Weight Loss in Children and Adolescents
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Background: 15% of children and adolescents in Germany are overweight, including 6.3% who are affected by obesity. The efficacy of conservative weight-loss treatments has been demonstrated, but there has not yet been a detailed analysis of their efficacy in terms of the amount of weight loss that can be expected. We re-evaluated the available evidence on this question, with particular attention to the methodological quality of clinical trials, in order to derive information that might be a useful guide for treatment.
Methods: We conducted a systematic literature search of Medline for the period May 2008 (final inclusion date for a 2009 Cochrane Review) to December 2013. The identified studies were analyzed qualitatively.
Results: 48 randomized controlled clinical trials with a total of 5025 participants met the predefined inclusion criteria for this analysis. In the ones that met predefined criteria for methodological quality, conservative weight-loss treatments led to weight loss in amounts ranging from 0.05 to 0.42 BMI z score (standard deviation score of the body mass index) over a period of 12–24 months. Information on trial dropout rates was available for 41 of the 48 trials; the dropout rate was 10% or higher in 27 of these (66%), and 25% or higher in 9 (22%).
Conclusion: The available evidence consistently shows that only a modest degree of weight loss can be expected from conservative treatment. Families seeking treatment should be informed of this fact. Future research should focus on determining predictive factors for therapeutic benefit, and on the evaluation of additional types of psychological intervention to promote coping with obesity.
About 15% of all children and adolescents in Germany are overweight, including 6.3% who are affected by obesity (1). The prevalence of obesity has been stable in recent years in Germany (2), and emphasis is increasingly being laid on prevention (3), but the treatment of children and adolescents with obesity remains an important matter for health-care policy. The likelihood that childhood obesity will persist into adulthood (4), the elevated risks of somatic (5) and mental (6) comorbidity, stigmatization and the psychosocial impairment that it causes (7), and high health-care costs (8) are all reasons why effective treatments for obesity are needed. Overweight and obesity affects many children and adolescents, but relatively few of them participate in the available treatment programs (9, 10).
In the German evidence-based guidelines on the treatment of obesity in childhood and adolescence, conservative (non-pharmacological) weight-loss treatments are recommended, with the goal of long-term improvement in nutritional and exercise habits (11). A multimodal lifestyle intervention is advised, including dietary, physical activity–based, and behavior therapy components. It is stated that adjuvant pharmacotherapy or bariatric surgery for extreme obesity should only cautiously be offered to adolescents, and only after the failure of conservative treatment (11).
The efficacy of conservative treatment is deemed to be well established, but the most recent Cochrane meta-analysis (2009) (10) showed that the effect size is small: the mean amount of weight loss after 12 months of conservative treatment was 0.04 and 0.14 BMI z score (11) (standard deviation score of the body mass index) in children and adolescents, respectively (these figures are derived from two trials for each of the two age groups). Many trials have compared the effects of two or more conservative treatments against each other, but the overall amount of weight reduction that can be expected from any such treatment needs to be assessed in more detail.
In this article, we summarize the current state of the scientific evidence and qualitatively analyze the available research publications. In assessing the findings, we consider not only the amount of weight loss over the intermediate term, but also patient adherence, dropout rates, and the methodological quality of the trials.
We performed a qualitative analysis in order to assess the broadest possible spectrum of available randomized controlled trials; the eligible trials were too few, and too heterogeneous, to enable quantitative analysis (see eMethods). We searched the literature for research on the efficacy of weight-loss treatments in children and adolescents, published from May 2008 to December 2013. The May 2008 starting point was chosen because this had been the final inclusion date for a 2009 Cochrane meta-analysis that took all prior publications into account (10). The results of the literature search are shown in the PRISMA flow diagram (12, 13) (Figure). The inclusion criteria for trials were as follows: a randomized controlled design; an intervention consisting of dietary, physical activity–based, or behavior therapy (at least one of these three); at least 6 months of follow-up after the start of treatment; BMI and/or BMI z score as a study endpoint; and use of the internationally accepted definition of obesity, i.e., BMI z score ≥ 2, or, alternatively, being in the 97th BMI percentile or above (11). The methodological quality of trials was evaluated with the aid of seven predefined criteria, in accordance with current recommendations (eMethods, eTable 2 [10, e2]):
- Statistical power analysis for BMI or BMI z score
- Intention-to-treat analysis
- Description of the randomization procedure
- Reporting of adverse events
- Information about adherence (participation rate)
- Information about dropout rate during the intervention
- Information about loss to follow-up.
The methods of analysis are described in detail in the supplementary materials (eMethods), as are the methods of data extraction and the general characteristics of the clinical trials (eMethods, eTable 1).
