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Whitlock EP, O'Connor EA, Williams SB, et al. Effectiveness of Weight Management Programs in Children and Adolescents. Rockville (MD): Agency for Healthcare Research and Quality (US); 2008 Sep. (Evidence Reports/Technology Assessments, No. 170.)

  • This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

Executive Summary

Introduction

Childhood and adolescent obesity has increased dramatically during the past 30 years and now represents one of the most pressing national and international public health priorities. During the early 1970s, 3 to 6 percent of American children and adolescents were obese. By 2004, this number had increased five fold to 16 to 18 percent of all US 6 to 19 year olds. This increase is especially troubling as obese children and adolescents have a greater risk for adult obesity, with its attendant health risks, and may experience obesity-related health conditions before adulthood, including type 2 diabetes mellitus, fatty liver disease, and elevated cardiovascular risk factors. Severe obesity in children and adolescents can be associated with severe health consequences and dire impacts on quality of life.

The true toll of childhood obesity must be calculated across the lifespan since it often continues into adulthood. Thus, an important step to preventing adult obesity and its related health consequences is effectively treating childhood obesity. To this end, we conducted this systematic review to determine which treatments could effectively address child and adolescent obesity and overweight, including behavioral, pharmacological, and surgical treatment options.

Methods

Key Questions

In conjunction with a Technical Expert Panel, we developed a set of five key research questions to evaluate the effectiveness and safety of behavioral, pharmacological, and surgical treatments for obese and overweight children and adolescents who were 2 to 18 years old. These research questions addressed various measures of the health impact of treatments to reduce or stabilize weight, including: short-term impacts on weight control (6 to12 months after enrolling in treatment); maintenance of weight changes in the medium-term (between 1 to 5 years after enrollment) or longer term (5 or more years after enrollment); adverse effects of treatment (immediate and over time); beneficial effects of treatment, aside from weight control or weight loss; and treatment components or other factors that influence the effectiveness of treatments.

Literature Searches

In 2006, the National Institute for Health and Clinical Excellence (NICE) published a comprehensive report based on a good-quality systematic review of obesity in adults and children including literature published through December, 2005. Relevant portions of this report served as a basis for our literature search, supplemented by another good-quality review of pharmacological treatments. We also conducted update searches in Ovid MEDLINE®, PsycINFO, Database of Abstracts of Reviews of Effects, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Education Resources Information Center from 2005 (2003 for pharmacological treatments) through December 11, 2007. We supplemented these literature searches (and use of existing systematic reviews) by evaluating citations from several other good-quality reviews of childhood obesity treatment, suggestions from experts, and reviewing reference lists of included trials.

We searched for trials that used a control group and evaluated behavioral and/or pharmacological treatments for weight reduction or stabilization in overweight and obese children who were 2 to 18 years old. Since we could not find any surgical trials or studies that used a control group, we searched for systematically selected case series of children or adolescents undergoing bariatric surgical treatment to determine the immediate and longer-term effectiveness and harms of different types of bariatric surgeries. We also searched for, but did not find, large observational studies to consider adverse events related to behavioral, pharmacological, and surgical weight reduction treatments.

Literature Review and Data Abstraction

Two investigators independently reviewed 2355 abstracts and 338 articles against pre-specified inclusion/exclusion criteria for each key question. Discrepancies were resolved by consensus. We required that studies be designed to promote weight management and reported weight outcomes a minimum of 6 months after treatment began, although we included immediate harms when reported. We excluded studies of children with idiosyncratic weight management issues, such as genetic conditions that affect weight or eating disorders. One pharmacological agent (mazindol) and one type of bariatric surgery (jejunal-ileal bypass) were excluded because they are no longer used. Behavioral intervention trials were required to include a minimal or no-treatment arm to establish absolute effectiveness. For evaluating specific treatment components, however, we also included comparative effectiveness trials to help clarify how specific components affect overall treatment. Trials of pharmacological treatment were required to include a pill placebo control condition. Most trials also included a behavioral intervention for both active and placebo groups. All systematically selected surgical case series were permitted. For all included articles, key elements regarding patient characteristics, treatment components, weight-related outcomes, adverse treatment effects, treatment effects on co-morbidities, and elements related to study design and execution were abstracted into standard evidence tables. For behavioral intervention trials, treatment intensity (hours of contact) was categorized as very low (less than 10 hours), low (10 to 25 hours), medium (26 to 75 hours), or high (over 75 hours). Two investigators quality rated articles using design-specific criteria, with discrepancies resolved by consensus. Articles rated poor quality were excluded, except in the case of bariatric surgeries where, due to very limited data, we retained all surgical case series.

