Were they type 1?  Almost every person with type 1 diabetes is thin.  For those individuals, their body stops producing insulin, something entirely beyond their control no matter what they do. However, type 2 diabetics are almost always grossly overweight.  Their bodies produce tons of insulin, but the cells can't use it correctly because they've destroyed their bodies from years of abuse.  They only use insulin because their body will still have some minimal response to it, so if they flood the system it will partially work.  However, skeletal muscle doesn't require insulin to pull sugar from the bloodstream, meaning that if these fat bastards would exercise (never going to happen) that they could actually control the problem on their own, or at least partially. I know you probably know this information forwards, backwards and sideways.  I just wanted to list it so that the lurking fatties can see yet again that their health problems are 100% their fault.