Hypoglycemia, or low blood sugar, is defined as a blood glucose level falling below 70 milligrams per deciliter (mg/dL). While the ketogenic diet is often effective at stabilizing blood sugar levels by minimizing carbohydrate intake, episodes of hypoglycemia can still occur. Understanding how to recognize, treat, and prevent these episodes is important for safely maintaining a ketogenic lifestyle.
Identifying the Symptoms of Low Blood Sugar
Recognizing the onset of low blood sugar is the first step toward safe management. Common physical symptoms include shakiness, excessive sweating, and a rapid heartbeat. These are the body’s adrenaline-driven responses to the sudden drop in available glucose.
Cognitive and neurological symptoms can also manifest quickly, indicating the brain is not receiving enough fuel. These signs may present as paleness, dizziness, confusion, difficulty concentrating, or irritability. For those in the early stages of the ketogenic diet, some of these symptoms can sometimes be mistaken for the temporary effects of “keto flu,” making careful monitoring necessary.
Immediate Steps to Raise Blood Glucose
When blood glucose falls below 70 mg/dL, immediate action is necessary to prevent symptoms from worsening. The standard first-line treatment is the “15-15 rule”: consume 15 grams of fast-acting carbohydrate and recheck blood sugar after 15 minutes. If the reading is still below 70 mg/dL, repeat the 15-gram treatment.
While this intervention temporarily pauses ketosis, safety takes precedence, and pure glucose is the fastest way to raise blood sugar. Effective 15-gram options include three to four glucose tablets, a half-cup of regular soda or fruit juice, or one tablespoon of honey or table sugar. Glucose tablets are often the preferred choice because they deliver pure glucose with minimal volume and allow for precise dosing. If a person is unable to swallow or loses consciousness due to severe hypoglycemia, emergency medical help must be called immediately.
Why Hypoglycemia Occurs on a Ketogenic Diet
Hypoglycemia on a ketogenic diet often results from low carbohydrate intake and other metabolic factors. The absence of a large glucose load means the body relies heavily on the liver’s ability to generate glucose through a process called gluconeogenesis. If this process is insufficient or slow, blood sugar levels can fall too low.
Individuals taking blood sugar-lowering medications, particularly insulin or sulfonylureas, face a higher risk because their dosage may be too high for their current low-carb intake. This creates an imbalance where the medication continues to drive glucose out of the blood despite restricted dietary carbohydrates.
Furthermore, a ketogenic diet depletes the body’s glycogen stores, which are the liver’s quick-release reserve of glucose. The liver’s reduced ability to secrete this reserve leaves the body without a rapid counter-regulatory mechanism.
Strategies for Long-Term Prevention
The most important step for long-term prevention is to consult with a healthcare provider to proactively adjust any diabetes medications. The efficacy of the ketogenic diet in lowering blood sugar often requires an immediate reduction in the dosage of insulin or oral hypoglycemic agents. Attempting to manage these medications without medical supervision can be dangerous.
Consistent and adequate intake of electrolytes is important, as imbalances in sodium, potassium, and magnesium can mimic or worsen symptoms of hypoglycemia. Maintaining sufficient protein intake is another proactive measure, as protein provides the necessary amino acid precursors for the liver to perform gluconeogenesis efficiently. This helps ensure a steady, regulated supply of glucose to the brain.
Timing meals around intense physical activity is helpful, as exercise increases glucose utilization and can quickly drop blood sugar levels when glycogen stores are low. Regular monitoring with a glucose meter allows for the tracking of individual responses to food, exercise, and fasting periods. Proactive monitoring helps identify trends and allows for dietary or medication adjustments before a full hypoglycemic episode occurs.