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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.)

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Effectiveness of Weight Management Programs in Children and Adolescents.

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4Discussion

Summary of Review Findings

We evaluated 18 behavioral intervention trials conducted in a variety of settings in 1794 obese children and adolescents aged 5 to 18 years, seven trials of pharmacological treatments (sibutramine or orlistat) combined with behavioral interventions in very obese adolescents aged 12 to 18 years (and two trials of metformin in very obese high-risk adolescents), and 17 case series of surgical treatments in morbidly obese adolescents (with usable data primarily from 15 case series). As illustrated in Table 13, behavioral, pharmacological, and surgical treatments not only vary in terms of absolute weight reduction, but also in terms of potential adverse effects. While limited evidence also suggests that treatments that produce greater degrees of weight loss may also reduce comorbidities and cardiovascular risk factors, data covered in this report do not allow us to determine the precise level of weight loss required for these additional benefits.

The Expert Committee has delineated approaches that range from simple preventive messages aimed at younger children and those who are not overweight, to weight management approaches that increase in intensity as the child is more obese or has more weight-related health problems. Behavioral interventions are seen as a best first line treatment; our review found that they can be effective and are likely to be safe when delivered to children aged 5 and older who are obese. The research we reviewed is not inconsistent with this recently proposed model of a stepped-care approach to weight management treatments that increases intensity (and treatment-associated risk) according to degree of overweight (or obesity), age/maturation, health risks, and motivation.5, 11

While all included studies primarily addressed obese children and/or adolescents (above the 95th percentile for age-and sex-specific BMI measurement and, in many cases, meeting adult criteria for obesity), the degree of obesity varied by type of treatment. Pharmacological treatments addressed very obese adolescents (adult obesity Class II) and surgeries were tested only in extremely obese adolescents (adult obesity Class III). Comparing BMIs of study participants across treatment type is critical to understanding to which participants the results of treatment trials can be applied.

Considering the BMI levels of study participants, currently studied treatments can not be clearly applied to the entire population of overweight and obese children and adolescents. Overweight and obesity are about equally prevalent among children and adolescents in the general population,13 but almost all of the trials of behavioral interventions that we evaluated were comprised wholly or mostly of children and adolescents who were obese. Although these types of behavioral interventions should be appropriate for overweight children and adolescents as well, current studies do not clarify their use or impact. We do not know whether those who are overweight (but not obese) have as high a need for treatment nor whether they would respond similarly to weight management interventions. The adolescents in whom effective pharmacological treatments or surgeries have been studied are in the upper percentiles of the BMI range or meet criteria for Class II or III obesity in adults, and thus represent a small fraction of the 16 percent of girls aged 12 to 19 and the 18 percent of boys aged 12 to 19 that are obese. Recent data estimates that only 1 to 3 percent of 13 to 17-year-old girls and 3 to 5 percent of 13 to 17-year-old boys have BMIs that are at or above the 99th percentile for their age and sex,10 and, based on evidence, the use of more invasive treatments would be primarily limited to these adolescents. Clearly, a comprehensive evidence-based approach to addressing the childhood obesity epidemic will require additional treatment research on categories of overweight or obese children and adolescents that are understudied, as well as consideration of obesity prevention programs that address the entire population. We return to these themes later in the discussion.

Behavioral Interventions

Based on our review, there are effective behavioral interventions that can improve weight measures, at least over the short-term, in obese children and adolescents aged 5 to 18 years. We found no evidence addressing weight management approaches in overweight or obese children under 5 years old. Evidence-based treatments for obese children aged 5 to 12 years are limited to behavioral interventions (without pharmacological adjuncts).

Behavioral interventions for obese children and adolescents aged 5 to 18 years in either schools or in specialty health care settings can effectively produce short-term improvements in weight. Very limited evidence suggests that these improvements can be maintained (completely or somewhat) over the 12 months following the end of treatment. The amount of absolute or relative weight change associated with behavioral interventions in these settings is generally modest and varies by intervention intensity and setting.

In school setting interventions, trials reported 0.4 to 2.07 kg/m2 difference in mean BMI change between those that were treated and controls at 6 to 12 months, with a pooled estimate of -0.82 kg/m2 (CI: -1.18, -0.46) lower BMI in those treated. For an 8-year-old boy or girl, this BMI difference would translate to about a 3 pound difference (assuming growth of 2 inches or less), and for a 12-year old boy or girl this would translate to about a four pound difference under the same growth assumptions. In girls aged 16, this BMI difference would translate to between 4.5 and 5 pounds, depending on growth. For 16-year-old boys the difference would be between 5 and 6 pounds.