Literature Synthesis

Data were synthesized using quantitative methods, when possible. For most questions, however, we relied on qualitative synthesis due to significant heterogeneity in setting, age range, intervention approach, weight outcome reported, and timing of outcome. We modeled typical cases to more clearly describe the magnitude of weight change in pounds. In these cases, we used growth charts published by the Centers for Disease Control and Prevention to estimate average height for the average age of the participants in a trial, and then converted body mass index (BMI) and measures of relative weight (such as percentile scores) to estimated average weight in pounds, based on average height.

Results

Behavioral Interventions

We identified 18 fair- or good-quality trials of behavioral weight management interventions in a total of 1794 obese children and adolescents aged 5 to 18 years. All incorporated a minimal- or no-treatment control group. These trials were conducted in school settings (n=5 studies), specialty health care settings (n=5), primary care (n=2), residential treatment (n=1), child health/sports center (n=1), and the internet (n=1) with three trials conducted in unspecified settings. Behavioral weight management trials varied in other important ways, such as age of participants, intensity and length of the intervention, baseline weight, and treatment approach (e.g., approach to changing diet and physical activity, involvement of the family, role of behavioral management). We also evaluated 14 supplementary trials that did not meet our primary inclusion criteria, but were applicable to some specific key questions. Two of these reported only very short-term (<6-month) outcomes, but were relevant to the question of adverse effects. The remaining 12 all compared two intervention approaches to each other, rather than including a control group, but were relevant for assessing the importance of specific intervention components.

What are the short-term outcomes for behavioral interventions? Sixteen trials reported differences in some measure of weight immediately or within several months after treatment (6 to 12 months after enrollment); these trials enrolled children and adolescents aged 5 to 18 years whose BMI ranged from 20–24 (in trials of children 12 and younger) to 31–35 (in trials of adolescents) on average; these generally represented BMI percentiles above the 97th percentile. Behavioral interventions in either schools or specialty health care settings produced modest weight changes, reflecting weight loss as well as weight gain prevention. Most participants remained at or above the 95th percentile after completing the intervention. Intervention effects varied by treatment intensity and setting. In school settings, intervention trials that were mostly of medium intensity reported 0.4 to 2.07 kg/m2 difference in mean BMI change from baseline between a total of 191 treated and 247 control-group participants aged 6–14 years, with a pooled estimate of -0.82 kg/m2 (CI: -0.46, -1.18) lower BMI in those treated. For an 8-year old boy or girl, this would translate to about a three pound difference (assuming growth of two inches or less) and about a four pound difference for a 12 year old boy or girl under the same growth assumptions. In specialty health care settings, medium-to-high intensity intervention trials reported between 1.9 to 3.3 kg/m2 difference in mean BMI change between a total of 299 treated and 126 control-group participants aged 6 to16 years. For an 8-year old boy or girl, the largest achieved BMI difference (3.3 kg/m2) would translate to about 12 to 13 pounds difference, assuming two inches of growth, and about 16.6 to 17.8 pounds difference for a 12-year old boy or girl under the same growth assumptions. For girls aged 16 years, assuming 2 inches of growth, this BMI difference would translate to about 20 pounds, while the difference would be between 22 and 23 pounds for boys aged 16 with two inches of growth. In the most intensive intervention, children and adolescents in a 10-month residential program dropped from 75 percent overweight to 25 percent overweight, compared with a slight increase in overweight in children and adolescents who were on the waiting list for this program.

How well are weight changes maintained after behavioral interventions? Five trials (three in specialty health care, one in schools, one in primary care) reported medium-term weight outcomes, 1 to 5 years since beginning the intervention. Four of these trials suggested modest differences between a total of 632 treated and control patients aged 5 to 19 years after 1 to 5 years. Three of these (one in specialty health care, one in schools, one in primary care) also reported short-term outcomes, so we could evaluate whether short-term changes were maintained. In two of three trials, short-term benefits were largely maintained 12 months later. The third study in primary care that did not maintain short-term benefits was a very low intensity (4 hours), short-duration (3 months) intervention with initially very small intervention effects. Limited evidence suggests that programs providing a lower-intensity intervention targeting maintenance after the end of primary treatment allows greater maintenance of weight loss than programs with little or no maintenance support.

Are behavioral interventions harmful to participants? We found no evidence that behavioral interventions are harmful for participants. Most studies did not report on harms, however, and those that did could address only short-term harms due to length of followup. Based on this limited evidence, studies documented no adverse effects on growth, eating disorder pathology, or mental health, and little risk of exercise-induced injuries among obese children participating in exercise programs.

