Psychological Indications, Contraindications, And Follow-up To Bariatric Surgery

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Author(s):

	Elisabeth Ardelt-Gattinger
	Department of Psychology, Paris Lodron University, Salzburg, Austria Obesity Academy Austria
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	Erich Gattinger
	Department of Psychology, Paris Lodron University, Salzburg, Austria; Obesity Academy Austria
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	Susanne Ring-Dimitriou
	Obesity Academy Austria Department of Sports Science and Kinesiology, Paris Lodron University, Salzburg, Austria
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	Daniel Weghuber
	Assoc. Professor (Priv. Doz.) of Pediatrics Department of Pediatrics
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 Bariatric surgery for adolescents

Children and adolescents today show “the same aversion to overweight children and adolescents” as was found in a 1961 study (1). Adolescents are especially at risk for forming these negative opinions during puberty. During this time, high emotional instability leads to vulnerability in personal, sexual, and social development (2, 3). Various studies indicate that mental disorders such as phobias and depressions are more likely to be the result of obesity rather than the cause, but a bidirectional association has also been demonstrated (4, 5). Caregivers worry about the fact that the instability of puberty itself may lead to wrong decisions about the type of surgical intervention and to inadequate evaluation of the post-operative, long-term consequences of bariatric interventions.

In this chapter we present a review of the literature followed by the results of studies we performed in order to improve the evaluation, care and follow-up of obese adolescents searching for bariatric surgery. 

Pre-surgical evaluation

Because bariatric surgery has not been fully accepted as treatment for obesity among adolescents, most studies to date include adult subjects. In contrast to patients evaluated for other life-prolonging and health-ensuring surgical measures, bariatric surgery candidates are subjected to psychological or psychiatric evaluation to determine surgical eligibility (6).

Obesity is recognized as an illness that makes obese people unable to attain long-term weight control using traditional methods due to numerous reasons (7). Nevertheless, obese people are targeted for “assessment of psychopathology and personality examination” by psychosomatic specialists (8). Even recently published work points to hypochondria, anxiety, intelligence level, depression, and obsessive-compulsive disorder as contributing factors for obese adults and teenagers (9).

Preferred assessment instruments include the Minnesota Multiphasic Personality Inventory or the Minnesota Clinical Multiaxial Inventory (MMPI, MCMI) and the Personality Assessment Inventory (PAI) (8-11). Despite extensive testing conducted since the 1960s by Stunkard & Wadden (12), Latner & Stunkard (13) and Pudel & Westenhöfer (14) to develop questionnaires identifying specific eating behaviors, the personality instruments remain in widespread use. To date, empiric evidence is lacking to support the need for a special preoperative psychopathology assessment for obese patients (15,16). Instead, accumulated evidence suggests that these evaluations are “simply insufficient” to predict surgical success, sufficient weight-loss, improved comorbidities, or improved quality of life (17-20).

Testing protocols have been supplemented by clinical interviews that provide ambiguous responses. For instance, clinical interviewers are charged with assessing patients for “factors potentially (sic) disturbing the effectiveness” (21) of surgery that “might (sic) influence post-OP weight loss” (22). Moreover, popular psychoanalytical questions refer to the “psychological firewall, which the fat offers” (23). The Boston Interview for Gastric Bypass, whose criteria are highly disputable, has been implemented for pre-operative assessment (24).

Moreover, scientific investigations show that a desire to get approval for surgery leads to false answers during the clinical interview. In a study of second inquiry, after a psychologist had granted patients “clearance” for surgery, the severity of depressions rose significantly (25).

In summary, Walfish et al. (26) asserted that pre-surgical instruments and examination practices vary widely between psychologists. The published literature is often contradictory and “far from conclusive” regarding predictors of bariatric post-operative success (27). Some authors have strongly advised that studies regarding “variability in clinical decision making” be performed (28).

The inconsistency in evaluation methods notwithstanding, psychological factors during the radical change in lifestyle accompanying bariatric surgery should not be dismissed. Although post-operative measures are more relevant to post-surgical therapy, a pre-operative visit is necessary to evaluate the patient for pre-operative testing and decide on the most appropriate surgical method.

Mental disorders strongly associated with obesity that manifest with symptoms of disturbed eating behavior should also be investigated. Binge eating disorder is prevalent in 30% of adults and 24% of teenagers, whereas bulimia is prevalent in 7% of adults and 6% of teenagers in a representative Austrian sample of 540 obese teenagers and 1200 obese adults. Including the detection of pre-clinical eating disorders (pre-occupation with weight and shape as well as pre-clinical bulimia), which were prevalent in 30% of teenagers of the same sample, is especially important (17).

Instruments used to evaluate pre-surgical psychological disorders and phobias relevant to pediatric obesity, as recommended in an ECOG position paper (29), are listed in Table 1.

Table 1: Scales and Subscales testing psychological factors relevant in pediatric obesity assessment

Research studies focusing on cognitions that control eating and movement patterns pre and post obesity surgery are highly needed. First and foremost, the scientifically well-documented addictive aspect of overeating among obese people (30) must be investigated. Addiction in this context means food craving and dependence on overeating (31).

