It usually takes three to four days for your body to go into ketosis because you have to use up your body's stores of glucose, i.e., sugar first, Keatley says. Any major diet change can give you some, uh, issues, and Keatley says he often sees patients who complain of IBS-like symptoms and feeling wiped out at the beginning of the diet. (The tiredness happens because you have less access to carbs, which give you quick energy, he explains.)
The ketogenic diet is not a benign, holistic, or natural treatment for epilepsy; as with any serious medical therapy, complications may result. These are generally less severe and less frequent than with anticonvulsant medication or surgery. Common but easily treatable short-term side effects include constipation, low-grade acidosis, and hypoglycaemia if an initial fast is undertaken. Raised levels of lipids in the blood affect up to 60% of children and cholesterol levels may increase by around 30%. This can be treated by changes to the fat content of the diet, such as from saturated fats towards polyunsaturated fats, and if persistent, by lowering the ketogenic ratio. Supplements are necessary to counter the dietary deficiency of many micronutrients.