Do behavioral interventions have positive effects besides weight loss? Behavioral interventions can have a number of positive effects aside from changes in weight. These include reducing adiposity, improving cardiovascular and diabetes risk factors, and increasing physical fitness. Children and adolescents participating in behavioral intervention programs, particularly those that produce greater effects on BMI (such as those in specialty healthcare settings), may also see reduced adiposity. Increased physical fitness was less commonly measured, but was improved, particularly if the treatment involved organized exercise sessions. While some studies showed an impact on a range of risk factors, results were mixed and reporting was limited. Participants in behavioral intervention programs were less obese than in pharmacological or surgical treatments, and thus may have been less likely to have elevated cardiovascular or diabetes risk factors.

What components make a behavioral intervention successful? Because the trials of behavioral interventions showed so much variability, we could not draw any firm conclusions about the importance of specific treatment components. Brief synopses of treatment components for the effective behavioral intervention programs are shown in Table 7 (Chapter 3). We specifically examined three specific factors thought to be related to treatment success: provision of organized physical activity sessions as part of intervention; parental involvement for younger children; and utilization of behavioral management principles. Training in behavioral management techniques was commonly employed in these trials and may improve the likelihood of success. Over half of behavioral intervention trials provided physical activity sessions, and most of these were successful in changing weight or adiposity measures. Parent involvement is clearly important in younger children. The benefit of including parents in interventions targeted at adolescents, however, remains less clear. A primary factor in the effectiveness of interventions reviewed here was their intensity and setting: the greatest treatment effects were seen in residential treatment and in high-intensity interventions in specialty health care treatment settings; more modest treatment effects from primarily medium-intensity interventions were seen in school settings; and little or no treatment effects came from the few studies conducted in very low intensity primary care or over the internet. Other patient factors (age of children, degree of overweight or obesity, ethnicity/nationality, socioeconomic status) that could affect treatment success could not be evaluated.

Table 7. Effective behavioral interventions for overweight or obesity.

Table 7

Effective behavioral interventions for overweight or obesity.

Pharmacological Plus Behavioral Intervention

We found seven fair-to-good quality trials evaluating a pharmacological agent taken over six to twelve months along with behavioral interventions to treat obesity in a total of 1,294 obese adolescents. At baseline, participants met adult criteria for obesity, with mean entry BMI typically between 35 to 38 kg/m2. All trials provided behavioral interventions for the adolescents in both treatment arms. All trials involved adolescents age 12 and older, were double-blind, and included a pill placebo control group. Five trials in a total of 715 obese adolescents examined sibutramine and two in a total of 579 examined orlistat. We also found two small trials testing the weight effects of taking the diabetes medication, metformin, for 6 to 12 months in a total of 60 obese children and adolescents with evidence of insulin resistance or hyperinsulinemia. Those reports are not directly applicable to the general population of obese adolescents.

What are the short-term outcomes for pharmacological plus behavioral interventions compared with behavioral interventions alone? Almost all the sibutramine trials found group differences in BMI change. After 6 to 12 months, adolescents treated with sibutramine plus a behavioral intervention reduced their BMI by 1.6 to 2.7 kg/m2 more than those in the placebo plus behavioral intervention groups. Weight loss with orlistat was somewhat less: average BMI was 0.5 to 0.85 kg/m2 lower after 6 to 12 months in the group taking orlistat plus behavioral intervention than in the placebo plus behavioral intervention group. In the trials of metformin, those taking metformin reduced their BMI by 1.3 to 1.4 kg/m2 more than those taking the placebo.

How well are weight changes maintained after pharmacological treatments? No trials assessed maintenance of weight loss after the end of six or twelve months of treatment with sibutramine, orlistat, or metformin.

Are pharmacological treatments harmful to participants? Although no differences were reported in overall adverse events, serious adverse events, or discontinuation due to adverse events, adolescents taking sibutramine were more likely to develop small increases in heart rate and, in some cases, in blood pressure. Among orlistat users, mild-to-moderate gastrointestinal side effects, such as abdominal pain, oily spotting, or fecal urgency, occurred commonly (in 20 to 30 percent), with fecal incontinence reported in 9 percent of adolescents taking orlistat, compared with 1 percent of placebo participants. Limited evidence suggests no impact on growth for either medication. Neither trial of metformin in children and adolescents at risk for diabetes reported any serious adverse events, but these were very small studies.

