Working with collaborators as part of ongoing genetic studies, the investigators have identified several genetic variations (DNA changes) associated with the production of and processing of insulin and are trying to understand how these genetic variations cause differences in people's ability to produce or process insulin. Their findings will lead to an improved understanding of how the pancreas produces and processes insulin after a meal and will help to improve understanding of why some people develop diabetes and some people do not, despite similar levels of obesity. This question is of great public health significance because it is unlikely that the prevalence of obesity will fall dramatically in the foreseeable future.