Especially in the beginning, you can experience what is known as ‘keto flu’ as your body adjusts to eating a lot fewer carbohydrates. You may experience headaches, muscle cramps, irritability, sugar cravings, and more. Always consult your doctor if you’re concerned, but there are a few things you can do to feel better: stay hydrated, avoid strenuous exercise, replace electrolytes (like potassium, magnesium, and sodium), get adequate sleep, and make sure you’re eating enough fat.