Nutrition Diet: How Much Water Does It Take to Flush Out Ketones?

October 14, 2025 •

4 min read

The body loses significant water and electrolytes during the initial phases of a ketogenic diet, a physiological change known as 'keto flu'. This process often leads to questions about how much water does it take to flush out ketones and why proper hydration is essential for managing symptoms.

Quick Summary

Water assists in ketone excretion via urine, but there is no single amount that will definitively 'flush them out.' Hydration is key for managing nutritional ketosis symptoms and is a critical component of medical treatment for diabetic ketoacidosis.

Key Points

Hydration is a supportive measure, not a cure for high ketones: Water helps the kidneys excrete ketones, but it does not fix the underlying metabolic cause of their production.
Nutritional Ketosis vs. DKA is a critical distinction: Mild ketosis is managed with lifestyle choices, while diabetic ketoacidosis (DKA) is a life-threatening medical emergency requiring immediate professional treatment.
Electrolyte balance is crucial on a keto diet: Increased fluid loss means you also lose vital electrolytes like sodium and potassium, which must be replenished to prevent 'keto flu' symptoms.
Listen to your body's signals: Aim for a target fluid intake but also pay close attention to thirst and urine color, which are reliable indicators of hydration status.
Seek medical help for dangerous symptoms: Never attempt to treat signs of diabetic ketoacidosis, such as high blood sugar combined with nausea, vomiting, or confusion, with just water.

Ketones are chemicals produced by the liver when the body breaks down fat for energy instead of glucose. This process, known as ketogenesis, is the basis of a ketogenic diet. While some ketone production is a normal metabolic process, excessively high levels can be dangerous, particularly for individuals with diabetes. Understanding the nuance between nutritional ketosis and the life-threatening condition of diabetic ketoacidosis (DKA) is paramount when considering the role of water.

Understanding Ketones and Hydration

Ketone bodies—acetoacetate, beta-hydroxybutyrate, and acetone—are water-soluble compounds that circulate in the bloodstream. The kidneys filter these waste products from the blood and excrete them through urine. Therefore, increased fluid intake can facilitate their removal from the body via urination. However, the process is not as simple as drinking a specific volume of water to make ketones disappear. It depends heavily on the individual's metabolic state.

The Role of Water in Nutritional Ketosis

When a person transitions to a very low-carbohydrate diet, their glycogen stores are depleted, leading to water weight loss and increased urination. This diuretic effect, combined with decreased sodium intake common on keto diets, can lead to dehydration and electrolyte imbalances. Symptoms such as fatigue, headaches, and muscle cramps are common and collectively known as the 'keto flu'. Proper and consistent hydration, along with electrolyte replenishment, is the primary way to manage these mild symptoms. Drinking more water helps produce more urine, aiding in the excretion of excess ketones and reducing the characteristic 'fruity' breath odor associated with ketosis.

The Critical Difference: Diabetic Ketoacidosis (DKA)

In diabetic ketoacidosis, often a complication of type 1 diabetes, dangerously high blood sugar levels prevent cells from using glucose for energy. The body then produces an overwhelming amount of ketones, leading to a severe acid imbalance in the blood. This is a medical emergency that requires immediate intervention. While hydration is a core component of DKA treatment, it is administered via intravenous (IV) fluids in a hospital setting, along with insulin and electrolyte replacement. Relying on oral water intake to treat DKA is extremely dangerous and ineffective.

How to Approach Hydration for Ketones

For someone in mild, nutritional ketosis, here is a practical approach to hydration:

Listen to your body's thirst signals: Your body is excellent at signaling when it needs water. Drink consistently throughout the day, not just when you feel parched.
Replenish electrolytes: Due to increased fluid loss, it's vital to supplement with electrolytes like sodium, potassium, and magnesium. You can achieve this by adding a pinch of salt to your food, drinking bone broth, or using a quality electrolyte supplement.
Monitor urine color: A good rule of thumb is to drink enough water to keep your urine a light yellow color. Dark urine is a sign of dehydration.
Start with a baseline: A common guideline is to aim for half your body weight in ounces of water per day, and adjust based on activity level and climate.