The overall number of randomized participants in the 48 trials that were included in this analysis was 5025 (mean of 104.7 participants per trial, standard deviation 75.8, range 18–475). A selection of trials meeting predefined methodological criteria is shown in Table 1a.
In four trials (14–18) that met all seven of the methodological quality criteria, the reduction of BMI z score after 12 months of treatment ranged from 0.05 to 0.22. In four further trials (19–23) that met at least five of the criteria (including power analysis and intention-to-treat analysis) and that included at least 100 participants who were followed up for at least 12 months, the corresponding range was 0.14 to 0.39 (Table 1a).
In summary, in these eight trials (which were the best eight among the 48 included in the study, according to the predefined quality criteria), the mean weight loss among the child and adolescent participants after 12 months of treatment ranged from 0.05 to 0.39 BMI z score. Four of these eight trials also contained data in terms of BMI z score about weight loss at 24 months: these figures ranged from 0.08 to 0.42. Table 2 contains an illustration of what a BMI z score reduction of 0.3 after 12 months of treatment implies, with simultaneous consideration of the normal growth process; we use extrapolated values of a German reference population for this purpose (31, 32). In a 15-year-old-girl initially weighing 102.0 kg, this degree of BMI z score reduction would correspond to an absolute weight loss of 4.8 kg; in an 8-year-old boy initially weighing 40 kg, it would correspond to an absolute weight gain of 3.5 kg (Table 2).
Out of a total of 23 reports of trials in which treatment was compared with routine care or a waiting list condition, 18 contained BMI z score data at 6 or 12 months from the start of treatment. Only 7 of these 18 trials (24–30) revealed a statistically significant difference between groups with respect to BMI z score changes; furthermore, most of them had methodological deficiencies that lessened the informative value of the findings. Table 1b contains an overview of the reported intergroup differences at 6 and 12 months, without taking account of the methodological quality of each individual trial or of heterogeneity across trials. The rates of dropout and of loss to follow-up indirectly reflect the participants’ acceptance and subjective views of the interventions, as well as their practical applicability in everyday life. In the included trials, these rates ranged from 0% to 50% and from 0% to 71%, respectively. Out of the 41 trials for which such information was reported, the drop-out rate was above 10% in 27, and above 25% in 9 (eTable 2). Data on loss to follow-up was reported in 45 trials: this rate was above 10% in 31 trials, and above 25% in 20. The inclusion rate, i.e., the percentage of screened candidates who went on to be randomized, varied from 10% to 100% across trials, depending on the pathways of participant recruitment, and was less than 60% in 23 trials (nearly half of all trials).
The available data on the efficacy of non-pharmacological treatments for obesity in children and adolescents yield a heterogeneous picture. The interpretability of the findings is limited by the variable methodological quality across trials; by the heterogeneity of the study populations with respect to age, initial weight, and social background; by differences in the nature, quantity, and intensity of interventions; and by the use of varying endpoints and follow-up intervals. For all these reasons, the results cannot be generalized.
Although scientific evidence (10) supports the efficacy of conservative weight-loss treatments, little attention has been paid to the amount of weight loss that can be realistically expected from such treatments. The high-quality clinical trials that we analyzed revealed BMI z score reductions ranging from 0.05 to 0.39 one year after the start of treatment. This implies that most children and adolescents with obesity cannot expect their weight to be normalized by conservative treatment over the intermediate term (for calculated examples, cf. Table 2). A patient who achieves an average result in one of the available interventional programs will exit from the officially defined category of “obesity” only if his or her initial BMI was not very far above the threshold value. Conceivably, the main therapeutic value of conservative weight-loss treatment may lie in the reduction of cardiovascular risk and comorbidities: significant improvements in insulin sensitivity, blood pressure, and lipid profiles have been demonstrated even with only mild or moderate degrees of weight loss (33). Conservative weight-loss treatment has also been found to bring about sustained improvements in nutritional and exercise behavior, which, in the long term, may lower the risk of obesity-associated diseases (34). Self-reported data concerning lifestyle should always be interpreted with caution because of a tendency of social desirability in participants’ answers. An improvement in quality of life as a result of conservative weight-loss treatment has been reported in one trial; however, it was only short-lasting (35). Moreover, the trials that have been performed to date in which psychological variables were measured do not permit any secure judgment as to whether a positive effect on quality of life also extends to participants who did not lose weight as the result of the intervention.
