ORIGINAL CONTRIBUTIONS Predictors of Preoperative Weight Loss in Morbidly Obese Adults Waiting for Bariatric Surgery: A Prospective Cohort Study Irmelin Bergh & Ingela Lundin Kvalem & Hilde Risstad & Linda D. Cameron & Falko F. Sniehotta # Springer Science+Business Media New York 2015 Abstract Background Preoperative weight loss is encouraged before bariatric surgery, as it is associated with improved surgical conditions. It has also been related to better postoperative outcomes, but this relationship is less clear. However, little is known about what predicts weight loss preoperatively, so the aim was to identify psychosocial and clinical predictors of preoperative weight loss. Methods Weight was measured at the first visit, the time of surgery approval, and on the day of surgery in 286 bariatric surgery patients (227 women). A questionnaire consisting of multiple psychosocial measures was completed before surgery. Results Preoperatively, patients experienced a mean weight loss of 3.8 %. Men lost significantly more weight than women (mean=5.4, SD=6.0 vs. mean=3.4, SD=5.8, t = -2.3, p <0.05), and 43.2 % of the patients lost ≥5% of their body weight. A high weight loss goal (β =0.20, p <0.001), frequent self-weighing (β =0.18, p <0.002), and being close to or at highest lifetime weight when applying for surgery (β = -0.30, p <0.0001) were identified as predictors of weight loss, after controlling for body mass index (BMI), gender, and length of preoperative time period. Conclusions A relatively low proportion of patients lost the recommended weight preoperatively. Our results indicate that patients benefit from monitoring weight preoperatively and that allowing patients to keep their high weight loss goals may contribute to higher weight loss. Further investigation of these predictors could provide valuable knowledge regard- ing how to support and motivate patients to lose weight preoperatively. Keywords Bariatric surgery . Preoperative weight loss . Morbidly obese . Psychosocial Introduction Bariatric surgery is an effective weight loss treatment option for obese individuals [1, 2]. Many programs require patients to lose weight before surgery [1]. Preoperative weight loss has been associated with improved surgical outcomes [3, 4] and greater postoperative weight loss [5–7], and may indicate the degree of patient motivation and likelihood of better compli- ance with postoperative recommendations [8–10]. Weight re- duction can reduce liver volume and visceral fat as well as improve the metabolic status of the patient [4, 11], which is the rationale stated in the American clinical guidelines [12] for encouraging preoperative weight loss. However, the relation- ship between preoperative weight loss and postoperative out- comes is less clear [ 7, 13]. There exists no consensus I. Bergh (*) : I. L. Kvalem Department of Psychology, University of Oslo, P.O. Box 1094 Blindern, N-0317 Oslo, Norway e-mail: Irmelin.bergh@psykologi.uio.no I. L. Kvalem e-mail: i.l.kvalem@psykologi.uio.no H. Risstad Centre of Morbid Obesity and Bariatric Surgery, Oslo University Hospital, Oslo, Norway e-mail: hiriss@outlook.com L. D. Cameron Psychological Sciences, University of California, Merced, 5200 North Lake Road, Merced, CA 95343, USA e-mail: Lcameron@ucmerced.edu F. F. Sniehotta Institute of Health & Society, Newcastle University, Newcastle NE2 4AX, UK e-mail: falko.sniehotta@newcastle.ac.uk OBES SURG DOI 10.1007/s11695-015-1569-y