To prevent side effects such as the keto flu, begin transitioning your meal plan gradually. Start by understanding how many carbohydrates you take in most days. Then begin slowly reducing your carbohydrate intake over a period of a few weeks while gradually increasing your intake of dietary fat to keep your calories the same. You should also make sure to seek guidance from a professional to make sure this plan works best for you and your health goals. “See a dietitian and adapt the diet to fit your long-term needs,” Spano recommends.
When you’re eating the foods that get you there (more on that in a minute), your body can enter a state of ketosis in one to three days, she adds. During the diet, the majority of calories you consume come from fat, with a little protein and very little carbohydrates. Ketosis also happens if you eat a very low-calorie diet — think doctor-supervised, only when medically recommended diets of 600 to 800 total calories.