However, this is particularly difficult, firstly because of ever-present food advertising and easy food availability in a society of excesses, and secondly because it leads to a so-called “ironic process,” in which the craving is curbed by inhibitory control characterized by an excessive occupation with not eating. Forbidden foods are banned from the memory, but they acquire a special neuronal importance, such that they are marked as target stimuli in memory search processes. This paradoxically leads to higher availability of the repressed content: thoughts and mental images of forbidden foods are amplified (32). Thus, the alternative approach is to represent salutogenic thoughts and behaviors. This salutogenetic approach puts the balance of good problem-solving ability and self-confident handling of problems as healing factors in opposition to the pathogenic context of control, often called ‘restraint eating’ (cf. 33, among others). So, for instance, thoughts of unfavorable foods (“I will absolutely not eat this chocolate”, “I must not eat that”, and so on) should not be suppressed. Instead these thoughts should be replaced by dietician-formulated sentences like “Everything is allowed in small portions … ” or “I have an appetite for chocolate – I can eat fruit salad with chocolate sprinkles.” The effectiveness of the mentioned healing factors is proven in the area of adiposity research (cf. 34, among others) and also proven as being preventive in studies on eating disorders (cf. 35, among others). Moreover, Kärenen states that more attention must be paid to health-promoting factors in research on eating disorders and obesity (36).

Important aspects for salutogenic eating behavior are “flexible steering of eating behavior”, “hedonic eating”, “adherence to recommendations of nutrition experts”, the “ability to put suggestions concerning exercise and diet into practice”, “nutritional preferences” for healthy instead of fatty food, and “extrinsic” and “intrinsic sports motivation” (17) to pursue health-enhancing physical activity.

Experts and representatives from the International Federation for the Surgery of Obesity – European Chapter (IFSO-EC), European Association for the Study of Obesity (EASO), and EASO’s Obesity Management Task Force (OMTF) issued an international guideline in 2013 at the European Congress on Obesity (ECO) on pre-bariatric surgical requirements for children and youth which explicitly provide not only medical but also “psychological” evaluation (see point 4) and a “post-operative multidisciplinary program”.

Table 2: Interdisciplinary European guidelines on metabolic and bariatric surgery (6).

Evaluation of bariatric surgery risks and benefits

Recommendations resulting from studies evaluating bariatric surgery for adolescents are often based on outdated personality models (8, 9, 37). Thus, some of their findings are questionable. Hence, Felix et al. (8) showed that patients’ mental status improved remarkably within 6 to 33 months after a phobia or depression diagnosis even before surgery. Parikh et al. (39) found no differences regarding weight reduction between patient groups requiring no pre-operative therapy and those for which pre-operative therapy was obligatory. Loux (40) then found evidence that quality of life for morbidly obese adolescents, who claimed to have the same quality of life as those suffering from cancer, significantly rose after surgically-induced weight loss.

In a meta-analysis of 23 studies conducted between 1955 and 2013 (637 patients; gastric band, sleeve gastrectomy, gastric bypass, or biliopancreatic diversion), Black et al. (41) reported that surgical interventions led to a 13.5 kg weight loss within one year and reduced comorbidities. However, it has been argued that possible complications were not properly defined in the selected studies. Jen et al. (42), Michalsky et al. (43), and Inge et al. (44) suggest that the healing process, the subsequent reduction in co-morbidity rate, and post-surgical complications for adolescents are comparable to those experienced by adults. Because of unsatisfactory results, more thoroughly documented long-term studies and guidelines have been recommended.

Although “few studies have been conducted in accordance with scientifically sound criteria”, Treadwell et al. (45) found a trend toward significant weight loss. However only 13% of study participants adhered to both the food and physical activity instructions.

In general, post-operative treatment adherence requires tighter observation for adolescent patients because of the frequency of high-caloric food consumption that may lead to complications and failure (9, 46-48). Some authors are less concerned about pre-operative weight loss predictors and more concerned about post-operative factors influencing treatment success. Rather than general guidance for post-operative therapy, these authors propose an exact evaluation of medical and psychological problems, including eating disorders and disadvantageous or emotionally-induced urges to eat (49-52).

Surgical method and post-operative care, as well as sociodemographic factors like income and education (53), should be considered when evaluating the success of bariatric surgery (15). Pull (54) suggests that the psychological effects of surgery should be investigated to identify factors that affect post-operative weight loss, change in medical comorbidities and quality of life.

With respect to the “Health at any size” campaign (55) that gained popularity in 2001, variables influencing eating habits and health-enhancing physical activities deserve evaluation (56) because patients are still obese or overweight following surgery (57). Although the 1995 SOS study (58) achieved an interdisciplinary approach (59) by operationalizing short scales, research has not been significantly developed. Even the scientifically grounded “Kieler Adipositaspraeventionsstudie” (Kieler Obesity-Prevention Study) (60), which included medical data evaluation, eating habits, and physical activity behavior, failed to change the unsatisfactory standard of requiring interdisciplinary diagnostics and post-surgical evaluation. Fenton (61) notes the relative absence of scientific studies about eating disorders and obesity focusing on salutogenesis over avoidance strategies (62).