Interventions in specialty health care settings (such as pediatric obesity referral clinics) resulted in a 1.9 to 3.3 kg/m2 difference in mean BMI change 6–12 months following treatment, compared with controls. For an 8-year-old boy or girl, the largest BMI difference (3.3 kg/m2) would translate to about 12 to 13 pounds (with up to 2 inches of growth). For a 12-year old boy or girl this would translate to 16.6 to 17.75 pounds difference under the same growth assumptions. In girls aged 16, this BMI difference would translate to about 20 pounds, while for boys aged 16, the difference would be between 22 and 23 pounds for two inches of growth or less.

The intervention effects possible with behavioral interventions, particularly those in specialty health care settings, appear adequate to improve adiposity, as measured by significant reductions in skin fold thickness measures or bioelectric impedance. Effects on blood pressure, lipids, or blood glucose levels have not been as well reported in those undergoing exclusively behavioral interventions as they have been for those combining pharmacological treatments with behavioral approaches. Limited evidence suggests that reductions in these measurements do not routinely occur, but are possible with the larger treatment effects seen in effective specialty health care treatments. As illustrated in Table 13, however, children and adolescents included in behavioral interventions tended to be less obese than those in pharmacological or surgical treatment trials, which would make them less likely to have elevated cardiovascular or diabetes risk factors.

Psychological outcomes were assessed in several trials, suggesting that interventions potentially improve depression, eating disorder pathology, and shape concern. These results, however, are based on minimal data and should be considered tentative. One included trial examined self-esteem and found no differences in change in self-esteem (both groups improved). Data were also mixed in a recent review131 on self-esteem in overweight children and adolescents.

We found no evidence of adverse effects on growth, on eating disorder pathology, or on mental health. Effects on growth found in this review are consistent with data from several noncomparative studies, including one that followed 158 children for 10 years and found that weight loss was not related to growth in height in a multivariate model controlling for child age, sex, baseline height, baseline percent overweight, and midparent height.132 We found little risk of exercise-induced injuries from behavioral interventions. Although these findings are reassuring, they are limited by incomplete reporting, given that fewer than half of behavioral intervention trials in children and adolescents specifically reported on any potential adverse effects. Only four trials of adolescents and two trials with both children and adolescents (representing relatively few total participants, since most trials enrolled fewer than 100 participants) reported results for any single type of adverse event. None of these found any adverse effects of treatment. The data on potential adverse effects are also further limited for children under 12 years of age. Only two studies83, 84 reported potential harms in participants in this age group, indicating no adverse impact on height gains in 111 children at 1 year83 or on body satisfaction or appearance at 1 year in 163 children.84 One bone fracture was reported among 107 children under aged 12 years participating in supervised exercise.93, 94

Most treatment programs focused on supporting healthy lifestyle changes through establishing healthful eating habits and increasing regular physical activity. While some trials in adolescents had the explicit goal of weight reduction, trials with younger children generally aimed to reduce participants' relative level of overweight through limiting weight gain as the child grew. Many trials utilized behavioral management techniques, such as teaching parents and/or children about goal-setting, relapse prevention, problem-solving, and managing their environment to encourage healthy lifestyle. Teaching behavior management techniques and providing organized physical activity sessions seem to improve the chances of a program's success.

Physical activity is clearly an important factor in altering the balance between caloric intake and expenditure, and therefore has in important role to play in weight loss interventions. All but two interventions in the 18 main trials included either actual exercise sessions or instruction in behavioral management principles targeting exercise. It appears that organized exercise sessions increase the likelihood of treatment success, but this could not be determined conclusively since programs with organized exercise as also tended to be more intensive programs with considerably more hours of contact. Regardless of whether children and adolescents exercise under the supervision of interventionists or on their own time, improved physical fitness is likely beneficial even if it does not increase weight loss.133, 134

Observational data show a relationship between sedentary behavior, such as television and electronic games, and obesity in children.135137 Interventions targeting sedentary behavior have reduced weight gain in trials of obesity prevention.138 However, the relative importance of targeting sedentary behavior in treatment of obesity could not be determined from the primary trials included in this review. In addition, Epstein and colleagues conducted three studies139141 examining the relative benefits of encouraging obese participants to decrease sedentary behavior, increase physical activity, or both. Taken as a whole, these trials did not demonstrate that any of these three approaches were clearly superior. One trial139 found that focusing on sedentary behavior was more effective than focusing on increasing physical activity, but neither of these groups differed from the group that encouraged both approaches. Neither of the remaining two trials found that the approach to physical activity had an impact on the effectiveness of weight-loss interventions.

All programs targeting younger children involved parents, and since parents usually control most of younger children's food intake, the necessity of parental involvement is self-evident. However, since all of the trials in younger children included parents, we have no empirical basis for quantifying the importance of parental involvement in this age group. The few trials in adolescents that included parental involvement were effective. Since these interventions included many components, however, it was impossible to isolate the specific effect of parental involvement in interventions targeting adolescents.