In assessing the effects of weight-loss treatment, one should be aware of the lack of information about the further course of those trial participants’ weight status who were lost to follow-up. In cases where participants went on to lose less than average amounts of weight after their last observation, the overall effect of the intervention would actually be smaller than reported. Efforts to lose weight can, in fact, promote weight gain in the long run (36). On the other hand, it is also conceivable that modest short-term and intermediate-term effects might develop into more substantial weight loss later on. This question can only be answered on the basis of longitudinal observations over several years including intensive efforts to prevent losses to follow-up. The available data suggest that some subgroups of children and adolescents may respond better to weight-loss treatment than others. This conclusion is based on BMI z-score changes ranging all the way from –0.9 to +0.70 in the included trials—provided that this does not simply reflect a random distribution of data.
Predictors of therapeutic success should, therefore, be an object of study in future clinical trials. For example, it would be useful to document the weight status of the parents of each participant; parental weight status has already been shown to be of major predictive significance, particularly for younger children (4). Clinical research in this area to date has also paid too little attention to the documentation of adverse events, which should be checked for repeatedly at close intervals, because of the possibility that weight-loss treatment in children and adolescents might have negative consequences for long-term weight development and for mental health. Mental disorders are known to be more prevalent in people with obesity (6); nonetheless, a detailed psychological and/or psychiatric evaluation is not yet a standard component of behavior-therapeutic lifestyle interventions for obesity.
The strengths and limitations of this study
Our detailed analysis of the effects of weight-loss treatment over time in children and adolescents with obesity (absolute changes from the baseline to the follow-up examination) is one of the strengths of this study. Another is that our evaluation of randomized controlled clinical trials took account of their methodological limitations through the use of objective quality criteria. We were able to assess the therapeutic potential as well as the limitations of conservative weight-loss treatment in this age group by comprehensive extraction of the relevant data, including all available information on adherence, dropout, and loss to follow-up. A final strength of this study is that it constitutes an updated review of a field of research that is of great relevance to the medical care of a risk population.
The informativeness of this study is limited by the lack of a quantitative analysis of treatment effects. Due to the heterogenity of the available studies and non-generalizability of results, performance of a meaningful meta-analysis was not feasible. A further limitation of this study is that the methodological quality criteria were all applied with equal weight. Moreover, the inclusion of further endpoints in addition to BMI and BMI z score (i.e., indicators of other aspects of the patient’s somatic or psychological condition) would have been desirable, but was not possible because data of this type were lacking.
The results reported here have a number of clinical implications. The high dropout rates and even higher rates of loss to follow-up arouse concern about what might happen to these patients’ health beyond the end of the intervention. Families seeking treatment usually have high hopes that their child will enjoy sustained weight loss, resulting, in the best case, in a normal weight. Many of the available intervention programs demand an intensive effort from participants over a long period of time, sometimes with multiple appointments each week for the patient and at least one accompanying parent. The realization that these major efforts tend to yield relatively modest benefits may be one reason why the interventions are often broken off prematurely. It may be that many families already know this even before treatment is started; if so, this might account for the low inclusion rates of the clinical trials, in comparison to the number of families to whom treatment was offered. The utilization rate may also be kept low by other factors, including socioeconomic barriers. There is no reliable way to determine the actual percentage of obese children and adolescents who would be willing to undergo weight-loss treatment.
There is also a danger that patients who do not lose weight while under treatment will interpret this as a personal failure. Research on the stigmatization of persons with obesity indicates that discrimination is widely experienced within the family, and in health-care settings as well (37). A common stigmatizing attitude is the assumption that the individual with obesity bears full personal responsibility for his or her abnormal weight; feelings of failure and shame are the result. Patients with low self-esteem often internalize such attitudes which leads to self-stigmatization (38).
Regardless of whether weight is ultimately lost, participation in a treatment program reveals that the patient is intensely concerned about the problem. Weight looms large in everyday life in comparison to other typical developmental issues, and the patient’s self-esteem is largely determined by the success or failure of the attempt to lose weight—all the more so if the parent–child relationship tends to focus on weight loss, to the exclusion of other matters. In vulnerable children and adolescents, excessive preoccupation with weight can lead to dysfunctional weight-control mechanisms and to loss of self-esteem, potentially culminating in depressive episodes with social isolation (39). Unhealthy weight-control mechanisms are known to be a potential precursor of eating disorders; such disorders, once they arise, make it more likely that the patient will continue to gain weight (40). Resignation, with the abandonment of all efforts to lead a healthy lifestyle, is another possible reaction to the failure of treatment. On the other hand, children and adolescents might derive various benefits from participation in a weight-loss program that are independent of weight loss per se, for example, a more healthy lifestyle, improved quality of life, and more regular medical check-ups. Another positive scenario is that a patient who has achieved only a modest degree of weight loss might draw the conclusion that the ability to control his or her own weight is, in fact, limited, and thus develop a new, emotionally more helpful attitude to obesity.