If standardized tests were to show that bariatric surgery could benefit patients not only with respect to weight, but also with respect to long-term changes in attitude and behavior regarding eating habits and physical activity, it would gain status as a health-promoting therapy.

A prospective study on interdisciplinary evaluation of pre- and post-operative bariatric surgery conditions

To investigate the pathogenic and salutogenic effects of bariatric surgery on interdisciplinary health, the authors conducted a representative study of 6600 adults and 4400 subjects aged 8 – 18 with a newly developed interdisciplinary instrument (AD-EVA, Adiposity evaluation) based on existing procedures (12, 14, 63, 64); new salutogenically formulated questionnaires (17) were added. Test criteria were determined and items meeting the criteria were selected. Table 3 provides content, example items and test quality information for each questionnaire or subscale.

Table 3. Questionnaire, subscales, and statistical characteristics of the AD – EVA (Adiposity Evaluation): Interdisciplinary test system for the diagnosis and evaluation of obesity and other diseases influenced by eating habits and physical behavior, with two sample items.

QPEC Questionnaire on pathogenic eating cognitions; QSEC Questionnaire on salutogenic eating cognitions; QATO Questionnaire on addiction to overeating; QPED Questionnaire on preclinical eating disorders; QCED Questionnaire on clinical eating disorders; QL Questionnaire on quality of life; QEM Questionnaire on exercise motivation; SNP Scale of nutrition preferences (62).

Assessment was performed pre-operatively and 18 to 24 months post-operatively. Because gastric banding (GB) and gastric bypass (GBP) are the most commonly performed bariatric surgical procedures (59) and they require different post-operative behavioral adaptations, we compared these two methods. Questionnaires were given to 120 patients (33 males and 87 females, aged 16 to 65 years) with morbid obesity (BMI 45.70 ± 6.30 kg/m²) pre-surgery and post-surgery (M=26.8 months). Eighty patients (22 males and 58 females, aged 41.2 ± 11.6 years) underwent gastric bypass surgery and 40 underwent gastric banding surgery. Eight (4 male and 4 female) participants with gastric banding were aged 16 to 18 (pre-operative BMI standard deviation score (BMI_SDS): 3.55 ± 0.44); 24 months post-operatively.

Pre-operatively, no variables regarding eating habits, motivation to exercise, or eating disorders impacted the post-surgery weight difference in regression analysis (R=.63; R²=.40; F=0.943, p=.76). However, post-operative evaluation showed that 7 of 16 determinants were associated with weight loss: bulimia (r = -.45, p < .001; Questionnaire clinical Eatings Disorder, QCED), binge eating disorder (r = -.46, p < .001; QCED), quality of life (r = .29, p < .01; QLS), salutogenic eating cognitions total scale (r = .38, p < .01; Questionnaire for salutogenic Eating Cognitions, QSEC), and the three sub-scales of flexible steering of nutrition intake (r = .35, p < .01), Salutogenic sports attitudes (r = .30, p < .01) and hedonic eating (r = .35, p < .01).

To test the hypothesis, a two-factorial ANOVA over all scales was performed (time: pre-operatively vs. 18 to 24 months post-operatively; groups: GB vs. GBP). Furthermore, differences between the two operative methods were examined through an independent sample t-Test.

Results

As shown in Table 4, BMI was greatly reduced following surgery. Variables influencing weight loss and quality of life such as binge eating and bulimia, addiction to overeating, nutritional preferences for snacks, and fatty food decreased in size. Salutogenic eating habits such as adherence to recommendations, flexible steering of nutrition intake, intrinsic and extrinsic exercise motivation, and salutogenic sports attitude improved 18 to 24 months post-operatively. No differences were found in the subscales restraint eating, hedonic eating, or the pre-clinical eating disorders of preoccupation with weight and shape and preference for healthy nutrition.

Table 4. Change in cognitive variables related to food intake and exercise behavior pre-operatively and 18 to 24 months post-operatively

QPEC: Questionnaire on pathogenic eating cognitions; QSEC: Questionnaire on salutogenic eating cognitions; QATO Questionnaire on addiction to overeating; QPED: Questionnaire on preclinical disorders; QCED: Questionnaire on clinical disorders; QEM: Questionnaire on exercise motivation; SNP: Scale of nutrition preferences; QSEC: Questionnaire on salutogenic sports motivation; QLS: Quality of life scale; F: Two way mixed ANOVA (time x surgical intervention); t: T-Test for independent samples.

Ten variables changed significantly whichever the type of intervention. Interestingly, there was an interaction of post-operative change of direction of many scores with the chosen bariatric method. GBP patients had higher pre-surgical BMIs, and the values of six variables in this group changed positively post-operatively. Despite a poorer pre-operative situation, the post-operative GBP group had better results in comparison to the GB group (p<.05; η2 ≥ .07 to ≤.39). (Table 4, Time x Surgical Intervention).

Table 5 displays results for both groups in seven areas that showed large changes: disinhibition, emotional eating, restraint eating, adherence to recommendations, craving for and addiction to overeating, preference for healthy food, and quality of life. The post-operative results did not differ from those of a representative study of 4400 Austrian and German adults and 6600 children/youths of normal weight. However, no changes occurred with respect to restraint eating, eating pleasure, and preference for healthy food; however, these variables differed only slightly from those of the normal weight reference group. Pre-clinical eating disorders (preoccupation with shape/weight, preference for diets, full or partial discontentment with own body) were twice as high among those who remained obese or overweight compared to normal weight people (Table 5).

