A 42-year-old man from rural Maharashtra is screened at a health camp and found to have fasting blood glucose of 128 mg/dL and 2-hour post-glucose load value of 165 mg/dL. He is asymptomatic, with no prior diagnosis of diabetes. His BMI is 26 kg/m², and he has a family history of type 2 diabetes in his father. What is the most appropriate next step in management?