A 30-year-old G3P2 obese woman at 26 weeks' gestation with no significant past medical history states that diabetes runs in her family. Her other pregnancies were uncomplicated. The results of a 3-hour glucose tolerance test show the following glucose levels:* 0 (fasting): 90 mg/dL 1 hour: 195 mg/dL* 2 hours: 155 mg/dL 3 hours: 145 mg/dLAs a result, she is diagnosed with gestational diabetes. She is counselled to start diet modification and exercise to control her glycemic levels. 3 weeks after her diagnosis, she presents her values:* Fasting: 95 mg/dL 1 hr pp: 185 mg/dLWhat is the best management?