To prevent treatment failure as far as possible, physicians should take care to inform the parents and the affected children or adolescents early on about the degree of weight loss that they can realistically expect from the currently available treatments, and about their potential adverse effects, as determined from the consistent findings of clinical trials. Unrestricted recommendations to undergo conservative treatment, with an exclusive focus on weight loss, may have the adverse consequences already mentioned above; additionally, a disappointing experience with such treatment may end up weakening the patient’s (and the family’s) confidence in medical care in general, possibly prompting a total withdrawal from care. It is very important for the patient to remain in regular contact with a physician over the long term, in view of the elevated risk of illnesses associated with obesity (regular check-ups can enable, for example, the timely diagnosis of hypertension). If the patient expresses willingness to be treated for obesity, the physician should discuss the patient’s and the family’s expectations with them extensively, so that they will be able to deal with the problem of obesity constructively. On the other hand, if the family decides against conservative treatment for obesity because of the limited prospect of success, this decision should be respected, and the family should continue to benefit from the physician’s medical support in dealing with obesity. In view of the fact that conservative methods can generally only bring about a modest degree of weight loss, one may well ask whether the proof of failure of conservative methods ought still to be considered a prerequisite for the consideration of bariatric surgery, as it is at present (11). It might be reasonable to loosen this requirement when extreme obesity threatens to severely impair the physical and mental health of a young patient.
The goal of treating a chronic disease is, above all, to help the patient cope with it. Since obesity can be seen as a chronic disease, it would seem advisable to refocus the treatment away from weight loss as a goal in itself, and toward better coping with the health problem. Interventions should be provided that are aimed at the following targets: improved quality of life and self-esteem, a more positive body image, dealing with stigmatization, overcoming social isolation, a more healthy lifestyle regardless of the amount of weight that is lost, and regular check-ups in primary care. Especially in the case of young children, the parents should be involved in the treatment process, so that stigmatization within the family can be avoided. The acceptance and efficacy of coping-oriented interventions that are intended to improve the patient’s quality of life and psychosocial functioning should be the primary endpoints of future clinical trials in this field.
This study was supported by the German Federal Ministry of Education and Research (BMBF, project no. 01GI1120A/B) and was integrated within the German Competence Network Obesity (Consortium “Youths With Extreme Obesity”).
Conflict of interest statement
The authors have received financial support from the German Federal Ministry of Education and Research for a research project that they initiated within the Consortium “Youth With Extreme Obesity” (project no. 01GI1120A/B).
Manuscript submitted on 27 March 2014, revised version accepted on
10 September 2014.
Translated from the original German by Ethan Taub, M.D.
Dipl.-Psych. Yvonne Mühlig, LVR-Klinikum Essen,
45147 Essen, Germany
@For eReferences please refer to:
eMethods, eTables, eFigure:
Dipl.-Psych. Mühlig, Prof. Dr. med. Hebebrand
Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology, Diabetes and Obesity Unit, University of Ulm: Prof. Dr. med. Wabitsch, Dr. biol. hum. Moss
|1.||Kurth BM, Schaffrath Rosario A: Die Verbreitung von Übergewicht und Adipositas bei Kindern und Jugendlichen in Deutschland. Ergebnisse des bundesweiten Kinder- und Jugendgesundheitssurveys (KiGGS). Bundesgesundheitsbl 2007; 50: 736–43. CrossRef MEDLINE|