It is difficult to determine how well the results of these trials would generalize to patients in real-world treatment settings. Several studies relied at least in part on media advertisements for recruitment, and may therefore have enrolled participants who are more motivated to lose weight than a typical obese young person. Trials that recruited via screening, actively seeking participants rather than relying on potential participants to contact them, saw only a minority of overweight or obese children actually participate in the research trial. For example, only 38 percent in Graf's study86, 142 and 32 percent in McCallum's trial78, 84 who met weight criteria actually enrolled in the trials. There may be unmeasured differences between children who did and children who did not participate that influence how well they respond to the intervention. Children and adolescents who participate may have higher levels of motivation, more free time, more concerned parents, more failed attempts at weight loss, or any number of factors that may moderate the effectiveness of the intervention.

Pharmacological Plus Behavioral Interventions

Pharmacological adjuncts to behavioral interventions have been studied only in obese adolescents aged 12 to 18 years that meet adult criteria for class II obesity (mean BMI of 35 to 40 kg/m2 at trial entry), but not in less obese adolescents or in children younger than 12. Treatments with pharmacological agents (sibutramine and orlistat) delivered in combination with behavioral interventions over 6 to 12 months have been studied, but longer term results after treatment discontinuation are not available in any of the pharmacological treatment trials. This is an important limitation in our overall knowledge about their beneficial effects. Two small trials in very obese adolescents at high risk for type 2 diabetes mellitus examined the impact of metformin on glucose tolerance, insulin sensitivity, and BMI. These results are preliminary and are not directly applicable to the general population of obese adolescents.

The most informative data on sibutramine comes from a large (n=498) multicenter trial testing 12 months of sibutramine plus a behavioral intervention, compared with the behavioral intervention plus placebo. Participants receiving 10 to15 mg per day of sibutramine treatment plus a behavioral intervention decreased their BMI 2.9 kg/m2 at the conclusion of treatment, corresponding to an average weight reduction of 6.5 kg (14 pounds). Trial participants receiving a behavioral intervention (plus placebo) reduced their BMI 0.3 kg/m2, which correspond to a weight gain of 1.9 kg (4.2 pounds). The weight reduction possible at 12 months with effective behavioral intervention in specialty health care is similar in magnitude to the benefits achieved with 12 months of sibutramine plus some level of behavioral intervention. Direct head-to-head comparisons would allow us to confirm this impression.

Available data do not allow us to clearly determine whether behavioral interventions that produce similar effects on BMI as sibutramine also produce similar effects on other potentially beneficial outcomes. In most of the sibutramine trials, waist circumference in those receiving sibutramine was significantly reduced, on average 7 to 8 cm compared with 2 to 3 cm reductions in controls. Significant improvements in HDL cholesterol, triglycerides, and glucose tolerance measures (serum insulin and HOMA) were reported in the sibutramine treatment group in the largest multicenter trial (n=498). Trial participants receiving sibutramine were consistently more likely to develop elevated heart rates than placebo-treated participants, but had similar rates of discontinuation due to this side effect. Systolic or diastolic blood pressure (or both) were significantly elevated in about half of trials. These differences, however, were small in magnitude and are of unknown clinical significance. Few other adverse effects with sibutramine treatment were noted, except for one report of increased constipation. Limited evidence suggests no adverse effects on growth or maturation. One trial testing only three months of sibutramine (10 mg/day) plus six months of a behavioral intervention (compared with placebo and a behavioral intervention) showed modest BMI reductions at 6 months (-0.8 and -1.4 kg/m2) in both arms favoring placebo, but these were not statistically significantly different. No adverse effects were reported.

The most informative data on orlistat come from a large multicenter trial (n=539) testing 12 months of orlistat (360 mg/day) treatment plus a behavioral intervention. Mean BMI in this trial was significantly different (-0.55 kg/m2) after treatment, compared with those receiving the behavioral intervention only (who increased their mean BMI 0.3 kg/m2). This difference reflected weight gain in both groups, which was relatively attenuated in the orlistat group. From these results, it appears that the behavioral intervention component of the orlistat trials was ineffective. This could reflect the freedom at each of the 32 centers to use its own approach to the behavioral intervention aspect of the trial with no assessment of delivery.99 Therefore, the quality or intensity of the behavioral interventions may have been lacking at some sites. Participants receiving orlistat significantly reduced their waist and hip circumference (2.7 and 1.5 cm respectively), compared with controls (0.9 and 0.1 cm reductions). Serious adverse effects were uncommon. However, mild-moderate gastrointestinal side effects (most commonly oily spotting, evacuation, abdominal pain, fecal urgency, or flatus with discharge) occurred in 20 to 30 percent of patients taking orlistat and 9 percent reported fecal incontinence. Few participants (2 percent) discontinued treatment due to these side effects, although 35 percent overall dropped out before the trial ended. The impact gastrointestinal effects would have on treatment adherences outside a trial setting is unclear. Orlistat treatment did not reduce vitamin A, D, or E levels or affect growth, bone mineral density, or sexual maturation.

