Headache on a keto diet is a natural reaction when your body switches from burning fat instead of sugar for energy. These symptoms start appearing after a few days of the ketogenic diet. Some of the reason that causes headache are:

• Low blood sugar level: Keto diet is a diet plan that reduces carbohydrates intake and replaces it with fats. Ketogenic diet transforms your metabolism and uses ketones as a default energy source instead of carbs. This may result in blood glucose level to drop, leading to headaches.

• Dehydration: When you’re in the transition state of keto, your body uses stored glucose called glycogen and excretes extra water when glycogen is used up.  Be sure to drink lots of water and add plenty of electrolytes, salts like potassium and magnesium to your diet. 

• Imbalance of electrolytes: Deficiency in nutrients and minerals can occur when carb intake decreases, electrolytes are increasingly excreted from the body through sweat and urine. The keto flu symptoms can be balanced by electrolytes such as sodium, potassium, and magnesium.

Headaches on a keto diet can be controlled by drinking enough water, eating foods having nutrients and through exercise. Make an effort to replenish those lost electrolytes by eating plenty of potassium and magnesium-rich foods.