Cathy is 56 years old and has just been diagnosed with type 2 diabetes. Her HbA1c is 68mmol/mol (8.4%). She is overweight with a BMI of 35.9 kg/m2. She leads quite a sedentary life in that she drives to and from work and sits at a desk all day. She eats in the works canteen, but cooks for herself and her family at night. She has four children age 14-26 and she helps look after her 2-year-old twin granddaughters. She has just been told her diagnosis. What does NICE suggest should be the first line treatment for her at this stage?