Water Intake Considerations: General vs. Keto


Factor	General Recommendation	Hydration on Keto Diet
Carb Intake	Higher carb intake helps the body retain water.	Very low carb intake leads to increased initial water loss.
Electrolytes	Typically sufficient from a standard diet.	Increased risk of electrolyte imbalances due to diuresis.
Required Intake	Standard 8 glasses (64 oz) often cited, but varies.	Higher fluid intake is often necessary to compensate for losses.
Side Effects	Standard dehydration symptoms if intake is low.	Exacerbated symptoms like 'keto flu' if hydration is insufficient.
Ketones	Not applicable in a standard diet.	Increased ketone excretion is a secondary benefit of adequate hydration.

The Dangers of Inadequate Hydration with Ketones

Failing to stay adequately hydrated while in ketosis can lead to a cascade of unpleasant side effects and, in severe cases, dangerous health conditions:

Worsened 'Keto Flu' Symptoms: Dehydration intensifies headaches, fatigue, dizziness, and muscle cramps.
Kidney Stones: Chronic dehydration can increase the risk of developing kidney stones, a particular concern for those on a long-term ketogenic diet.
Hypokalemia and Hyponatremia: Diluting electrolytes with excessive plain water can be as dangerous as not drinking enough. Low levels of sodium (hyponatremia) or potassium (hypokalemia) can lead to confusion, dizziness, and heart issues.
Masked DKA Symptoms: For individuals with underlying diabetes, the dehydration from DKA can resemble keto flu, potentially delaying life-saving medical care. A fruity breath is a warning sign of high ketones.

When to Seek Medical Help

Consult a healthcare professional immediately if you experience any of the following, especially if you have a known history of diabetes or are unsure of your ketone levels:

Ketone blood test results of 1.6 mmol/L or higher.
Persistent nausea and vomiting.
Confusion, extreme fatigue, or shortness of breath.
A strong, fruity odor on your breath.
High blood sugar (above 250 mg/dL) combined with any of these symptoms.

Conclusion: The Final Word on Flushing Ketones

Ultimately, there is no magic number for how much water it takes to flush out ketones. While proper hydration is a powerful tool for managing the symptoms of nutritional ketosis and promoting the body's natural excretion process, it is not a cure-all. For individuals with diabetes, the presence of high ketones can signal a medical emergency (DKA) that requires professional treatment with IV fluids and insulin, not just increased water intake. For those safely pursuing a ketogenic diet, listening to your body's thirst cues and maintaining a proper balance of electrolytes are the most effective strategies for staying hydrated and feeling your best. Always consult with a healthcare professional before making significant dietary changes, especially if you have a pre-existing medical condition. For more information on managing diabetic ketoacidosis, visit the Cleveland Clinic website.

Frequently Asked Questions

No, drinking more water does not speed up the process of entering ketosis. It helps manage symptoms like the 'keto flu' by replacing lost fluids and electrolytes, which can make the transition feel smoother, but it doesn't accelerate the metabolic shift itself.

No, you cannot flush out ketones entirely with water alone. While water helps the body excrete excess ketones through urine, the only way to significantly reduce ketone production is to increase your carbohydrate intake, which shifts your body's primary fuel source from fat back to glucose.

Yes, drinking excessive amounts of plain water without also replenishing electrolytes can lead to a dangerous condition called hyponatremia, or low sodium levels. This can cause symptoms like confusion, headaches, and dizziness.

For people with diabetes, blood ketone levels of 1.6 mmol/L or higher indicate a risk for diabetic ketoacidosis and require medical attention. For non-diabetics in nutritional ketosis, consistently feeling unwell with symptoms like vomiting, confusion, or shortness of breath warrants immediate medical consultation.

Mild, nutritional ketosis is a normal metabolic state with moderate ketone levels, typically 0.5-3.0 mmol/L. Ketoacidosis is a life-threatening complication of uncontrolled diabetes with extremely high ketone levels (often >3.0 mmol/L), leading to a severe buildup of acid in the blood.

Besides plain water, you can drink electrolyte-enhanced water (make sure it's sugar-free), bone broth, herbal tea, or coconut water (in moderation due to carbs) to help maintain your fluid and electrolyte balance.

Yes, staying well-hydrated helps reduce the acetone component of ketones expelled through the lungs. By producing more urine, the body can excrete more ketones via the kidneys, lessening the fruity odor on the breath.