Over 80 percent of patients with Type II diabetes are obese.    Obesity by itself does not cause diabetes, as the overwhelming majority of people who suffer from obesity are not diabetic.  Obesity can, however, worsen blood sugar control by making the body less sensitive to insulin. 

It is unclear why people with diabetes have weight problems.  It is not simply because they eat too much.    There are numerous hormones that exist in the body that we are still learning about.   One hormone is Amylin.  Like insulin, Amylin is a  naturally occurring hormone that is secreted by the pancreas when we eat.  Amylin acts on the stomach and causes it to contract more slowly.  This in turn leads to a sense of fullness and weight loss, as well as improved sugars.  Amylin also decreases the secretion of glucagon, a hormone that raises sugar.