|2.|| Blüher S, Meigen C, Gausche R, et al.: Age-specific stabilization in obesity prevalence in German children: a cross-sectional study from 1999 to 2008. |
Int J Ped Obes 2011; 6: e199–e206. CrossRef MEDLINE
|3.|| Waters E, de Silva-Sanigorski A, Hall BJ, et al.: Interventions for preventing |
obesity in children (review). Cochrane Database Syst Rev 2011; 7:
DOI: 10.1002/14651858.CD001871.pub3. CrossRef MEDLINE
|4.||Whitaker RC, Wright JA, Pepe MS, Seidel KD, Dietz WH: Predicting obesity in young adulthood from childhood and parental obesity. New Engl J Med 1997; 337: 869–73. CrossRef MEDLINE|
|5.|| Ebbeling CB, Pawlak DB, Ludwig DS: Childhood obesity: public-health crisis, |
common sense cure. Lancet 2002; 360: 473–82. CrossRef MEDLINE
|6.||Hebebrand J, Herpertz-Dahlmann B: Psychological and psychiatric aspects of pediatric obesity. Child Adolesc Psychiatr Clin N Am 2009; 18: 49–65. CrossRef MEDLINE|
|7.||Puhl RM, Latner JD: Stigma, obesity and the health of the nation’s children. Psychol Bull 2007; 133: 557–80. CrossRef MEDLINE|
|8.||Knoll KP, Hauner H: Kosten der Adipositas in der Bundesrepublik Deutschland – Eine aktuelle Krankheitskostenstudie. Adipositas 2008; 2: 204–10.|
|9.||Finne E, Reinehr T, Schäfer A, Winkel K, Kolip P: Overweight children and adolescents – is there a subjective need for treatment? Int J Pub Health 2009; 54: 112–6. CrossRef MEDLINE|
|10.||Oude Luttikhuis H, Baur L, Jansen H, et al.: Interventions for treating obesity in children (review). Cochrane Database of Syst Rev 2009; 3: 1–57. MEDLINE|
|11.||Wabitsch M, Moss A (federführend für die Arbeitsgemeinschaft Adipositas im Kindes- und Jugendalter): Evidenzbasierte Leitlinie zur Therapie der Adipositas im Kindes- und Jugendalter. S3-Leitlinie, Version 2009. www.aga.de/adipositas-gesellschaft.de/fileadmin/PDF/Leitlinien/Leitlinie-AGA-S3–2009.pdf . (Last accessed on 27 January 2014).|
|12.||Ziegler A, Antes G, König IR: Bevorzugte Items für systematische Übersichten und Meta-Analysen: Das PRISMA-Statement. Dtsch Med Wochenschr 2011; 136: e9–e15. CrossRef|
|13.||Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group: Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009; 6: e1000097:doi10.1371/journal.pmed1000097 (last accessed on 27 January 2014). MEDLINE|
|14.||Mirza NM, Palmer MG, Sinclair KB, et al.: Effects of a low glycemic load or a low-fat dietary intervention on body weight in obese Hispanic American children and adolescents: a randomized controlled trial. Am J Clin Nutr 2013; 97: 276–85. CrossRef MEDLINE PubMed Central|
|15.||Croker H, Viner RM, Nicholls D, et al.: Family-based behavioural treatment of childhood obesity in a UK National Health Service setting: randomized controlled trial. Int J Obes ) 2012; 36: 16–26. CrossRef MEDLINE PubMed Central|
|16.||Wake M, Lycett K, Clifford SA, et al.: Shared care obesity management in 3–10 year old children: 12 month outcomes of HopSCOTCH randomised trial. BMJ 2013; 346: f3092. CrossRef MEDLINE PubMed Central|
|17.||Nguyen B, Shrewsbury VA, O’Connor J, et al.: Two-year outcome of an adjunctive telephone coaching and electronic contact intervention for adolescent weight-loss maintenance: the Loozit randomized controlled trial. Int J Obes 2013; 37: 468–72. CrossRef MEDLINE|
|18.||Nguyen B, Shrewsbury VA, O’Connor J, et al: Twelve-month outcomes of the loozit randomized controlled trial: a community-based healthy lifestyle program for overweight and obese adolescents. Arch Pediatr Adolesc Med 2012; 166: 170–7. CrossRef MEDLINE|
|19.||Ford AL, Bergh C, Södersten P, et al.: Treatment of childhood obesity by retraining eating behaviour: randomized controlled trial. BMJ 2009; 340: b5388. CrossRef MEDLINE|
|20.||De Niet J, Timman R, Bauer S, et al.: The effect of a short message service maintenance treatment on body mass index and psychological well-being in overweight and obese children: a randomized controlled trial. Pediatr Obes 2012; 7: 205–19. CrossRef MEDLINE|
|21.||Collins CE, Okely AD, Morgan PJ, et al.: Parent diet modification, child activity, or both in obese children: an RCT. Pediatrics 2011; 127: 619–27. CrossRef MEDLINE|