Do pharmacological treatments have positive effects besides weight loss? Most studies suggested that both sibutramine and orlistat patients had greater reductions in adiposity than the placebo groups. Few other differences in cardiovascular or diabetes risk factors were found in those taking either medication, compared with placebo, except for reported improvements in HDL cholesterol, triglycerides, and insulin resistance/sensitivity among adolescents taking sibutramine in the single largest study. Similarly, in the single large study of orlistat, patients treated with orlistat had a small mean reduction in diastolic blood pressure. Both metformin trials reported improvements in fasting glucose and insulin measures.

What components make pharmacological treatments successful? We found insufficient data on effective pharmacological plus behavioral interventions to describe which components were most effective. Using proven behavioral treatments in conjunction with effective pharmacological agents, and ensuring their delivery, could be an important improvement.

Surgical Treatment

We identified 18 case series reporting on weight change, complications, and other outcomes from weight loss surgical interventions in a total of 612 morbidly obese adolescents, most of whom had failed previous weight management approaches. Where reported, 23 to 62 percent had one or more co-morbidities such as hypertension, diabetes, and dyslipidemia. Six of the studies explored the safety and efficacy of laparoscopic adjustable gastric banding (LAGB) and the remaining focused on gastric bypass procedures. The average ages for surgical patients in these studies ranged from 15 to 18 years. Mean baseline BMI was generally between 43 and 48 kg/m2 in LAGB studies and in the high 40s to mid 50s in the gastric bypass studies. Results must be interpreted with caution, however, because loss to followup, incomplete reporting, and small samples limits our confidence in the generalizability of these results.

What are the short-term outcomes for surgical treatment? Morbidly obese adolescents undergoing laparoscopic adjustable gastric banding experienced an average BMI decline of 5.0 to 8.1 kg/m2 six months after surgery, and a 9.4 to 10.2 kg/m2 decline one year after surgery. Bypass procedures showed somewhat greater weight loss at one year, with average BMI reductions in the 15 to 20 kg/m2 range.

How well are weight changes maintained after surgical treatments? Surgical treatments for obese adolescents have only been performed in recent years. In general, patients tend to lose the most weight at around 12 to18 months, after which their weight loss generally stabilizes. While we have only limited data on long-term outcomes, and insufficient data on all individuals, most patients seem to maintain their maximal weight loss after gastric banding (or experience a minimal amount of regain) for two to three years after surgery. One small study in 25 individuals after gastric banding found that BMI decreases were generally maintained 5 years after surgery. While we were only able to find very limited data on Roux-en-Y gastric bypass, based on 33 adolescents, BMI reductions were maintained at 5 years, with some regain suggested by 10 to 14 years. While there are clearly individuals who experience treatment failures, absolute rates for success or failure cannot be estimated with current data.

Are surgical treatments harmful to participants? Roughly 10 to 15 percent of adolescents undergoing laparoscopic adjustable banding require additional surgery for repositioning or removal of the band, but no serious adverse events or deaths were reported. Roux-en-Y gastric bypass is a more invasive procedure and, not surprisingly, appears to have higher rates of adverse effects. Serious adverse effects (involving threat to life or major organ system failures, but no deaths) occurred in approximately 5 percent of patients while in the hospital. In another study, 25 to 39 percent experienced non-life-threatening adverse events requiring additional treatment, special tests, endoscopy, or hospital readmission in the first year after surgery. Very limited numbers of cases and lack of long-term systematic follow-up limits our ability to assign absolute risks, including risk of death, over the longer term.

Do surgical treatments have positive effects besides weight loss? Not all studies measured or reported changes in co-morbidities after surgery. However, all cases of sleep apnea and most cases of reported asthma were resolved after surgery, with reported improvements in many with type II diabetes, hypertension, or dyslipidemia. More complete reporting would be very beneficial in assessing these potential health benefits that occur with weight loss after bariatric surgery in morbidly obese adolescents.

What components make surgical treatments successful? We have insufficient information to determine the relative benefits of different types of surgical approaches. Likewise, we found insufficient data to determine the impact of factors such as surgeon training or patient characteristics.

Conclusions

Evidence to support the effective management of obese children and adolescents is rapidly accumulating. We evaluated a total of 45 studies reporting weight management outcomes after behavioral interventions, pharmacological approaches combined with behavioral interventions, or bariatric surgeries in obese children and/or adolescents aged 5 to 18 years (See Table 13 Chapter 4). Behavioral interventions were applicable to obese children and adolescents over age 5 years, while pharmacological plus behavioral approaches were tested only in very obese adolescents aged 12 to 18 years. Bariatric surgeries were reserved primarily for morbidly obese adolescents aged 12 to 18 years who usually had co-morbidities and had failed conservative weight management strategies. Available studies did not evaluate effective treatment options for overweight (but not obese) children or adolescents, nor study those under aged 5 years.

