obesity has become an increasingly important global health problem . currently , 13% of the world 's adult population aged 18 years and older are obese , with a body mass index ( bmi )  30  kg / m .
in 20082011 , 23% of the male and 24% of the female adult population in germany had a bmi  30  kg / m .
bariatric surgery is the most effective long - term treatment for the majority of morbidly obese patients with a bmi  40  kg / m or for those with a bmi  35  kg / m who are diagnosed with obesity - related medical comorbidities such as type 2 diabetes mellitus or arterial hypertension . in previous studies of weight loss outcomes after bariatric surgery , the amount of excess weight loss as a percentage ( % ewl ) was commonly used as a marker of weight loss success ( ewl  50% ) or weight loss failure ( ewl < 50% ) [ 4 , 5 ] .
% ewl is calculated using the following formula : ( postoperative weight loss)/(preoperative excess weight )  100 .
kg / m is recognized as the lowest limit of overweight , and therefore excess weight is calculated relative to a bmi of 25  kg / m [ 6 , 7 ] .
however , the dichotomous classification into success versus failure , with an arbitrarily defined cut - off at 50% ewl , does not reflect the considerably wide individual variation in postoperative weight loss that has been described in previous studies [ 8 , 9 ] .
approximately 15% to 20% of all bariatric surgery patients fail to achieve adequate % ewl [ 10 , 11 ] ; inadequate weight loss is considered to be ewl < 25% according to the reinhold criteria .
surprisingly little is known about the factors that promote or hinder weight loss after bariatric surgery .
given the background of a multifactorial etiology of obesity , a multidisciplinary evaluation before bariatric surgery is recommended , and the assessment of psychosocial factors in addition to the medical examination has become highly relevant [ 13 , 14 ] . however , although the number of bariatric procedures performed is rising [ 15 , 16 ] , conclusive empirical evidence about the impact of psychosocial factors on postoperative weight loss outcomes is still lacking . psychological factors and mental disorders have been associated with weight loss results after bariatric surgery .
notably , up to 70% of obese patients considering bariatric surgery present with high rates of mental comorbidities , with depression , anxiety , and eating disorders being the most prevalent [ 17 , 18 ] . within the current medical - theoretical framework , causal pathways between obesity and mental disorders are likely to be bidirectional .
on one hand , being a target of weight - based discrimination and stigmatization might lead to depressive symptoms with feelings of worthlessness , social anxiety , and isolation , especially in extremely obese patients [ 19 , 20 ] . on the other hand
, depression and anxiety disorders might contribute to weight gain by interfering with healthy eating behaviors and might complicate weight loss . eating in response to negative emotions might have an anxiolytic effect , and an increased appetite extending to overeating can be a symptom of depression . furthermore , stress might play an important intermediating role in the association between obesity and mental disorders : under conditions of chronic stress , the activity of the hypothalamic - pituitary - adrenal axis , which responds to stress by releasing cortisol and hormones that modulate sympathetic nervous system activity , becomes dysregulated , a state that has been implicated in depression and anxiety disorders as well as in obesity .
obese patients with comorbid mental disorders might have difficulties in adhering to the behavioral changes required to benefit from bariatric surgery .
however , the predictive value of preoperative depression and anxiety disorder for weight loss outcomes after bariatric surgery is controversial ; different studies have shown a negative influence , a positive influence , or no effect .
additionally , there is evidence that the severity rather than the types of mental disorders appears to be more relevant for weight loss outcomes ; that is , a greater overall psychological burden is associated with less weight loss after bariatric surgery [ 27 , 28 ] . coping strategies , used when confronting difficult situations in daily life , and the motivation to undergo surgery might also be related to different weight loss outcomes ; however , research is scarce .
recent studies have reported more avoidant and ( delegated ) active coping in patients seeking bariatric surgery versus patients seeking conservative treatment options   or more avoidance and depressive coping reactions in a subgroup of emotional dysregulated / undercontrolled versus resilient / high - functioning prebariatric women .
although maladaptive coping behavior might complicate postbariatric weight loss , clear associations have not been established yet . to date , most research on the role of prebariatric psychological variables in treatment success has focused on gastric bypass surgery .
laparoscopic sleeve gastrectomy ( lsg ) as a restrictive single - stage procedure is relatively new in the field of bariatric surgery but has already proven its efficacy in weight reduction with low surgical risks . to our knowledge ,
no studies have systematically assessed the relationship between postoperative % ewl and preoperative psychological burden ( as a broader construct comprising  perceived stress ,   depression ,  
anxiety ,  and  mental impairment  ) , coping style , and the motivation to undergo surgery in a clinical sample of lsg patients .