Table 5. Pre-operative and post-operative descriptive values for morbidly obese patients compared to normal weight patients

QPEC: Questionnaire on pathogenic eating cognitions; QSEC: Questionnaire on salutogenic eating cognitions; QATO: Questionnaire on addiction to overeating; QPED: Questionnaire on preclinical disorders; QCED: Questionnaire on clinical disorders; QEM: Questionnaire on exercise motivation; SNP: Scale of nutrition preferences; QSEC: Questionnaire on salutogenic sports attitude; QLS: Quality of life scale; ² = the lower the better; ³ = the higher the better.

Discussion

Our finding that gastric bypass, whose effect is attributed to a greater impact on neuro-hormones (65), led to fundamental changes in addiction to overeating scores based on neurocognitive events (66), is consistent with the findings that particular biological factors appear to be the reason for differences in outcomes between gastric banding and bypass (67).

The increased aversion to fatty foods, high calorific sweets, and salty snacks is consistent with normal food aversions induced by bypass. Because of decreased weight and the physical effect “to carry less weight,” we observed a significant increase in exercise motivation and quality of life.

Hormonal and physical alterations causing more favorable satiety and hunger processes may also have led to a change to increase recommended salutogenetic behavior. This change is shown in the significantly increased values of adherence to recommendation, flexible handling of food and salutogenic attitudes toward physical activity and sports.

Those who had undergone bypass had lower post-operative eating disorders scores, whereas scores rose for those with gastric banding. This finding is consistent with previously published results (68-71) and reports from support groups.

However, some eating behavior steering variables remained unchanged. In total, cognitive control remains unimpaired, but it was significantly higher among those with gastric banding, which generally requires more control and restriction by patients compared to those not undergoing this procedure. Eating pleasure, bulimia, binge eating disorder, preoccupation with weight and shape, and preference for healthy food remained unchanged as well. One may thus suggest the existence of a general characteristic that is consistent across body size (12): the view that “thin” is the most beautiful and the desire for being thin is strong. This ideal leads to post-surgical dissatisfaction even after an average weight loss of ten BMI points, as patients’ average final BMI is obese (30 to 35 kg/m²) or overweight (27 to 30 kg/m²). In the case of gastric banding, great cognitive control is necessary, especially with respect to selecting portion sizes. Such control is neuro-cognitively processed as thought suppression. This attempt at thought suppression paradoxically leads to thought fixation. For example, thoughts such as “remember not to empty your plate,” or “don’t eat chocolate or sweets…you will feel ill afterwards” enhances saliva production and results in increased consumption of suppressed food and increased likelihood of binge eating, which may be followed by induced vomiting (72, 73). Unfortunately, gastric band recipients are at risk of developing post-operative eating disorders and require a certain amount of cognitive control that ultimately reduces eating enjoyment

Informed decision making and interdisciplinary follow-up

Although many refer to “compliance” after adolescent bariatric surgery (74, 75), responsibility for success remains largely in the hands of the interdisciplinary personnel and caregivers. It is challenging for an adolescent to cope with his/her desperate desire for an attractive body and think rationally about the future. Even among normally developing adolescents, the ability to evaluate the full consequences of their decisions is questionable, as supported by adolescents’ issues surrounding piercing and tattoos, which they often as adults deeply regret. Since the 1990s, socio-psychological research has shown that “informed decision making” is the most efficient method for complex decision-making processes (76, 77). It is especially important for decisions about bariatric surgery, which, except for gastric banding, are hardly or not reversible at all.

It is crucial to develop a universal catalog of opportunities, easements and requirements for each bariatric treatment and inform patients of risks and benefits for each of these areas. Ideally this discussion would occur via the “dual concern” approach that has demonstrated effectiveness for chronic diseases such as obesity. The method focuses on the extent to which one is concerned with satisfying the needs and interests of the other party and satisfying one’s own needs and interests as well (78). Interdisciplinary experts should communicate in such a way that patients receive sufficient information to make informed decisions. In this way, patients, parents or legal guardians, teachers and others can share responsibility and ease the burden to the professional team, while satisfying both groups (79).

It should be made explicit that the goals of “being healthy” and “getting a more attractive body” post-operatively are more likely to be achieved through patient collaboration with expert teams or advisors. Adolescents, in particular, can be reached via the media, despite a current lack of electronic health app development for decision-making processes and post-operative therapy.

A special emphasis should be placed on acceptance of physical characteristics at odds with prevailing social ideals of beauty. Moreover, education and promotion of salutogenic pleasure of eating, flexible adherence to nutrition, and following physical activity recommendations should be stressed. Techniques for buying, preparing and storing smaller healthy meal portions are generally unknown among adolescents and their parents (80). Although there is a remarkably positive change in attitude toward physical activity and sports motivation following surgery (62), patients’ cardio-pulmonary fitness should be monitored as well, as it is a predictor of obesity.

