A 25-year-old male with a first episode of psychosis is started on olanzapine 10 mg nightly. At his 12-week follow-up, he has gained 15 pounds. His fasting glucose is 118 mg/dL and triglycerides are 220 mg/dL. According to ADA/APA metabolic monitoring guidelines for second-generation antipsychotics, which of the following is the most appropriate next step?