hence , assessing a broad range of preoperative patient characteristics might be useful to identify homogeneous subgroups of lsg patients with different needs to tailor interventions and optimize postoperative weight loss outcomes and well - being .
therefore , the main aim of the present study was to characterize patients with low , moderate , and high postoperative % ewl retrospectively using between - group comparisons to examine whether lsg patients with different % ewl levels after surgery differed preoperatively in ( 1 ) their psychological burden in terms of the levels of  perceived stress ,   depression ,  
anxiety ,  and  mental impairment ,  ( 2 ) coping style ( e.g. ,  active coping  ) , and ( 3 ) their motivation to lose weight . as a secondary aim , we wanted to study whether the % ewl groups differed on a range of preoperative patient characteristics , such as ( a ) weight and bmi , ( b ) sociodemographic status , ( c ) clinically diagnosed comorbidities including eating disorders , and ( d ) the use of psychotherapy . to do so
, lsg patients were evaluated approximately 12 months before surgery and on average 20 months after surgery .
as part of the presurgical psychosomatic evaluation for bariatric intervention at the multidisciplinary obesity center of the university hospital charit - universittsmedizin berlin in germany , patients who planned to undergo bariatric surgery were assessed by an experienced clinical psychologist or physician specialized in psychosomatic medicine .
a semistructured interview was performed for the psychosocial assessment and diagnosis of mental disorders including eating disorders according to the international classification of diseases ( icd-10 ) .
additionally , tablet pcs were used to obtain psychometric measurements of psychological variables ( i.e. , the severity of  perceived stress ,   depression ,   anxiety ,  and  mental impairment  as well as  coping style  and  motivation to lose weight  ) by employing well - established standard questionnaires . in accordance with the german guidelines for obesity surgery [ 14 , 33 ] ,
bariatric surgery was not offered to patients with mental retardation or severe untreated psychiatric disorders such as schizophrenia , emotionally unstable personality disorder , alcohol or drug abuse / dependence , and suicidality .
further medical consultations involved a surgeon and an endocrinologist . between april 2009 and august 2012 , a medical database was used to identify 96 bariatric surgery patients who underwent lsg and fully completed the presurgical psychometric assessment , and they were contacted for follow - up . from that sample , 71% ( n = 68 ) of the patients participated in the follow - up , and 29% ( n = 28 ) of them declined participation or could not be reached . for the present study
, we excluded patients with less than 1 year of follow - up after lsg surgery ( n = 4 ) . moreover , bariatric surgery patients who underwent gastric banding or roux - en - y gastric bypass surgery were not included in our study because we sought to assess a homogeneous sample and to eliminate the effect of type of surgical procedure on % ewl ( due to the significantly inferior / superior weight loss achievable by these procedures ) . the present cohort consisted of 64 morbidly obese patients ( 46 women and 18 men ) who had undergone lsg .
the average points of assessment were 12 months prior to surgery and 20 months after surgery .
data collected preoperatively included sociodemographic information , clinically diagnosed comorbidities ( metabolic syndrome , mental disorders including eating disorders such as binge eating disorder , night eating syndrome , and sweet eating syndrome , or disordered eating behaviors such as hyperphagia , which describes a subsyndromal excessive eating behavior and/or an increased high - calorie food intake similar to terms such as emotional overeating and grazing without reaching the criteria for binge eating disorder ) , and the use of past or current psychotherapy . for the psychometric assessment of psychological variables , the following validated ( with the exception of the  motivation to lose weight  survey ) self - rating questionnaires were employed via tablet pcs . 

stress was assessed using the perceived stress questionnaire ( psq )   in its revised german 20-item version ( psq-20 ) .
the instrument assesses subjectively experienced stress reactions ( worries , tension , and joy ) and the perception of nonspecific external stressors ( demands ) .
an overall index score is calculated from all items with values between 0 and 1 ; higher scores indicate higher levels of perceived stress .
the internal consistency of the psq-20 total score was indicated by cronbach 's  = 0.94 . 

