A 61-year-old woman who is 5 feet, 3 inches tall and weighs 125 pounds (57 kg) tells the nurse that she has a glass of wine two or three times a week. The patient works for the post office and has a 5-mile mail-delivery route. This is her first contact with the health care system in 20 years. Which of these topics will the nurse plan to include in patient teaching about cancer?