Ketosis-prone diabetes has been an enigmatic entity ever since it was first described in 1955 by Hugh-Jones. In that series, it compromised 6% of diabetic Jamaicans and was typified by periodic insulinopenia, insulin resistance, lean body habitus, and no fatty liver. Since then, it has been described in many locales, especially in India and Africa, among minorities in the United States, and not necessarily in lean individuals. It has a variety of other names, including the following: J-type diabetes, Flatbush diabetes, atypical type 2 diabetes, phasic insulin-dependent diabetes, and type 3 diabetes. It most closely resembles type 1B diabetes in the WHO classification and is more commonly seen in nonwhite populations with marginal nutritional status or chronic malnutrition. Thus, it is possible that these individuals may have â-cell dysfunction due to either reduced glucose-stimulated insulin secretion or reduced â-cell mass from early life, similar to that seen in adult survivors of marasmus.