|22.||Okely AD, Collins CE, Morgan PJ, et al.: Multi-site randomized controlled trial of a child-centered physical activity program, a parent-centered dietary-modification program, or both in overweight children: the HIKCUPS study. J Pediatr 2010; 157: 388–94. CrossRef MEDLINE|
|23.||Magarey AM, Perry RA, Baur LA, et al.: A parent-led family-focused treatment program for overweight children aged 5 to 9 years: the PEACH RCT. Pediatrics 2011; 127: 214–22. CrossRef MEDLINE|
|24.||Bocca G, Corpeleijn E, Stolk RP, Sauer PJ: Results of a multidisciplinary treatment program in 3-year-old to 5-year-old overweight or obese children: a randomized controlled clinical trial. Arch Pediatr Adolesc Med 2012; 166: 1109–15. CrossRef MEDLINE|
|25.||Diaz RG, Esparza-Romero J, Moya-Camarena SY, Robles-Sardin AE, Valencia ME: Lifestyle intervention in primary care settings improves obesity parameters among Mexican youth. J Am Diet Assoc 2010; 110: 285–90. CrossRef MEDLINE|
|26.||Janicke DM, Sallinen BJ, Perri MG, et al.: Comparison of parent-only vs family-based interventions for overweight children in underserved rural settings: outcomes from project STORY. Arch Pediatr Adolesc Med 2008; 162: 1119–25. CrossRef MEDLINE PubMed Central|
|27.||Pedrosa C, Oliveira BM, Albuquerque I, Simoes-Pereira C, Vaz-de-Almeida MD, Correia F: Markers of metabolic syndrome in obese childen before and after 1-year lifestyle intervention progam. Eur J Nutr 2011; 50: 391–400. CrossRef MEDLINE|
|28.||Savoye M, Nowika P, Shaw M, et al.: Long-term results of an obesity program in an ethnically diverse pediatric population. Pediatrics 2011; 127: 402–10. CrossRef MEDLINE PubMed Central|
|29.||Stark LJ, Spear S, Boles R, et al.: A pilot randomized controlled trial of a clinic and home-based behavioral intervention to decrease obesity in preschoolers. Obesity 2011; 19: 134–41. CrossRef MEDLINE|
|30.||Vos RC, Huisman SD, Houdijk ECAM, Pijl H, Wit JM: The effect of family-based multidisciplinary cognitive behavioral treatment on health-related quality of life in childhood obesity. Qual Life Res 2011; doi: 10.1007/s11136–011–0079–1 (last accessed on 27 January 2014). CrossRef MEDLINE|
|31.||Kromeyer-Hauschild K, Wabitsch M, Geller F, et al.: Perzentile für den Body Mass Index für das Kindes- und Jugendalter unter Heranziehung verschiedener deutscher Stichproben. Monatsschr Kinderheilkd 2001; 149: 807–18. CrossRef|
|32.||Max Rubner-Institut, Bundesforschungsinstitut für Ernährung und Lebensmittel: Nationale Verzehrsstudie II, Ergebnisbericht Teil 1, 2008; www.mri.bund.de/Nationale Verzehrstudie (last accessed on 24 March 2014).|
|33.||Ho M, Garnett SP, Baur LA, et al: Impact of dietary and exercise interventions on weight change and metabolic outcomes in obese children and adolescents: a systematic review and meta-analysis of randomized trials. JAMA Pediatr 2013; 167: 759–68. CrossRef MEDLINE|
|34.||Kaitosaari T, Rönnemaa T, Raitahari O, et al.: Low-saturated fat dietary counseling starting in infancy improves insulin sensitivity in 9-year-old healthy children: the special turku coronary risk factor intervention project for children (STRIP) study. Diabetes Care 2006; 29: 781–5. CrossRef MEDLINE|
|35.||Walpole B, Dettmer E, Morrongiello BA, McCrindle BW, Hamilton J: Motivational interviewing to enhance self-efficacy and promote weight loss in overweight and obese adolescents: a randomized controlled trial. J Pediatr Psychol 2013; DOI: 10.1093/jpepsy/jsto023 (last accessed on 27 January 2014). CrossRef MEDLINE|
|36.||Naukkarinen J, Rissanen A, Kaprio J, Pietläinen KH: Causes and consequences of obesity: the contribution of recent twin studies. Int J Obes 2012; 36: 1017–24. CrossRef MEDLINE|
|37.||Puhl RM, Heuer CA: The stigma of obesity: A review and update. Obesity 2009; 17: 941–64. CrossRef MEDLINE|
|38.||Hilbert A, Braehler E, Haeuser W, Zenger M: Weight bias internalization, core self-evaluation, and health in overweight and obese persons. Obesity 2014; 22: 79–85. CrossRef MEDLINE|
