those with type 1 are result of auto immune problem and lack of insulin. so basically they can be either thin or fat. young type 2 tend to be obese (like myself previously) and older type 2 can be either thin or fat like my late mom and some of my friends. but usually they are above the age of 40's when diagnosed with type 2 diabetes.

initially they can be fat. fat do reduce the sensitivity to insulin, thus may result in diabetes mellitus type 2.

as the disease progress, with poor control of the disease by medication or in the absence of medication, the body uses more and more energy from non-glucose source, from fats primarily, resulting in weight loss. if the weight loss is severe enough, the patient becomes thin.

swollen legs have many reasons, may or may not have relation with diabetes.
common reasons of swollen legs could be pregnancy, heart failure, varicose disease, lymph stasis....