Sibutramine appears to have a larger effect on weight than orlistat, although the two drugs have not been compared directly. Only orlistat has been approved for use in pediatric populations (aged 12 years or older) by the FDA. Both drugs have side effects that must be taken into account when considering treatment for an individual patient. While orlistat has a higher rate of adverse effects, the nature of these effects may be less clinically significant than those seen with sibutramine. Both drugs lack evidence of persistence of weight reduction after active treatment ends.

As with the interventions that were limited to behavioral approaches, these trials involving the addition of pharmacological agents may also be subject to limitations in how well they apply to real-world treatment. That is, adolescents participating in these trials may be more or less likely than the average overweight or obese adolescent to respond to the intervention provided. For example, they may have higher levels of motivation to lose weight and therefore do better than the average adolescent, or they may have a greater number of failed weight loss attempts, which may make them less likely to succeed than the typical overweight or obese teen in the community. The supports provided in a typical trial may also exceed those provided in a usual treatment setting.

Surgical Treatments

Some adolescents reach extremely high levels of obesity and experience substantial health problems due to increased weight. For morbidly obese adolescents with obesity-related health problems who have failed intensive efforts at medical management, surgery may offer a treatment of last resort. Case series of laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, and other bariatric surgery techniques have been reported in a relatively small number of severely obese adolescents. Surgical case series have been based primarily on retrospective medical chart reviews of patients who have received clinical care. Followup in these series can be incomplete and data collection inconsistent. Thus, both data on weight outcomes as well as other beneficial outcomes from surgery are quite limited. Adverse effect documentation may be somewhat better, particularly for serious adverse effects, since these would reflect issues requiring clinical diagnosis and/or treatment.

Although adolescents undergoing obesity surgery have generally been required to meet NIH criteria for surgery in obese adults (BMI greater than 40 kg/m2 or greater than 35 kg/m2 with co-morbidities), adolescents included in surgical series were much more severely obese (Table 11). Those undergoing gastric bypass and other bariatric surgeries requiring laparotomy were more severely obese than patients undergoing LAGB.

LAGB is logically the surgical treatment of choice in morbidly obese adolescents who are candidates for bariatric surgery, since it should be completely reversible and potentially less risky than other bariatric procedures. LAGB is done via laparoscopic rather than open surgery (laparotomy). Both absolute weight loss and risks related to the surgery, however, appear to be lower after laparoscopic adjustable gastric banding than after more invasive procedures, including gastric bypass procedures. In one LAGB series (n=53),111estimates of mean reduction in BMI at 6 months ranged from 5.0 to 8.1 kg/m2 in intention-to-treat and in complete case analyses respectively. We focus on intention-to-treat analyses as the more realistic measure of overall treatment efficacy. In two studies (n=69), estimates for mean BMI reduction at 12 months ranged from 9.4 to 10.1 kg/m2. Based on limited longer term followup from the same two studies.114, 115 BMI reductions somewhat reversed between one and three years after surgery (from 10.1 kg/m2 at 1 year to 8.2 kg/m2 at 2 years and from 9.4 kg/m2 at 1 year to 7.3 kg/m2 at 3 years). Little data are available to estimate the proportion achieving clinically significant thresholds of weight reduction after surgery or the proportion that fail bariatric surgeries. One small study115, 116, 130 (n=17) reported that three-quarters of patients at 12 months and 82 percent at 24 months achieved a BMI less than 35. Similarly, a single case series117, 129 of 50 patients reported that only 3/50 (6 percent) did not achieve at least 25 percent body weight loss at one-year post-surgery. No perioperative mortality or major morbidity after LABG has been reported. Limited data suggested 10 to 13 percent of adolescents undergoing LABG require reoperations for band repositioning or removal. Around 10 percent may also have nutrition-related complications (mild hair loss or iron deficiency). Other miscellaneous complications were rarely noted. Very little data are available on whether comorbidities resolved after surgery. It seems clear, however, that those with sleep apnea and probably weight-associated asthma experience resolution, given the degree of weight loss induced by surgery.