|39.||Crow S, Eisenberg ME, Story M, Neumark-Sztainer D: Psychosocial and behavioral correlates of dieting among overweight and non-overweight adolescents. J Adolesc Health 2006; 38: 569–74. CrossRef MEDLINE|
|40.||Neumark-Sztainer DR, Wall MM, Haines JI, Story MT, Sherwood NE, van den Berg PA: Shared risk and protective factors for overweight and disordered eating in adolescents. Am J Prev Med 2007; 33: 359–69. CrossRef MEDLINE|
|e1.||Onis M de, Onyango AW, Borghi L, Siryam A, Nishida C, Siekmann J: Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organ 2007; 85: 660–7. CrossRef PubMed Central|
|e2.||Schulz KF, Altman DG, Moher D: CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. BMJ 2010; 340: c332. CrossRef MEDLINE PubMed Central|
|e3.||Higgins JPT, Green S: Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0 (updated March 2011). The Cochrane Collaboration 2011. Online-Publikation: www.cochrane-handbook.org (last accessed on 6 August 2014).|
|e4.||Arauz Boudreau AD, Kurowski DS, Gonzalez WI, Dimond MA, Oreskovic NM: Latino families, primary care, and childhood obesity: a randomized controlled trial. Am J Prev Med 2013; 44: 247–57. MEDLINE|
|e5.||Berkowitz RI, Wadden TA, Gehrman CA, et al.: Meal replacements in the treatment of adolescent obesity: a randomized controlled trial. Obesity 2011; 19: 1193–9. CrossRef MEDLINE PubMed Central|
|e6.||Boutelle KN, Cafri G, Crow SJ: Parent-only treatment for childhood obesity: a randomized controlled trial. Obesity 2011; 19: 574–80. CrossRef MEDLINE PubMed Central|
|e7.||Davis McGrath A, Sampilo M, Steiger Gallagher K, Landrum Y, Malone B: Treating rural pediatric obesity through telemedicine: outcomes from a small randomized controlled trial. J Pediatr Psychol 2013; DOI: 10.1093/jpepsy/jst005. CrossRef MEDLINE|
|e8.||Duggins M, Cherven P, Carrithers J, Messamore J, Harvey A: Impact of family YMCA membership on childhood obesity: a randomized controlled effectiveness trial. J Am Board Fam Med 2010; 23: 323–33. CrossRef MEDLINE|
|e9.||Ebbeling CB, Feldman HA, Chomiz VR, et al.: A randomized trial of sugar-sweetened beverages and adolescent body weight. N Engl J Med 2012; 367: 1407–16. CrossRef MEDLINE PubMed Central|
|e10.||Johnston CA, Tyler C, Fullerton G, et al.: Effects of a school-based weight maintenance program for Mexican-American children: results at 2 years. Obesity 2010; 18: 542–7. CrossRef MEDLINE|
|e11.||Kalarchian MA, Levine MD, Arslanian SA, et al.: Family-based treatment of severe pediatric obesity: randomized controlled trial. Pediatrics 2009; 124: 1060–8. CrossRef MEDLINE PubMed Central|
|e12.||Kirk S, Brehm B, Saelens BE, et al.: Role of carbohydrate modification in weight management among obese children: a randomized clinical trial. J Pediatr 2012; 161: 320–7. CrossRef MEDLINE PubMed Central|
|e13.||Krebs NF, Gao D, Gralla J, Collins JS, Johnson SL: Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severly obese adolescents. J Pediatr 2010; 157: 252–8. CrossRef MEDLINE PubMed Central|
|e14.||Lloyd-Richardson EE, Jelalian E, Sato AF, Hart CN, Mehlenbeck R, Wing RR: Two-year follow-up of an adolescent behavioral weight control intervention. Pediatrics 2012; 130: e281–8. CrossRef MEDLINE PubMed Central|
|e15.||Naar-King S, Ellis D, Kolmodin K, et al.: A randomized pilot study of multisystemic therapy targeting obesity in African-American adolescents. J Adolesc Health 2009; 45: 417–9. CrossRef MEDLINE|
|e16.||O’Connor TM, Hilmers A, Watson K, Baranowski T, Giardino AP: Feasibility of an obesity intervention for pediatric primary care targeting parenting and children: Helping HAND. Child Care Health Dev 2013; 39: 141–9. CrossRef MEDLINE|
|e17.||Pbert L, Druker S, Gapinski MA, et al.: A school nurse-delivered intervention for overweight and obese adolescents. J Sch Health 2013; 83: 182–93. CrossRef MEDLINE PubMed Central|
|e18.||Taveras EM, Gortmaker SL, Hohman KH, et al.: Randomized controlled trial to improve primary care to prevent and manage childhood obesity: the High Five for Kids study. Arch Pediatr Adolesc Med 2011; 165: 714–22. CrossRef MEDLINE PubMed Central|
