Over 400 million people around the world have been diagnosed with diabetes. Before the discovery of insulin, diabetes was treated through diet, from eating purely meat to the reliance on fats, and repeated fasting. After two centuries of conflicting medical advice, most authorities today believe that those with diabetes can have the same dietary freedom enjoyed by the rest of us, including the occasional ice-cream, leaving the job of controlling the disease to insulin therapy. However, this guiding principle has been accompanied by an explosive rise in diabetes over the last fifty years, and...