A greater reduction in BMI has been seen in adolescents undergoing Roux-en-Y gastric bypass (RYGB) or vertical banded gastroplasty (VBG) procedures. In one small case series120, 121 of 18 adolescents whose median preoperative weight was 147 kg, median percentage of body weight lost at 10 to 15 months was 23 percent. At 12 months after RYGB surgery (performed laparoscopically or requiring a laparotomy) in two studies (n=63 adolescents), mean reductions in BMI ranged from 15.5 to 20.7 kg/m2. Among 24 patients with ongoing followup,108 mean BMI appeared to be maintained at 5-year followup. Followup data beyond five years are very limited (less than 20 persons eligible and fewer with measured weights). Most studies that report data on followup longer than one year after surgery are uninformative due to averaging weight measurements taken from individuals at markedly different points of time after surgery (often over 10 years apart). Further, only small numbers of patients are eligible for longer term post-surgical followup, given the rarity of performing bariatric surgery in adolescents during this time period. Treatment failures, however, have been reported even among these limited data. In one series,112 two of 30 patients regained up to 50 percent of the weight lost within the first year. Five of 33 patients regained most or all of their weight 5 to 10 years after RYGB.108 In both of these cases, patients met NIH inclusion criteria for adults. In a large nationally representative study of inpatient data from 566 RYGB or gastroplasty surgeries in adolescents, no in-hospital deaths were recorded, but major complications occurred in 5.5 percent of patients (two-thirds of which were respiratory). Longer-term adverse events were not captured. Other data suggest, however, that complications occur in at least 30 percent of patients during the first year after open RYGB, and in at least 39 percent in the first 12 months after laparoscopically performed RYGB. After laparoscopically performed RYGB, severe complications (death or severed organ failure) were reported in 2/36 patients and 5/36 patients experienced reoperation, unanticipated intensive care unit admission, or hospital readmission for more than seven days. About one-quarter of patients (13/47) required some special test, treatment, endoscopy, or hospital readmission for seven days or less.

At five years after VBG surgery, three-quarters of patients achieved over 25 percent excess weight loss, although this estimate was lower (61 percent) at “last followup.” 119 This procedure is not currently in widespread use due to higher recidivism than other surgeries and the advent of gastric banding. Although biliopancreatic diversion surgeries (with or without duodenal switching) are not currently in widespread use, it is worth noting that significant harms, including long-term mortality, were reported in 4.4 percent and protein-calorie malnutrition in 16 percent of patients within one to 10 years after surgery.128 These data suggest this procedure may be too risky to be considered in obese adolescents.

Even more so than the children and adolescents participating in behaviorally based treatments (with pharmacological adjuncts or those without), adolescents receiving bariatric surgeries were a highly selected group of extremely obese primarily older adolescent patients (with average pre-surgical weights ranging from 284 to 297 pounds) that were often accrued over many years of practice. Many if not most had obesity-related co-morbidities. While bariatric surgeries may provide life-saving treatments for some morbidly obese adolescents, the very limited data currently available on treatment efficacy, along with the known short-term risks and unknown long-term implications of bariatric surgery, demand the utmost care and consideration before choosing these types of treatments and conducting prospective collection of long-term outcomes.45, 143

Long-term Maintenance

It is unfortunate, although not surprising, that evidence of treatment maintenance is quite limited in behavioral intervention trials and surgery studies, and nonexistent in trials of pharmacological treatments. Long-term outcomes are particularly important for surgical treatments, especially in younger adolescents, in whom continuing growth and maturation are complicating factors. The effects of mechanically restricting absorption or the size of the stomach in these children, and of potentially substantial weight loss, cannot be ascertained from the adult literature.

Although this review focused on controlled trials, we searched for additional evidence that may shed light on long-term effectiveness of behavioral intervention programs. An observational study of a behavioral intervention by Epstein and colleagues reported on 10-year followup of four comparative effectiveness treatment trials in children 6 to 12 years of age that were conducted between 1981 and 1986.144 It did not meet our inclusion criteria because it had no control group for comparison purposes, and it is unclear what proportion of the original participants provided 10-year followup data. Epstein and colleagues report that 30 percent of their participants were not obese at 10-year followup. It is difficult to determine, however, whether this is a higher rate of change than would be seen in a general population of obese children, many of whom likely seek assistance naturalistically in various forms. Freedman and colleagues' large scale observational study of children in Bogalusa, Louisiana27 found that 22.8 percent of 9 to 11 year olds who were at or above the 95th percentile were no longer obese an average of 16 years later, which is lower than the 30 percent found by Epstein and colleagues. On the other hand, a retrospective observational study from the UK found that 39.3 percent of obese 16-year-olds were no longer obese at age 30, which is a higher rate of remission than that reported by the Epstein study. Several differences between the populations and settings of these studies limit drawing definitive conclusions about whether children undergoing treatment programs are more or less likely to be obese at long-term follow-up. Limited as it is, the best evidence remains that described for KQ2 addressing maintenance effects after treatment, in which control groups were comparable to the treated participants and outcomes were measured consistently between the groups. Even longer-term followup of participants in these trials could be very informative.

Applicability to Vulnerable Populations

As discussed, research on treating obesity must be considered in terms of its applicability to the general population of obese children and adolescents and, in particular, those bearing the greatest burden due to higher prevalence of obesity. These vulnerable groups include racial and ethnic minorities13, 15 and those within lowest income groups,19 who disproportionately bear the brunt of the obesity epidemic.