depression was assessed using the german version of the patient health questionnaire depression scale ( phq-9 ) [ 37 , 38 ] .
phq-9 is a 9-item screening instrument for the diagnosis of major depression and the assessment of depressive symptom severity .
the internal consistency was represented by cronbach 's  = 0.87 , and the level of agreement between the clinical diagnosis of depression according to icd-10 and the phq-9 score ( cut - off  10 ) was moderate ( cohen 's k = 0.45 ) ; specificity was 84% , and sensitivity was 64% . 

anxiety was assessed using the german version of the generalized anxiety disorder 7-item ( gad-7 ) scale [ 39 , 40 ] .
gad-7 is a brief screening instrument for the diagnosis of generalized anxiety disorder and the assessment of symptom severity .
the total score ranges from 0 to 21 , and the cut - off score is 10 .
scores range from 0 to 3 , with higher scores indicating higher levels of mental impairment .
the internal consistency of the isr total score was indicated by cronbach 's  = 0.92 . 

coping style was assessed using the german version of the brief cope questionnaire [ 42 , 43 ] .
patients were asked to think of their usual thoughts and actions when facing a difficult situation .
the brief cope consists of 28 items that assess four coping styles :  avoidant coping 
( i.e. , self - blame , denial , and venting ) ,  seeking support 
( i.e. , the use of instrumental support , emotional support , and religion ) ,  positive reframing 
( i.e. , acceptance , positive reframing , and humor ) , and  active coping 
scores range from 1 to 4 , with higher scores indicating higher levels of coping on each scale .
a motivation survey was developed with 10 items asking how strongly patients were  self - motivated  to lose weight or motivated by their  social environment 
( i.e. , partner , family / children , friends , colleagues , and employer ) or  treatment environment 
patients indicated their answers on a 5-point scale that ranged from 1 = not at all to 5 = very strong .
body weight ( kg ) , height ( cm ) , and bmi ( kg / m ) were extracted from the medical database . on average , 20 months after surgery
, weight status was either extracted from the medical database or self - reported , and weight loss was assessed . as a standard for evaluation ,
weight change is reported as the percentage of excess weight loss ( % ewl ) , which is calculated using the following formula : ( postoperative weight loss)/(preoperative excess weight at time of surgery )  100 .
kg / m is recognized as the lowest limit of overweight , and therefore excess weight is calculated in relation to a bmi of 25  kg / m [ 6 , 7 ] .
all analyses were conducted using spss version 22 ( ibm , armonk , ny ) , and the alpha level of statistical significance was set at p < 0.05 .
patients were classified into three groups of nearly equal size according to the observed postoperative % ewl distribution of the sample based on tertiles .
one - way between - groups multivariate anovas were performed to compare patients with low , moderate , and high % ewl (= independent variable ) with respect to group differences in preoperative ( 1 ) psychological burden , ( 2 ) coping style , and ( 3 ) motivation to lose weight (= dependent variables ) .
( psq-20 ) ,  depression  ( phq-9 ) ,  anxiety  ( gad-7 ) , and  mental impairment  ( isr ) ( r = 0.780.89 ) , and strong loadings ( > 0.90 ) of each of these variables on a single factor explained 87% of the total variance in the data set .
 motivation to lose weight ,  the broader construct  psychological burden  was generated and used for further multivariate analyses to retain statistical power .
for the combined dependent variable  psychological burden ,  four variables were used :  perceived stress  ( psq-20 ) ,  depression  ( phq-9 ) ,  anxiety  ( gad-7 ) , and  mental impairment  ( isr ) . for the combined dependent variable  coping style ,  four variables of brief cope were used :  avoidant coping , 
for the combined dependent variable  motivation to lose weight ,  three variables were used :  self - motivation ,   social environment ,  and  treatment environment .  for additional exploratory analyses , univariate anovas were performed with bonferroni - adjusted post hoc comparisons using tukey 's hsd test to control for type i error .
chi - square tests were conducted for the nominal dependent variables , with post hoc comparisons using standardized residuals and a critical value of 1.96 indicating significant group differences .
the magnitude of group differences was further analyzed by means of effect sizes ; for metrical data , we used cohen 's d ( 0.2 = small , 0.5 = moderate , and 0.8 = large ) , and for nominal data , we used cohen 's w ( 0.1 = small , 0.3 = moderate , and 0.5 = large ) .
preliminary analyses included describing the variables , screening for missing values and outliers , and testing for the normality , linearity , homogeneity of variance / variance - covariance matrices , and multicollinearity of the dependent variables , with no serious violations noted .
