Karen is 35 years old and presents to the GP requesting referral for gastric band surgery as her friend had a successful operation. She admits to consuming a very high calorie diet but feels surgery is the best option as she has failed at a number of diets in the past. She states she normally gets hungry and after two weeks and struggles to control herself. This is followed by a period of binge eating as she feels low about herself. She is Caucasian, has no family history of heart disease or Diabetes and has never smoked. On examination she weighs 96kg and is 167cm tall (BMI 33.3). Her waist is 87cm.

According to NICE Guidelines, what is the next most appropriate course of action?