The Keto Diet Is Gaining Popularity, but Is It Safe? The “keto” diet is any extremely low- or no-carbohydrate diet that forces the body into a state of ketosis. Ketosis occurs when people eat a low- or no-carb diet and molecules called ketones build up in their bloodstream. Low carbohydrate levels cause blood sugar levels to drop and the body begins breaking down fat to use as energy. 1. Ketosis is actually a mild form of ketoacidosis. Ketoacidosis mostly affects people with type 1 diabetes. In fact, it is the leading cause of death of people with diabetes who are under 24 years of age. 2. Once your body enters ketosis, you also begin to lose muscle, become extremely fatigued, and eventually enter starvation mode. Then it actually becomes even harder to lose weight. 3. Keto diets should only be used under clinical supervision and only for brief periods.