A comparison study showed that a two-year follow-up program was superior to a minimal post-bariatric follow-up program (81) for adolescents (82). The longer duration is suggested because there is currently very little data regarding post-operative health issues in adolescents, including deficiency symptoms (40). For instance, Beck et al. (83) have found evidence for fluctuations in weight loss and severity of eating disorders after two years. Awareness should be heightened for the often ignored post-bariatric surgery grazing behavior, especially because it may be confused with healthful eating behavior instructions that call for mindful food choices frequently consumed in small amounts throughout the day. Grazing can be “viewed as an unhealthy eating pattern when it is perceived as unplanned, mindless, continuous food consumption” (84). “Picking and nibbling” behavior and post-bariatric surgery anorexia subtypes (85) may also occur.

The ideal type of follow-up therapy remains unknown. A meta-analysis comparing psychotherapeutic intervention versus support groups showed no differences; however, both were more effective than bariatric surgery alone (83).

Recommended interventions often fail due to sociodemographic circumstances. To maximize treatment results, a minimum educational level and privileged social class are generally required (9). Although the number of obese immigrant children has been growing rapidly (86), personnel tend to lack cultural knowledge about foreign eating habits (87,88).

To systematically address the challenges presented herein, our group (65) developed the follow-up scheme presented in Illustration 1 in reference to decision-making heuristics for conservative treatment (89). The scheme includes interdisciplinary follow-up therapy that considers patients’ financial resources, social status, and ethnicity. Diabetes trainings, which have been tested for decades, served as the template (90) in conjunction with consideration for parent and school involvement as well as family conflict (91). The approach follows a 10-year tradition of applied digital media such as Adolescent Cyber-surfing for Health. Not only do pre-surgical and post-surgical advisors require special training, but social workers, psychotherapists, coaches, mediators and peers are also involved. Support groups and clubs should be asked to participate as well.

Figure 1. Pre-operative, peri-operative, and postoperative assessment and intervention

Post-surgical therapy requires clinics with state–of-the-art equipment (92, 93) and a well-developed network of institutions including child protective services, social security offices, sport clubs, and psychologists and psychotherapists trained in treating patients with obesity (94-96). In this way, an adolescent who undergoes surgery has the best chance to become “healthy obese” (7) after weight loss.