the mean postoperative % ewl was 53% ( sd = 24% , range : 14115% ) . in relation to the observed % ewl distribution in our study ,
patients were classified into three % ewl groups of nearly equal size based on tertiles : low ( n = 21 , ewl range : 1439% ) , moderate ( n = 22 , ewl range : 4059% ) , and high ( n = 21 , ewl range : 60115% ) .
postoperative % ewl differed significantly between the three % ewl groups ( p < 0.001 ) .
the results showed no significant group difference in the follow - up time interval ( p > 0.05 ) ( table 1 ) .
weight and bmi characteristics for the low-%ewl , moderate-%ewl , and high-%ewl groups before and after bariatric surgery are presented in table 1 . within all three % ewl groups , the patients ' mean weight , excess weight , and bmi decreased significantly after surgery ( p < 0.001 ) .
significant preoperative group differences between patients of moderate and high % ewl were detected : patients with high % ewl had a lower preoperative weight ( p = 0.018 ) , excess weight ( p = 0.012 ) , and bmi ( p = 0.015 ) .
preoperative weight and bmi differences between the low-%ewl and moderate-%ewl groups and between the low-%ewl and high-%ewl groups did not reach statistical significance ( p > 0.05 ) . in the high-%ewl group ,
38% ( n = 8) of the patients attained a postoperative nonobese bmi of < 30  kg / m .
preoperative sociodemographic characteristics for the groups with low , moderate , and high % ewl are presented in table 2 . among the three % ewl groups
, there were no significant differences in age , sex , partnership , or employment status before surgery ( p > 0.05 ) .
a small but statistically significant group difference in education levels was found : on average , the high-%ewl group had 2.2 more years of education than the low-%ewl group ( p = 0.010 ) .
there were no statistically significant differences in education levels between the low-%ewl and moderate-%ewl groups or between the moderate-%ewl and high-%ewl groups ( p > 0.05 ) .
with regard to physical comorbidities , table 2 shows that all three % ewl groups had high rates of presurgically diagnosed metabolic syndrome symptoms ; approximately half of the patients in each group suffered from type 2 diabetes mellitus .
no group differences in diabetes prevalence were found ( p > 0.05 ) . with regard to mental comorbidities ,
the groups with low and high % ewl presented with particularly high rates of presurgically diagnosed mental disorders ( i.e. , depression ) ; however , the results showed no statistically significant group differences in the prevalence of mental disorders ( p > 0.05 ) ( table 2 ) .
all three % ewl groups presented with high rates of disordered eating behaviors such as hyperphagia .
group differences in the prevalence of eating disorders such as binge eating disorder , night eating syndrome , or sweet eating syndrome could not be detected ( p > 0.05 ) ( table 2 ) .
altogether , a total of 39% ( n = 25 ) of the patients reported past or current psychotherapeutic treatment .
the results showed a statistically significant group difference in the use of psychotherapy : slightly more patients in the low-%ewl group underwent psychotherapeutic treatment before lsg surgery compared with those in the moderate-%ewl group ( p = 0.013 ) . for the high-%ewl group , no statistically significant difference in the use of psychotherapy could be identified ( p > 0.05 ) ( table 2 ) .
preoperative psychological characteristics for the groups with low , moderate , and high % ewl are presented in table 2 .
the results revealed no statistically significant difference between the three % ewl groups in the overall preoperative psychological burden in terms of  perceived stress 
( psq-20 ) ,  depression  ( phq-9 ) ,  anxiety  ( gad-7 ) , and  mental impairment  ( isr ) ( f(8,118 ) = 0.9 , p = 0.535 ; pillai 's trace = 0.1 ; d = 0.5 ) .
furthermore , the three % ewl groups showed no statistically significant difference in their overall preoperative motivation to lose weight in terms of  self - motivation  or motivation from the  social environment  or  treatment environment  ( f(6,118 ) = 1.0 , p = 0.428 ; pillai 's trace = 0.1 ; d = 0.4 ) . in terms of the overall preoperative coping style ( brief cope
) , the three % ewl groups showed no statistically significant difference ( f(8,118 ) = 1.6 , p = 0.145 ; pillai 's trace = 0.2 ; d = 0.7 ) . to further investigate our main research question ( 2 ) ,
when the results for the different coping styles (  avoidant coping ,   seeking support ,   positive reframing ,  and  active coping  ) were considered separately in bonferroni - adjusted comparisons , a marked difference could be identified : patients with high postoperative % ewl reported slightly but significantly higher scores for  active coping  behavior prior to surgery compared with patients with low % ewl ( p = 0.019 ) and moderate % ewl ( p = 0.022 ) .
