This situation is different from diabetes mellitus type 1. In this case, the islet cells, which make insulin in the pancreas, have been destroyed by the body, and as a result there is no insulin. Diabetes type 1 usually occurs in children or young adults, whilst diabetes type 2 usually occurs in older people. However, recently childhood obesity has led to some young adults and teenagers developing type 2 diabetes. Type 2 diabetes makes up around 90% of cases of diabetes, while type 1 diabetes and other types of diabetes make up the other 10%.