Rabbit starvation is a serious, though widely over-stressed, concern regarding lean-protein rich diets.
Rabbit starvation occurs when lean protein is consumed without additional calorie sources such as fat or carbohydrates. Protein is converted to usable calories by the liver, which can only convert about 800-1600 usable calories (200 - 400 protein grams) per day from protein. When these calories are insufficient, as they will be for most adults, ketosis begins. Ketosis is a process whereby the body burns fat for fuel, first dietary fat, then stored fat. When fat stores have been exhausted, the body will then turn to its own muscles and vital organs for fuel. Additionally, ammonia and urea are generated by the liver during the process, which are toxic at excessive levels.