References

1. Latner J, Stunkard A. Getting worse: the stigmatization of obese children. Obes Res 2003; 11:452-6.
2. Puhl RM, Latner JD. Stigma, obesity, and the health of the nation’s children. Psychol Bull 2007; 4:557-80.
3. Alavi Z, Calleja NG. Understanding the use of psychotropic medications in the child welfare system: causes, consequences, and proposed solutions. Child Welfare 2012;91:77-94.
4. De Wit L, Luppino F, van Straten A, Penninx B, Zitman F, Cujpers P. Depression and obesity: a meta-analysis of community-based studies. Psychiatry Res 2010; 178,230-235.
5. Luppino FS, de Wit LM, Bouvy PF, et al. Overweight, obesity, and depression: a systematic overview and meta-analysis of longitudinal studies. Arch Gen Psychiatry 2010; 67:220-9.
6. Fried M, Yumuk V, Oppert JM et al. Interdisciplinary European guidelines on metabolic and bariatric surgery. Obes Facts 2013; 6:449-68.
7. Ardelt-Gattinger E, Ring-Dimitriou S, Weghuber, D (Ed). Der gesunde Adipöse (The Healthy Obese). Bern: Huber 2014.
8. Marek RJ, Ben-Porath YS, Windover A, et al. Assessing psychosocial functioning of bariatric   surgerycandidates with the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF). Obes Surg 2013; 11:1864-73.
9. Belanger SB, Wechsler FS, Nademin ME, et al. Predicting outcome of gastric bypass surgery utilizing personality scale elevations, psychosocial factors, and diagnostic group membership. Obes Surg 2010; 20:1361-71.
10. Hopwood CJ, Moser JS. Personality Assessment Inventory internalizing and externalizing structure in college students: invariance across sex and ethnicity. Pers Individ Dif 2011; 50:116-9
11. Odland, A P , Martin, P Perle, J et al. Rates of apparently abnormal MMPI-2 profiles in the normal population. Clin Neuropsychol 2011; 25:1134-44.
12. Stunkard AJ, Wadden TA. Psychological aspects of severe obesity. Am J Clin Nutr 1992;55:524S-32S.
13. Latner J, Cia A, Wendicke A et al.et al. Community-based behavioral weight-loss treatment: long-term maintenance of weight loss, physiological, and psychological outcomes. Behav Res Ther 2013;51:451-9.
14. Pudel V, Westenhöfer J. Fragebogen zum Essverhalten. Göttingen: Hogrefe,1989.
15. Vaidya V. Psychosocial aspects of obesity. Adv Psychos Med 2006; 27:73-84.
16. Lier H, Biringe E, Stubhaug B. The impact of preoperative counseling on postoperative treatment adherence in bariatric surgery patients: A randomized controlled trial. Patient Educ Couns 2012; 87:336-42.
17. Ardelt-Gattinger E, Meindl M (Hg.). AD-EVA (Adipositiy Evaluation). Ein Interdisziplinäres Testsystem zur Diagnostik und Evaluation bei Adipositas und anderen durch Ess- und Bewegungsverhalten beeinflussbaren Krankheiten wie Diabetes, metabolisches Syndrom, Herzkreislauferkrankungen, Erkrankungen oder Störungen des Bewegungsapparats. Bern: Huber, 2009.
18. Greenberg I, Sogg S, Perna F. Behavioral and psychological care in weight loss surgery. Best practive update. Obesity 2009; 17:880-4.
19. Corsica JA, Pelchat ML. Food addiction: true or false? Curr Opin Gastroenterol. 2010; 2:165–9.
20. Müller A, Claes L, Mitchell J et al. Binge eating and temperament in morbidly obese prebariatric surgery patients. Eur Eat Disord Rev 2012; 20:165-9.
21. Dziurowicz-Kozlowska AH, Wierzbicki Z, Lisik W, et al. The objective of psychological evaluation in the process of qualifying candidates for bariatric surgery. Obes Surg 2006;16:196-202.
22. Nakamura T, Mamary E. A qualitative assessment of the My True Body bariatric surgery preparation program. Am J Health Educ 2013;44:278-85.
23. Glinski J, Wetzler, S, Goodman E. The psychology of gastric bypass surgery. Obes Surg 2001;11:581-8.
24. Sogg S, Mori DL. Psychosocial evaluation for bariatric surgery: The Boston interview and opportunities for intervention. Obes Surg 2009;19:369-77.
25. Fabricatore AN, Sarwer DB, Wadden TA, et al. Impression management or real change? Reports of depressive symptoms before and after the preoperative psychological evaluation for bariatric surgery. Obes Surg 2007;17:1213-9.
26. Walfish S, Vance D, Fabricatore AN. Psychological evaluation of bariatric surgery applicants: Procedures and reasons for delay or denial of surgery. Obes Surg 2007;17:1578-83.
27. Lier H, Biringer E, Stubhaug, B. Preoperative predictors of weight loss following bariatric surgery: systematic review. Obes Surg 2012;22:70-89.
28. van Hout GC, Verschure SK, van Heck GL. Psychosocial predictors of success following bariatric surgery. Obes Surg 2005;15:552-60.
29. Braet C, O’Malley G, Weghuber D, Vania A, Erhardt E, Nowicka P, Mazur A, Frelut ML, Ardelt-Gattinger E. The assessment of eating behaviour in children who are obese: a psychological approach. A position paper from the European childhood obesity group. Obes Facts. 2014;7(3):153-64. doi: 10.1159/000362391. Epub 2014 May 10.
30. Davis C, Curtis C, Levitan R, Carter J, Kaplan A, Kennedy J. Evidence that ‘food addiction’ is a valid phenotype of obesity. Appetite, 2011; 57(3): 711-717.
31. Volkow, N., Wang, G., Tonesi, D., & Bailer, R. D. Obesity and Addiction. Neurobiological Overlaps. Obesity Reviews 2013; 14: 2-8.
32. Soetens, B., Braet, C., Dejonckheere, P., & Roets, A. ‘When Suppression Backfires’ The Ironic Effects of Suppressing Eating-related Thoughts. Journal of health psychology, 2006;11(5): 655-668.
33. Lindström, B., & Eriksson, M. (). Salutogenesis. Journal of Epidemiology and community health, 2005; 59(6):440-442.
