, in which it burns fat for energy instead of carbohydrates 3.
- The relationship between ketosis, ketogenic diet, and food intake control is complex, and ketone bodies can have both anorexigenic and orexigenic effects, depending on the context 4.
Measurement of Ketones
- Urine ketone dip tests can be used to measure ketone levels in the urine, and have been shown to be a sensitive and specific test for detecting diabetic ketoacidosis (DKA) and diabetic ketosis (DK) 5.
- The sensitivity and specificity of urine ketone dip tests for detecting DKA were 99% and 69%, respectively, and for DK were 95% and 80%, respectively 5.
Ketogenic Diet and Health
- The ketogenic diet has been shown to be effective for weight loss and improving biomarkers such as serum hemoglobin A1c in patients with type 2 diabetes, but may also have negative effects such as increasing low-density lipoprotein cholesterol levels 3.
- The long-term consequences of a wide adoption of the ketogenic diet by the general population are not well understood, and some experts have raised concerns about its potential impact on cardiovascular health and other outcomes 3.