BACKGROUND Currently, bariatric surgery is the most effective treatment for severe obesity and its metabolic complications; however, 15-35% of the patients that undergo bariatric surgery do not reach their goal for weight loss. The aim of this study was to determine the proportion of patients that didn't reach the goal of an excess weight loss of 50% or more during the first 12 months and determine the factors associated to this failure. METHODS We obtained the demographic, anthropometric and biochemical information from 130 patients with severe obesity who underwent bariatric surgery in our institution between 2012 and 2017. We used self-reports of physical activity, caloric intake and diet composition. An unsuccessful weight loss was considered when the patient lost < 50% or more of the excess weight 12 months after surgery. We compared the characteristics between the successful and unsuccessful groups in order to find the factors associated with success. RESULTS We included 130 patients (mean age 48 ± 9 years, 81.5% were women). One year after surgery, 26 (20%) had loss < 50% EBW. Unsuccessful surgery was associated with an older age, previous history of hypertension, abdominal surgery or depression/anxiety, also the number of comorbidities and unemployment affected the results. These patients loss enough weight to improve some of their comorbidities, but they are more prone to regain weight 2 years after surgery. CONCLUSIONS A fifth of the patients undergoing bariatric surgery may not lose enough weight to be considered successful by current standards. Some patients may benefit from the surgery in the short term, but they are more likely to regain weight after 2 years. The factors influencing this result are still controversial but may be population-specific. Early detection of the patients that are more likely to fail is imperative to establish additional therapeutic strategies, without denying them the opportunity of surgery or waiting for weight re-gain to occur.

中文翻译：

---

减肥手术后成功减肥真的有任何预测因素吗？

背景技术目前，减肥手术是治疗严重肥胖及其代谢并发症的最有效方法。然而，进行减肥手术的患者中有15％至35％未能达到减肥目标。这项研究的目的是确定在最初的12个月内未达到体重减轻50％或更多的目标的患者比例，并确定与该失败相关的因素。方法我们从2012年至2017年间从我院进行减肥手术的130名严重肥胖患者中获得了人口统计学，人体测量学和生化信息。我们使用了体育锻炼，热量摄入和饮食组成的自我报告。当患者术后12个月减掉的体重<50％或更多，则认为体重减轻失败。我们比较了成功和不成功群体之间的特征，以便找到与成功相关的因素。结果我们纳入了130名患者（平均年龄48±9岁，女性占81.5％）。手术一年后，有26名（20％）的EBW损失小于50％。手术失败与年龄增长，高血压史，腹部手术或抑郁/焦虑症有关，合并症的数量和失业影响了结果。这些患者减轻了体重，可以改善一些合并症，但术后2年他们更容易恢复体重。结论接受减肥手术的患者中，有五分之一的体重可能没有减轻到目前的标准所认为不能成功。某些患者可能会在短期内从手术中受益，但两年后他们更有可能恢复体重。影响该结果的因素仍存在争议，但可能因人群而异。必须尽早发现更有可能失败的患者，以确立其他治疗策略，而又不能否认他们有手术机会或等待体重增加的机会。