Why do people with diabetes type 1 tend to be fat?

Not true: Most type 1 diabetics are not obese. The underlying problem is that their pancreas cannot make enough insulin. Type 2 diabetics are typically obese. The obesity is associated with Insulin resistance. The pancreas is making insulin, but the Insulin does not work correctly. Ultimately, the pancreas starts to fail and can't make enough Insulin to compensate for the Insulin resistance.