During a community health survey in urban Delhi, a 38-year-old woman is identified with newly diagnosed type 2 diabetes (fasting glucose 145 mg/dL, HbA1c 7.8%). She is overweight (BMI 28 kg/m²), sedentary, and reports a diet high in refined carbohydrates. She denies any symptoms. Physical examination shows no signs of diabetic complications. What is the most appropriate next step in management?