the low-%ewl and moderate-%ewl groups did not differ in this regard ( p > 0.05 ) ( table 2 and figure 1 ) .
the positive relationship between preoperative  active coping  and postoperative % ewl was confirmed by a statistically significant correlation analysis ( r = 0.36 ; p = 0.004 ) .
the results showed no statistically significant differences between patients who dropped out of the study ( n = 28 ) and patients who were reassessed after lsg ( n = 64 ) in preoperative variables such as age , sex , bmi , years of education , prevalence of metabolic syndrome symptoms , mental disorders including eating disorders , or psychotherapy use ( p > 0.05 ) .
furthermore , the two groups showed no statistically significant differences in their overall preoperative psychological burden ( f(4,87 ) = 1.9 , p > 0.05 ; pillai 's trace = 0.08 ; d = 0.6 ) , coping style ( f(4,87 ) = 1.0 , p > 0.05 ; pillai 's trace = 0.04 ; d = 0.4 ) , or motivation to lose weight ( f(3,87 ) = 2.1 , p > 0.05 ; pillai 's trace = 0.07 ; d = 0.5 ) ( data not shown ) .
in the present study , we employed a retrospective approach to examine associations between preoperative factors and the amount of % ewl achieved on average 20 months after bariatric surgery in 64 patients who underwent lsg . patients were classified into groups with low , moderate , and high postoperative % ewl based on tertiles to identify homogeneous subgroups of lsg patients for group comparisons .
our results showed that lsg patients with high % ewl had a lower weight and bmi prior to surgery compared with patients with moderate % ewl , but no significant weight and bmi differences compared with patients with low % ewl were found .
this initially counterintuitive finding is in line with previous studies of gastric bypass surgery reporting that patients who were preoperatively less obese have a higher postoperative % ewl [ 9 , 44 , 45 ] .
one possible explanation is that patients who were preoperatively more obese ( i.e. , bmi  50  kg / m ) tend to stagnate earlier in their weight loss process and begin to regain weight as early as 12 months after surgery .
although early weight stagnation and weight regain might play a role , our prepost study design masks the time course of weight change , and therefore explanations remain speculative at this point .
longitudinal data are necessary to assess the course of weight after lsg in more detail . the preoperative psychological burden and motivation to lose weight were not associated with the amount of % ewl in patients following lsg intervention . however , more self - reported  active coping  behavior ( assessed by the following items :  i have been concentrating my efforts on doing something about the situation i am in  ;  i have been taking action to try to make the situation better  ;  i have been trying to come up with a strategy about what to do  ; and  i have been thinking hard about what steps to take  ) seemed to be beneficial for treatment success in terms of more favorable weight loss outcomes . in summary ,
a more  active coping  style might be predictive of higher postoperative weight loss outcomes .
however , the results provided no clear evidence of a clinically important role of preoperative mental health and the motivation to lose weight in the weight - related treatment success of lsg .
previous studies have identified psychological predictors of weight loss outcomes after bariatric surgery ; for example , some have observed less weight loss in patients with mood and anxiety disorders [ 24 , 27 ] .
however , across reviews of the prebariatric predictors of postbariatric weight loss [ 28 , 46 ] , relationships between psychological factors and weight - related surgery outcomes seem inconsistent and appear to vary by study design and sample .
bariatric surgery patients must meet certain criteria to be eligible for surgery ( e.g. , they must meet a certain bmi requirement , be free of potential contraindications , and obtain approval from health care team members ) , which evidently results in a homogenized sample of medically and mentally healthier patients .
therefore , the variability within our sample of patients who underwent lsg surgery might be reduced , which could in turn lower the magnitude of % ewl group differences and underestimate the impact of psychological factors on weight loss outcomes . on the other hand , static factors such as sociodemographic status assessed prior to bariatric intervention might have limited practical value for predicting weight loss because they do not capture patients ' flexibility in adapting to changing circumstances after the intervention .
in fact , some studies suggest that postbariatric factors such as the ( re)occurrence of depressive and anxiety disorders [ 27 , 48 ] or the loss of control over eating   have a much stronger impact on weight loss outcomes after bariatric surgery than prebariatric factors do
while suggesting tailored interventions to optimize treatment success , our results demonstrate the difficulty of preoperatively identifying patients who are at risk for more unfavorable postoperative weight - related outcomes .
however , our results might also indicate that more active coping behavior is a marker of higher postoperative weight loss . as discussed by ahnis et al .
