If a person does not consume the minimal daily requirement of carbohydrates than the body will start to use the fat and proteins in the body so that it can produce energy. The carbohydrates are the primary energy source in the body, so the lack of them makes the body low on energy, and also it makes it harder to think and to remain active. If this process continues for a prolonged period of time, than it causes the building up of ketones in the blood, which results in ketosis.