Table 13. Main findings of weight reduction programs in children and adolescents.

Table 13

Main findings of weight reduction programs in children and adolescents.

Our review identified a progression of weight management treatment options, ranging from interventions with a smaller benefits and very low risk of adverse effects to treatments with both higher risk and higher weight loss potential. Behavioral interventions have been the most studied, with interventions conducted in schools, specialty health care, primary care, and other settings. These interventions have small-to-moderate impacts on weight, but minimal to non-existent risks. More intensive interventions, in terms of contact hours, appear to have larger treatment effects. Effective behavioral interventions generally addressed dietary improvement, physical activity promotion, and usually involved behavioral management principles and/or treatments, such as teaching parents and/or children about goal-setting, relapse prevention, problem-solving, and managing the environment to encourage healthy lifestyle. Providing children with organized physical activity as part of the intervention may improve successful weight management. Programs variously involved parents or focused on the family, but particularly did so in younger children. More research is needed to pinpoint the most effective elements of comprehensive, multi-focus behavioral interventions, and whether these differ by age, degree of overweight, or other factors.

For more severely obese adolescents, there is limited data evaluating pharmacological plus behavioral interventions and bariatric surgeries. The weight impact of two pharmacological treatments (orlistat, sibutramine) combined with behavioral interventions in obese adolescents produced small to moderate degrees of weight loss, which were comparable to the weight loss from more intensive behavioral interventions alone. Maintenance effects after pharmacological treatments have ended have not been well-studied and both medications have side-effects to consider. Among the highly selected extremely obese adolescent candidates for bariatric surgeries, more substantial weight loss was achieved, with some reversal of comorbidities, particularly severe ones such as sleep apnea. However, since little is known about long-term risks, and there are short-term risks that vary by the type of surgery, candidates must be carefully evaluated first for any bariatric surgery and then for type of surgery.

The body of research we reviewed implicitly suggests an approach to treating overweight and obesity in children and adolescents which balances considerations of the degree of risk related to treatment choice with the degree of impact on weight in order to improve health. Thus, the most risky treatments (e.g. bariatric surgeries) have been studied in adolescents with comorbidities and severe obesity, even by adult standards. A similar staged approach to treatments has been recently recommended by the Expert Committee, a committee convened by the American Medical Association (AMA) and co-funded in collaboration with the Department of Health and Human Services' Health Resources and Services Administration (HRSA) and the CDC. This group has delineated consensus-based along with evidence-based approaches that range from simple preventive messages for younger children and those who are not overweight, to approaches increasing in intensity as the child grows older and/or more obese, and with more associated health problems. Behavioral intervention programs are seen as the best first line treatment for overweight and most obese children and adolescents. Our review found that they can be effective and are likely to be safe when delivered to obese children aged five years and older.

Knowledge development continues at a rapid pace in this arena, with publication of additional research and policy activities by others, including the US Preventive Services Task Force, expected in the near future.

While this report focuses on the effectiveness and benefits of treatments in children and adolescents who are already overweight or obese, the challenge of achieving significant weight loss (and the uncertainty as to how well any weight reduction can be maintained) reaffirms the importance of obesity prevention. Obesity prevention is a critical component of the full breadth of a public health approach to overweight and obesity among American children and adolescents. Preventive approaches address some of the factors discussed above and emphasize helping children and adolescents develop lifelong healthy habits to prevent the development of overweight or obesity during childhood and into adulthood. Obesity prevention should be conceptualized broadly to include ecological interventions as well as health promotion campaigns in schools, communities, and health care settings.

Recommendations for Future Research

While childhood overweight has been the focus of considerable research in recent years, longer-term followup is needed to confirm maintenance of treatment effects for all types of treatment, but for pharmacological and surgical treatments in particular. Longer term followup should also describe the rate and severity of longer-term adverse effects, particularly for more invasive treatments. Given the central role of behavioral treatments, much more research is needed in this area. Replication of behavioral treatment trials is needed to confirm the benefits of programs and estimate their likely effects in real-world settings. Finally, understanding important components of behavioral interventions is an ongoing need. More studies are needed in minority children and adolescents, as well as in younger children (5 years and under).

Cover of Effectiveness of Weight Management Programs in Children and Adolescents
Effectiveness of Weight Management Programs in Children and Adolescents.
Evidence Reports/Technology Assessments, No. 170.
Whitlock EP, O'Connor EA, Williams SB, et al.

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