According to Encyclopedia Britannica, there are no known diseases caused by carbohydrate deficiency. The human body has no dietary requirement for carbohydrates. If fewer than 50 to 100 grams of carbohydrates are consumed daily, the body begins to convert protein and fat into glucose, a process called ketosis.
During ketosis a person may have bad breath and feel nauseated, says WebMD. However, Ketogenic Diet Resource reports that many individuals may deliberately induce ketosis by dietary carbohydrate restriction in order to experience health benefits such as remission of diabetes, reversal of heart disease, treatment of epilepsy and relief for aching joints.