How long does it take for the body to enter ketosis on a water fast?

It is not advisable to water fast for the purpose of entering ketosis, as it can be extremely dangerous to health and lead to electrolyte imbalance, dehydration, malnutrition and even death in some cases. Instead, a moderate calorie deficit combined with a low-carbohydrate diet is recommended for safe and sustainable ketosis induction. To enter ketosis you should reduce your daily carbohydrate intake to between 20 and 50 grams. Most people enter ketosis within 1 to 4 days, but it can take up to a few weeks for the full effects of the diet to kick in.