Minority involvement in addressing the obesity epidemic will be essential, and as such, their involvement in obesity research is critical. Five71, 74, 75, 77, 89 of the behavioral intervention trials with short-term outcomes had 10 percent or more of the children and adolescents in their samples classified as Hispanic, including two trials that comprised only Mexican-American participants.71, 75 The remaining three reported 24.7 percent,74 15.9 percent,77 and 12.5 percent89 Hispanic samples. All of these, except the trial with the least-intensive intervention89 found that the intervention programs improved weight outcomes. The highest-intensity trial74 of these five reported that there were no differences in any outcome measure between ethnic groups. This, coupled with the fact that both of the trials with 100 percent Mexican-American participants were successful, indicates that behavioral interventions can have an impact in Hispanic young people. Two of the trials had more than 10 percent of their samples classified as Black,74, 76 one of which included 38.5 percent Black children. This trial successfully promoted weight loss74 and reported no ethnic differences on any outcomes. The other 89 did not improve weight loss outcomes, included 26.3 percent Black youth, and did not report on the impact of ethnicity on treatment outcome. None of the trials with maintenance outcomes reported more than minimal inclusion of Black or Hispanic children and adolescents.

We found no evidence to suggest that medication treatment is more or less effective in Black or Hispanic than in White youth. Black and Hispanic youth were present in the samples of most of the medication trials, although only three98, 99, 104 examined differential impact of treatment by ethnicity: large-scale trials of sibutramine,98 orlistat,99 and a small trial of metformin.104 None of these trials found that race had an effect on response to treatment. Data on minority youth in surgical case series were reported in only two trials,108, 111 which involved a total of nine Black and seven Hispanic youth between the two trials. No results were reported specifically on the minority youth in either study.

Little was reported about the socioeconomic status of participants in any of the studies. Given the lack of universal access to health care, however, programs delivered through health care settings could be out of reach of many. Public school programs, however, could be available to most if not all children.

Applicability to Real-world Settings

While behavioral interventions are all ostensibly applicable to real-world settings, three of the trials69, 71, 75 conducted in schools involved programs that would likely be truly feasible for schools to offer during school hours as alternative health and physical education classes without extensive financial investment. All three of these programs were conducted all or mostly during school hours, and could be included in a school curriculum with some additional resources to support teacher training and planning, the acquisition of materials, and consultation with experts such as dietitians and behavioral specialists. Research on dissemination of programs such as these would be extremely valuable.

Higher intensity programs that were conducted in specialty care settings may also be feasible for many health care settings, perhaps at little extra cost. It may be possible to adapt the detailed protocols developed for use in the trials included in this review. For example, the comprehensive and effective Bright Bodies weight management program developed by Savoye and colleagues,74 was facilitated by a registered dietitian or social worker and an exercise physiologist. A team of professionals in these or related fields would likely have the requisite training to conduct this type of program without extensive additional training. Third-party payment for these types of programs or indication of their cost-effectiveness would assist in their uptake in the real world.

Two of the behavioral intervention programs specifically addressed the use of very-low-intensity interventions (approximately four hours of total intervention time) that could be integrated into primary care.77, 78, 84 Only one of these improved short-term weight loss,77 and could be feasible for implementation in some primary care practices, if it is proven to be beneficial through replication. This program relied on bachelors-level support staff to provide adjunctive care via mail and phone counseling, thus relieving the primary care provider of some of the burden of conducting the intervention. Dissemination research would be needed to truly determine the wide-spread feasibility of this and other ostensibly feasible programs.

While pharmacological treatments have been studied in multi-site clinical trials, which enhances their applicability, treatment adherence outside of the trial setting and longer term weight impacts remain unclear. And, as recommended by experts, surgical treatments should probably be delivered in centers of excellence for bariatric surgery, with adaptation to the nutritional, psychological, and medical needs of adolescents.45

Contextual Issues

Factors Contributing to the Recent Increase in Childhood Obesity

While many experts have speculated on the causes of the recent increases in childhood obesity,145, 146 data are not available to conclusively determine causality. Evidence does support, however, a relationship between childhood obesity and several factors, such as overall physical activity, sedentary behaviors (e.g., watching television, playing video games, and spending time on computers), and intake of sweetened beverages.11 Children (ages 2 to 17) average 4.7 hours per day “screen time” (covering cluster of activities involving television and computer screens, such as TV viewing, DVDs/videotapes, video games, computer games, e-mail and other computer activities).147 Cross-sectional data show that higher prevalence of obesity is associated with more hours per day watching television.136, 137 Also, an obesity prevention program that reduced screen time by an average of almost ten hours per week also resulted in a BMI reduction of 0.45 kg/m2 in sample of 3rd and 4th grade school children.138 Environmental factors have likely reduced the amount of physical activity children get currently. For example, in 1969, 42 percent of children walked to or rode their bikes to school, while only 16 percent of children did so in 2001.148 Also, enrollment in physical education classed declined from 41.6 percent in 1991 to 28.4 percent in 2003 in high school students.149 Longitudinal and cross-sectional observational data have demonstrated that higher levels of physical activity tend to be associated with lower BMIs in children.136, 150 In one study, an increase in one hour/day of physical activity was associated with a BMI decrement of 0.22 kg/m2 in boys and 0.16 kg/m2 in girls after one year.150

Similarly, intake of sweetened beverages has also increased and appears to contribute to childhood obesity.11, 151153 Between the late 1970s and the late 1990s, average daily intake of sweetened beverages increased from 5 ounces to 12 ounces in 6 to 17 year-olds.153 BMI increases by an estimated 0.01 kg/m2 with every 100 grams of regular soda consumed daily in adolescent girls, but this is not true of other beverages.151 The odds of obesity increases by 60 percent with each additional serving of sugar-sweetened soda consumed in children.154

Preventing Childhood Obesity and Overweight

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, in order 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.

