In reading Barry Groves' book yesterday "Natural Health & Weight Loss", I saw an item of interest in his chapter for diabetics:
"People who are overweight often go on to develop type-2 diabetes. For this reason, the accepted wisdom is that diabetes is caused by obesity. It isn't. Both obesity and diabetes are caused by the same thing: a low-fat, high-carb, 'healthy' diet. The only reason that diabetes appears to follow obesity is that obesity is more easily detected."
I know that not everyone who has diabetes is overweight, but the above description fits me to a T.