A 27-year-old woman is evaluated for overweight. Her weight has steadily increased over the past 10 years, and she has attempted weight loss through commercial diets and increased physical activity. Additionally, she has met with a dietician for nutritional guidance. She frequently eats fast food, and she snacks at work, before meals, and especially when she is under stress. She currently exercises 30 minutes daily. She does not smoke and rarely consumes alcohol. Medical history is otherwise unremarkable, and she takes no medications.
On physical examination, the patient is afebrile, blood pressure is 138/74 mm Hg, and pulse rate is 76/min. BMI is 29. Waist circumference is 92 cm (36 in). Head, neck, lung, and heart examinations are normal. The abdomen is obese without striae.
Laboratory studies, including fasting plasma glucose, total cholesterol, and thyroid-stimulating hormone levels, are normal.
In addition to calorie restriction and continued regular exercise, which of the following is the most appropriate next step to help this patient achieve sustained weight loss?