|e19.||Wake M, Baur L, Gerner B, et al.: Outcomes and costs of primary care surveillance and intervention for overweight or obese children: the LEAP 2 randomized controlled trial. BMJ 2009; 339: b3308. CrossRef MEDLINE PubMed Central|
|e20.||West F, Sanders MR, Cleghorn GJ, Davies PS: Randomised clinical trial of a family-based lifestyle intervention for childhood obesity involving parents as the exclusive agents of change. Behav Res Ther 2010; 48: 1170–9. CrossRef MEDLINE|
|e21.||Coppins DF, Margetts BM, Fa JL, Brown M, Garrett F, Huelin S: Effectiveness of a multi-disciplinary family-based programme for treating childhood obesity (the Family Project). Eur J Clin Nutr 2011; 65: 903–9. CrossRef MEDLINE|
|e22.||Sacher PM, Kolotourou M, Chadwick PM, et al.: Randomized controlled trial of the MEND program: a family-based community intervention for childhood obesity. Obesity 2010; 18 (Suppl 1): 102–4. CrossRef MEDLINE|
|e23.||Demol S, Yackobovic-Gavan M, Shalitin S, Nagelberg N, Gillon-Keren M, Phillip M: Low-carbohydrate (low & high-fat) versus high-carbohydrate low-fat diets in the treatment of obesity in adolescents. Acta Pediatr 2009; 98: 346–51. MEDLINE|
|e24.||Shalitin S, Ashkenazi-Hoffnung L, Yackobovitch-Gavan M, et al.: Effects of a twelve-week randomized intervention of exercise and/or diet on weight loss and weight maintenance, and other metabolic parameters in obese preadolescent children. Horm Res 2009; 72: 287–301.|
|e25.||Iannuzzi A, Licenziati MR, Vacca M, et al.: Comparison of two diets of varying glycemic index on carotid subclinical atherosclerosis in obese children. Heart Vessels 2009; 24: 419–24. CrossRef MEDLINE|
|e26.||Parillo M, Licenziati MR, Vacca M, de Marco D, Iannuzzi A: Metabolic changes after a hypocaloric, low-glycemic-index diet in obese children. J Endocrinol Invest 2012; 35: 629–33. MEDLINE|
|e27.||Hystad HT, Steinsbekk S, Odegard R, Wichstrom L, Gudbrandsen OA: A randomized study on the effectiveness of therapist-led v. self-help parental intervention for treating childhood obesity. BJN 2013; 110: 1143–50. CrossRef MEDLINE|
|e28.||Tjonna AE, Stolen TO, Bye A, et al.: Aerobic interval training reduces cardiovascular risk factors more than a multitreatment approach in overweight adolescents. Clin Sci 2009; 116: 317–26. CrossRef MEDLINE|
|e29.||De Piano A, de Mello MT, Sanches Pde L, et al.: Long-term effects of aerobic plus resistance training on the adipokines and neuropeptides in a nonalcoholic fatty liver disease obese adolescents. Eur J Gastroenterol Hepatol 2012; 24: 1313–24. MEDLINE|
|e30.||Weigel C, Kokocinski K, Lederer P, Dötsch J, Rascher W, Knerr I: Childhood obesity: concept, feasibility, and interim results of a local group-based long-term treatment program. J Nutr Educ Behav 2008; 40: 369–73. CrossRef MEDLINE|
|e31.||Partsalaki I, Karvela A, Spiliotis BE: Metabolic impact of a ketogenic diet compared to a hypocaloric diet in obese children and adolescents. J Pediatr Endocrinol Metab 2012; 25: 697–704. MEDLINE|
|e32.||Kelishadi R, Zemel MB, Hashemipour M, Hosseini M, Mohammadifard N, Poursafa P: Can a dairy-rich diet be effective in long-term weight control of young children? J Am Coll Nutr 2009; 28: 601–10. CrossRef MEDLINE|
|e33.||Wafa SW, Talib RA, Hamzaid NH, et al.: Randomized controlled trial of a good practice approach to treatment of childhood obesity in Malaysia: Malaysian Childhood Obesity Treatment Trial (MASCOT). Int J Pediatr Obes 2011; 6: e62–9. MEDLINE|
|e34.||Waling M, Lind T, Hernell O, Larsson C: A one-year intervention has modest effects on energy and macronutrient intakes of overweight and obese Swedish children. J Nutr 2010; 140: 1793–8. CrossRef MEDLINE|
|e35.||Lison JF, Real-Montes JM, Torro I, et al.: Exercise intervention in childhood obesity: a randomized controlled trial comparing hospital—versus home home-based groups. Acad Pediatr 2012; 12: 319–25. MEDLINE|
|e36.||Shaw KA, Gennat HC, O’Rourke P, Del Mar C: Exercise for overweight or obesity (review). Cochrane Database Syst Rev 2006, 4: CD003817. MEDLINE|