A 66-year-old man presents with blurred vision. He is 5 ft 10 in and weighs 214 lb (BMI 30.7); excess weight is mostly abdominal. The patient reports that since his last exam, he has been trying to eat in a more balanced way to lose 7% of his initial body weight, but this goal has been made more difficult due to recent onset of polyphagia; however, he does not know whether this increased hunger is the effect of a new brisk walking routine. Blood glucose level is 286 mg/dL; blood pressure is 129/80 mm Hg.