If you have just started the keto diet and feel awful, you are not alone. The keto flu is one of the most talked-about side effects of going low-carb, and understanding it can make all the difference.
The keto flu is a collection of symptoms that many people experience in the first one to two weeks of a ketogenic diet. It happens as your body transitions from burning glucose to burning fat for fuel — a process called ketosis.
Symptoms include headaches, fatigue, irritability, brain fog, muscle cramps, nausea, and difficulty sleeping. These are temporary and usually subside within a week.
When carbohydrates are restricted, insulin levels drop and your kidneys begin excreting more sodium. This triggers a loss of electrolytes — particularly sodium, potassium and magnesium — leading to the classic flu-like symptoms.
Stay well hydrated, increase your salt intake, eat magnesium-rich foods and consider electrolyte supplements. Eating enough fat is also crucial — do not restrict calories too aggressively in the first week.
Once you are through the keto flu, you will want to fuel your body with great food. Browse our keto breakfast recipes and keto snack ideas to keep your energy up.