Calling for public health action at its broadest and most inclusive level, the Institute of Medicine (IOM) created a set of 10 integrated recommendations for families, schools, communities, the public sector, and the private sector to prevent the development of obesity in the majority of children and adolescents in the United States1 (see Table 14). In addition to their recommendations to parents for creating a home environment conducive to a healthy lifestyle, they recommend that schools provide regular physical activity and an environment that facilitates eating healthy foods, with the support of federal and state departments of education and health and professional organizations. The IOM recommends that local governments, private developers, and community groups work together to expand opportunities for physical activity through recreational facilities, parks, sidewalks, and urban planning that encourages alternative forms of transportation. The IOM recommends that the advertising and marketing industry develop and strictly adhere to guidelines that minimize the risk of obesity in children and adolescents, and that the Federal Trade Commission monitor compliance with these standards. Policymakers and other leaders would do well to consider evidence on the full range of programs that constitute a broad scale approach to childhood obesity.

Table 14. National public health priority recommendations from IOM for childhood and adolescent obesity prevention.

Table 14

National public health priority recommendations from IOM for childhood and adolescent obesity prevention.

To support the broad public health recommendations called for in the recent IOM report, international experts are engaged in ongoing activities, including summarizing available research to inform best strategies for health promotion and primary prevention of childhood obesity through policies and programs in healthcare and other community settings. The CDC is undertaking a series of reports on evidence to support obesity interventions in schools, community-settings, and health systems, which are made publicly available as they are completed.155 The CDC also provides statistics on the prevalence of childhood obesity by state and year, data from the School Health Policies and Programs Study and from the Youth Behavioral Risk Factor Surveillance System, and information about state and local programs.156 The National Institute for Clinical Excellence (NICE) in the United Kingdom made its comprehensive evidence-based clinical guideline on both obesity prevention and treatment in adults and children available in December, 2006.2 Other systematic reviewers have published reports recently examining the effectiveness of preventive interventions and factors associated with etiology and risks. The Robert Wood Johnson Foundation's Active Living by Design Program has sponsored considerable research that has supported a link between the built environment and physical activity. Reviews of the impact of urban planning and obesity have concluded that “(1) areas with mixed land use, greater residential and commercial densities, grid street networks, and sidewalks are associated with more walking, biking, and pubic transportation usage; and (2) children with access to parks, recreation facilities, and programs are more physically active than children without access”.157 Given the relatively small effects seen in most behavioral interventions, and the fact that more invasive interventions are only appropriate for a small portion of the population, prevention programs are likely to be the most effective agents in slowing the growth of childhood obesity.

Review Limitations

Limitations in the Body of Evidence

The quality of research on treating child and adolescent obesity has improved substantially since the 2003 Cochrane review and our 2005 review which both enumerated concerns about the childhood obesity treatment literature, specifically regarding behavioral interventions. These concerns included small sample sizes, high attrition (among other quality issues), less than ideal outcome measures, and highly heterogeneous treatment approaches.51 Most (15/18) of the behavioral interventions included in our review were published since the end of the search window for these prior reviews, including seven published in 2007 and three in 2006. Several of the newly published trials have over 100 participants, although larger trials can be quite expensive. While retention remains somewhat problematic, eight of the 15 newer trials reported overall retention of 89 percent or higher. Outcome measurement has improved as well—almost all of the newer trials reported raw BMI scores or BMI SDS and all directly measured their participants rather than relying on self-report (though some did fill in missing data with self-report measures). A lingering quality issue, however, is that the blinding procedures for treatment allocation and outcomes assessment were often not described. And, research would be improved with more explicit reporting of intervention fidelity and of impacts on other outcomes (both harms and benefits, such as comorbidities), in addition to weight. Finally, while treatment trials remain quite heterogeneous, it is hoped that better reporting and growth in the research base will eventually allow determination of effective components of behavioral interventions.

While methods and reporting have improved, and the number of studies has increased, the large amount of heterogeneity in the behavioral intervention literature (e.g., populations, intervention intensity, settings, treatment components, types of outcomes assessed) makes providing summary measures of expected treatment effects still very difficult. Thus, our findings and meta-analysis should be interpreted with caution. While it appears that treatment settings were the major factor differentiating size of treatment effect, other factors such as treatment intensity and age also appear to be important and may have been inappropriately combined in our meta-analysis. Because change in BMI has a different meaning for children of different ages, it would have been preferable to analyze change in BMI SDS, which is adjusted for age and sex. However, many authors did not report BMI SDS, and because special software or look-up data are needed to calculate BMI SDS, it was not feasible to expect authors to provide this data upon request.