34. Meier, S., Kohlmann, C. W., Eschenbeck, H., & Gross, C. Coping in children and adolescents with obesity: The costs and benefits of realistic versus unrealistic weight evaluations. Applied Psychology: Health and Well‐Being, 2010; 2(2): 222-240.
35. Celio, A. A., Winzelberg, A. J., Wilfley, D. E., Eppstein-Herald, D., Springer, E. A., Dev, P., & Taylor, C. B. Reducing risk factors for eating disorders: comparison of an Internet-and a classroom-delivered psychoeducational program. Journal of consulting and clinical psychology, 2000; 68(4): 650.
36. Keränen, A. M., Strengell, K., Savolainen, M. J., & Laitinen, J. H. (). Effect of weight loss intervention on the association between eating behaviour measured by TFEQ-18 and dietary intake in adults. Appetite, 2011; 56(1): 156-162.
37. Bonfà, F.; Marchetta, L.; Avanzi, M. et al. Exploratory evaluation of an obese population seeking bariatric surgery in an Italian public service. Eat Weight Disord 2010;15: 119-26.
38. Felix LG, Soares M, Da Nóbrega M. Protocolo de assistência de enfermagem ao paciente em pré e pós-operatório de cirurgia bariátrica. Nursing care protocol to the patient before and after bariatric surgery. Revista brasileira de enfermagem 2012;65: 83-91.
39. Parikh , Dasari M, Mcmacken M et al. Does a preoperative medically supervised weight loss program improve bariatric surgery outcomes? A pilot randomized study. Surgical endoscopy 2012, Vol.26(3), pp.853-61.
40. Loux TJ, Haricharan RN, Clements RH, et al. Health-related quality of life before and after bariatric surgery in adolescents. J Pediatr Surg 2008; 43:1275-9.
41. Black JA, White B, Viner RM, Simmons RK. Bariatric surgery for obese children and adolescents: a systematic review and meta‐analysis. Obes Rev 2013; 14:634-660.
42. Jen HC, Rickard DG, Shew SB, et al. Trends and outcomes of adolescent bariatric surgery in California, 2005–2007. Pediatrics 2010; 126:e746-53.
43. Michalsky M, Kramer RE, Fullmer MA, et al. Developing criteria for pediatric/adolescent bariatric surgery program. Pediatrics 2011; 128:65-70.
44. Inge TH, Zeller MH, Jenkins TM, et al. Perioperative outcomes of adolescents undergoing bariatric surgery: The Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. JAMA Pediatr 2014; 168:47-53. doi:10.1001/jamapediatrics.2013.4296.
45. Treadwell JR, Sun F, Schoelles F. Systematic review and meta-analysis of bariatric surgery for pediatric obesity. Ann Surg 2008; 248:763-76.
46. Kumar S, Zarroug AE, Swain JM. Adolescent bariatric surgery. Abdom Imaging 2012;37:725-9.47.Davin S, Taylor N. Comprehensive review of obesity and psychological considerations for treatment, Psychol Health Med 2009;14:716-25.
47. Davin S, Taylor N. Comprehensive review of obesity and psychological considerations for treatment, Psychol Health Med 2009;14:716-25
48. Marcus MD, Kalarchian M. Binge eating in children and adolescents. Int J Eat Disord 2003; 34:S47-57.
49. Xanthakos SA. Bariatric surgery for extreme adolescent obesity: indications, outcomes, and physiologic effects on the gut-brain axis. Pathophysiology 2008;15:135-147.
50. Burgmer R, Grigutsch K, Zipfel S, et al. The influence of eating behavior and eating pathology on weight loss after gastric restriction procedures. Obes Surg 2005;15:684-91.
51. Saunders R. Post-surgery group therapy for gastric bypass patients. Obes Surg 2004;14:1128-31.
52. Guerdjikova A, West-Smith L, McElroy Set al. Emotional eating and emotional eating alternatives in subjects undergoing bariatric surgery. Obes Surg 2007;17:1091-6.
53. Reinehr T. Adipositas im Kindes- und Jugendalter: Folgeerkrankungen, Präventionschancen und Wirksamkeit von Therapieansätzen. Kinder- und Jugendarzt 2006;37:1-5.
54. Pull CB. Current psychological assessment practices in obesity surgery programs: what to assess and why. Curr Opin Psychiatry 2010;23:30-6.
55. Miller WC, Jacob AV. The health at any size paradigm for obesity treatment: the scientific evidence. Obes Rev 2001;2:37-45.
56. Pataky Z, Carrard I, Golay A. Psychological factors and weight loss in bariatric surgery.Curr Opin Gastroenterol 2011;27:167-73.
57. Hell E, Miller K, eds. Morbide Adipositas. Landsberg: Ecomed, 2000.
58. Sjöström CD, Lissner L, Wedel H, Sjöström L. Reduction in incidence of diabetes, hypertension and lipid disturbances after intentional weight loss induced by bariatric surgery: the SOS Intervetion Study. Obesity 1999;7:477-84.
59. Woolford SJ, Clark SJ, Gebremariam A, et al. To cut or not to cut: physicians’ perspectives on referring adolescents for bariatric surgery. Obes Surg, 2010;20:937- 945.
60. Czerwinski-Mast M, Langnäse K, Danielzik S, et al. Kieler Adipositaspräven- tionsstudie (KOPS) – Konzept und erste Ergebnisse der Vierjahres-Nachuntersuchungen. Bundesgesundheitsblatt – Gesundheitsforschung – Gesundheitsschutz 2003;46:727-31.
61. Fenton C, Brook F, Spencer N et al. Sustaining a positive body image in adolescence: an assets‐based analysis, Health Soc Care Commun 2010;18:189-98.
62. Ardelt-Gattinger E, Meindl M, Ring-Dimitriou S, et al. Wie hoch ist der Preis der Gewichtsabnahme? Interdisziplinäre Evaluation chirurgischer Adipositastherapie. In: Ardelt-Gattinger E, Miller K, Weiner R, eds. Adipositas interdisziplinär. München: Marseille-Verlag, 2013.
