The Expressive Writing in Bariatric Surgery

The aim of the present study is to test the efficacy of a psychological intervention focused on the expressive writing on the weight loss and adherence, 3 months after surgery in obese population undergoing to bariatric surgery. The sample will be divided into two groups: the expressive writing group that will perform the psychological intervention focused on expressive writing, and the control group that will not perform the psychological intervention. The assignment to the two groups will be randomized. The randomization will be carried out leaving each participant free to blindly choose one of the two sealed envelopes containing the writing instruction sheet and an empty sheet, respectively. All participants will complete psychometric questionnaires 3 days before surgery (T0) and 3 months (T1) after surgery in order to test the predicted variation on the chosen outcome in a very early stage after surgery. In order to assess the adherence level with a non self - report measure, the serum levels of 25(OH)D, B12, sideraemia and iron at T1 will be collected. Moreover, the adherence to follow up visits (surgical, nutritional and psychological) at 1 and 3 months will be assessed. The main hypothesis is that those patients undergoing expressive writing would have a greater early Excess Weight Loss % (EWL%), lower level of psychological impairment and higher level of adherence to treatment 3 months after surgery, compare to those patients who are not undergoing expressive writing.