, active coping behavior in obese patients seeking a bariatric intervention might include the preoperative search for information about surgical treatment options on the internet , in support groups , in informative meetings , or during medical visits and examinations .
this behavior may in turn contribute to patients developing a more informed and educated perspective on the possibilities and limitations of lsg surgery and the necessary lifestyle modifications ( e.g. , following dietary advice and physical activity recommendations ) to achieve higher and sustained weight loss after surgery .
however , because bariatric surgery leads to a profound change in patients ' gastrointestinal and whole - body physiology , it is important to also consider potential physiological mechanisms .
in fact , such considerations might be complex , and psychological and physiological factors might actually combine and interact in influencing outcomes .
the strength of our study is that it was conducted in a naturalistic clinical setting .
in addition , whereas the majority of previous research in this area focused on roux - en - y gastric bypass surgery , we had access to a homogeneous clinical sample of patients undergoing lsg .
to the best of our knowledge , this was the first study that systematically assessed the relationship between postoperative % ewl on average 20 months after surgery and the preoperative psychological burden ( as a broader construct comprising  perceived stress ,   depression ,  
anxiety ,  and  mental impairment  ) , coping style , and motivation to undergo surgery in a sample of lsg patients .
the size of our sample was comparable to that of other small - scale studies in the field of bariatric surgery .
moreover , the attrition rate in our study was rather small , and our attrition analyses showed no significant differences in preoperative variables between patients who provided data at follow - up compared with those who did not .
however , from a statistical perspective , the sample size is still small , allowing for only a few statistical tests in addition to a large set of exploratory analyses .
the patients ' postoperative weight was self - reported , which might undermine the validity of the % ewl classification scheme . however , self - reporting of weight is relatively common in obesity studies , and there is evidence that objectively measured and self - reported weights are not significantly different in bariatric surgery patients .
finally , it can be argued that the generation of  psychological burden  as a broader construct comprising  perceived stress ,   depression ,  
however , all these variables proved to be strong determinants of patients ' psychological burden , with high intercorrelations and high loadings on a single factor , thus supporting the use of the combined variable to capture the construct of psychological burden .
although an  active coping  style seemed to be of value in predicting more favorable postoperative weight loss outcomes , neither biomedical markers nor an extensive set of other psychological constructs assessed before surgery enabled a clinically relevant prediction of the weight - related treatment success of lsg . our study highlights the need for further research on the psychological correlates of postbariatric health outcomes . nevertheless , despite our finding of a considerably large degree of variation in postoperative weight loss in our sample of lsg patients , all three % ewl groups showed significant weight loss and decreases in body weight and bmi , including the low-%ewl group .
therefore , the bariatric intervention proved to be highly beneficial for the vast majority of patients , thus promoting positive health outcomes .
 
 background . the amount of excess weight loss ( % ewl ) among obese patients after bariatric surgery varies greatly . 
 however , reliable predictors have not been established yet . 
 the present study evaluated the preoperative psychological burden , coping style , and motivation to lose weight as factors determining postoperative treatment success . 
 methods . the sample included 64 morbidly obese patients with a preoperative bmi of 51  8  kg / m2 who had undergone laparoscopic sleeve gastrectomy ( lsg ) . 
 well - established questionnaires were applied before surgery to assess the psychological burden in terms of  perceived stress  ( psq-20 ) ,  depression  ( phq-9 ) ,  anxiety  
 ( gad-7 ) , and  mental impairment  ( isr ) as well as coping style ( brief cope ) and motivation to lose weight . 
 % ewl as an indicator for treatment success was assessed on average 20 months after surgery . 
 results . based on the % ewl distribution 
 , patients were classified into three % ewl groups : low ( 1439% ) , moderate ( 4059% ) , and high ( 60115% ) . 
 lsg patients with high % ewl reported significantly more  active coping  behavior prior to surgery than patients with moderate and low % ewl . 
 patients ' preoperative psychological burden and motivation to lose weight were not associated with % ewl . 
 conclusion . 
 an  active coping  style might be of predictive value for better weight loss outcomes in patients following lsg intervention . 
1. Introduction
2. Subjects, Materials, and Methods
3. Results
4. Discussion
5. Conclusion