63. Canetti L, Berry E, Yoel E. Psychosocial predictors of weight loss and psychological adjustment following bariatric surgery and weight-loss program: the mediating role of emotional eating. Int J Eat Disord 2009;42:109-17.
64. Ouwehand C, Papies EK. Eat it or beat it. The differential effects of food temptations on overweight and normal-weight restrained eaters. Appetite, 2010;55:56-60.
65. O’Brien PE. Bariatric surgery: mechanisms, indications and outcomes. J Gastroenterol Hepatol, 2010;25:1358-65.
66. Robinson T, Berridge T. Addiction. Annu Rev Psychol 2003;54:25-53.
67. Herpertz S, Kielmann R, Wolf AM, et al. Do psychosocial variables predict weight loss or mental health after obesity surgery? – a systematic review. Obes Res. 2004;12:1554-69.
68. Sugerman HJ, Kellum JM, Engle KM, et al. Gastric bypass for treating severe obesity. Am J Clin Nutr 1992;55:560-566.
69. Marino JM, Ertelt TW, Lancaster K, Steffen K, Peterson L, de Zwaan M. The emergence of eating pathology after bariatric surgery: a rare outcome with important clinical implications. Int J Eat Disorder 2012;45:179-84.
70. Mitchell J, Steffen K. The interface between eating disorders and bariatric surgery. Eating Disorders Review 2009;20:1.
71. Weghuber D, Miller K, Ardelt-Gattinger E et al. Interdisciplinary score for the evaluation of bariatric treatment in obese children (BAREV-C). Int J Disabil Hum Dev. 2012;12:37-43.
72. Wegner DM. Ironic processes of mental control. Psychol Rev 1994;101:34-52.
73. Stroebe W. Obesity as fate: the cognitive regulation of eating behaviour. Psychologische Rundschau 2002;53(1):14-22.
74. Padhy B M, Gupta P, Yogendra K. Analysis of the compliance of informed consent documents with good clinical practice guideline. Contemp Clin Trials 2011;32:662-6.
75. Swan DJ, Collins MA. Sign on the dotted Line. The informed consent process (ICP) as induced compliance. J Appl Soc Psychol 2008;38:2637-47.
76.  Manson N, O’Neill O. Rethinking informed consent in bioethics. Cambridge: Cambridge University Press 2008.
77. Armstrong ML, Ekmark E, Brooks B. Body piercing: promoting informed decision making. J Sch Nurs 1995;11:20-25.
78. Dimatteo MR. The role of effective communication with children and their families in fostering adherence to pediatric regiments. Patient Educ Couns 2004;339-44.
79. McClellan CB, Cohen LL. Family functioning in children with chronic illness compared with healthy controls review. J Pediatr 2007;150:221-3.
80. Barre LK, Pratt SI, Bartels SJ. Eating behaviors of obese persons with serious mental illness. Obesity 2011;19:S209.
81. Wirt A, Wabitsch M, Hauer H et al. S3-Leitlinien Prävention und Therapie der Adipositas. Adipositas 2014;8:179-221.
82. Burgmer R, Legenbaue T, Müller A et al. Psychological outcome 4 years after restrictive bariatric surgery. Obes Surg 2014; 24:1670-8.
83. Beck NN, Melsen M, Støving RK. Psychological characteristics and associations with weight outcomes two years after gastric bypass surgery: postoperative eating disorder symptoms are associate with weight loss outcomes. Eating Behavior 2012;13:394-401
84. Zunker C, Karr T, Saunders R et al. Eating behaviors post-bariatric surgery: a qualitative study of grazing. Obes Surg 2012; 22:1225-31.
85. Conceição E, Orcutt M, Mitchell J, et al. Eating disorders after bariatric surgery: a case series. Int J Eat Disoder 2013; 46:274-9.
86. Butler J. Gesundheitsberichtserstattungs-basierte Gesundheitsförderung für sozial benachteiligte Bevölkerungsgruppen – Bezirk Berlin-Mitte, Plan- und Leitstelle Gesundheit. In: Butler J, Prey T, eds. Gesundheit und Integration – Ein Handbuch für Modelle guter Praxis (2 ed.). Beauftragte der Bundesregierung für Migration, Flüchtlinge und Integration: Berlin, 2007.
87. Watters C. Emerging paradigms in the mental health care of refugees. Soc Sci Med 2001; 52:1709-18.
88. Capozza D, Trifiletti E, Vezzali L et al. Can intergroup contact improve humanity attributions? Int J Psychol 2013; 48:527-41.
89. Wiegand S, Dannemann A, Vahabdazeh Z, Ernst M. Wer braucht was? Neue Ansätze der multidisziplinären Diagnostik und Therapie adipöser Kinder und Jugendlicher in einer multiethnischen Großstadt. Bundesgesundheitsblatt, 2005;48:307-14.
90. Waitzfelder B, Pihoker N, Klingensmit G et al. Adherence to guidelines for youths with diabetes mellitus. Pediatrics 2011;128: 531-538.
91. Mielck A, Reitmeir P, Rathmann W. Knowledge about diabetes and participation in diabetes training courses: the need for improving health care for diabetes patients with low SES. Exp Clin Endocrinol Diabetes 2006; 114:240-8.
92. Silberhumer GR, Miller K, Pump A et al. Long-term results after laparoscopic adjustable gastric banding in adolescent patients. Surg Endosc 2011;25:2993-9.
93. Miller K. Adjustable gastric banding in adolescents and children. In: Widhalm K, Prager G, eds. Morbid obesity in adolescents. Conservative treatment and surgical approaches. Springer, 2015.
94. Sabbioni MEE, Dickson MH, Eychmueller S, et al. Intermediate results of health related quality of life after vertical banded gastroplasty. Int J Obes Relat Metab Disord 2002; 26:277-80.
95. Hudson SM, Dixon JB, O’Brien PE. Sweet eating is not a predictor of outcome after lap-band® placement. Can we finally bury the myth? Obes Surg 2002; 12:789-794.
96. Lent M, Swencionis C. The association between addictive personality and maladaptive eating behaviors in adults seeking bariatric surgery. Obesity 2011;19: S138.