While larger trials of pharmacological treatments are quite recent (2005 and 2006), as are better quality surgical case series (2005 to 2007), the available treatment data for these approaches remains limited. There are only two weight-loss medications studied (sibutramine, orlistat), with few randomized trials overall, and only one large-scale trial of each of the medications. No trials were conducted among children age 11 years or younger, so no conclusions can be drawn regarding efficacy or safety for that age group. We found no data on long-term maintenance of treatment effect or safety. The longest treatment period studied was 12 months, and the only followup reported for either medication was 3 months after medication use terminated. Medication use may have either a positive or negative effect on long-term maintenance of weight changes, compared with exclusively behavioral approaches, so longer follow-up is very important. While we found sibutramine and orlistat each had one large-sample trial, these trials were not large enough to detect more rare but serious adverse effects. The high variability across trials in intensity and possibly of intervention fidelity for behavioral interventions hampered our ability to determine both the combined and independent effect of the medication.

Surgical case series are not considered to be strong evidence as these are non-comparative studies. Without a good understanding of the natural history of weight in severely obese children, it is difficult to determine if the case series are giving an accurate estimate of the effect of surgery compared with no treatment. Lack of prospective, research-designed data collection also limits the results.

The research on all types of obesity treatments remains limited for its focus on obese (or highly obese) children and adolescents. While focus on more obese adolescents is appropriate for pharmaceutical and surgical treatments, future researchers evaluating all three types of weight management approaches should address current limitations by ensuring that their studies enroll the range of obese (or overweight) children and adolescents who might benefit, and for whom the level of treatment-associated risk is appropriate. Future researchers should also address limitations in research on children under aged 6 and ensure that treatment studies enroll and evaluate race-specific effects among adequate numbers of racial and ethnic minority participants. Further data on long-term maintenance of treatment effects (benefits and harms), and better reporting of the effect of treatment on co-morbidities will address these important limitations in the currently available evidence.

Limitations in our Approach

We conducted comprehensive searches of multiple electronic databases (including those with dissertation abstracts), reviewed bibliographies, and contacted experts, but did not hand-search or otherwise review gray literature. We may not have located all relevant studies through this approach. We also did not formally assess for publication bias, given the heterogeneity of outcomes reported in included studies. Thus, it is possible that our review overestimates overweight treatment efficacy due to the “file drawer” problem whereby ineffective treatment studies are more likely to be unpublished. Finally, our review did not include all studies that others might consider relevant. We did not do a comprehensive assessment of comparative effectiveness trials, as our primary goal was to determine whether treatment worked and the size of the effects compared with no treatment. The comparative effectiveness literature was fairly extensive, and included considerable older work completed by Epstein and colleagues as well as other researchers, which represents the majority of research available for earlier reviews. We could not be confident that comparative effectiveness results would tell us about the overall effectiveness of either treatment approach tested because good, recent data could not be found on the natural history of childhood obesity. Also, there was a great deal of variability in the basic weight management approach and in the reporting of the programs, so we did not believe that effectiveness of individual components could be accurately isolated. After consultation with our Technical Expert Panel, we chose to limit our use of comparative effectiveness trials to further explore approaches (e.g., physical activity components, behavioral management techniques, and parent involvement) that seemed to be important components in those interventions that were shown to be effective when tested against minimally treated control groups.

Our examination of other beneficial outcomes was limited to studies that met our general inclusion criteria, including reporting some measure of weight change six months or more after the baseline assessment. Given the primary purpose of this review (focus on weight management) and with support of our Technical Expert Panel, we did not include trials that reported other beneficial outcomes without some measure of weight change, and therefore may have missed some reports of other beneficial outcomes.

We did not address the impact of population-based prevention programs on weight reduction in overweight or obese children. These programs are primarily targeted at preventing obesity, but since some children participating in these programs are already overweight or obese when they begin, it would be useful to know the degree to which overweight and obese children benefit. It would also be useful to know whether overweight and obese children suffer deleterious effects of such programs, such as increased dieting, increased teasing, or poorer self-esteem.

Emerging Issues/Next Steps

In order to have a real impact on childhood obesity, a broader approach to obesity care may be required within the health care system and in connecting the health care system with efforts in the broader community. Dietz and colleagues158 have proposed a model of care in which self-management by the patient or parent is considered central. The health care system supports self-management by making decision support tools available to office-based providers, teaching providers to help children and adolescents with excess weight and their families to make changes and access helpful resources, help increase patient confidence in their ability to make changes. Barlow and colleagues5 have recommended a complementary office-based system that relies on a network of health system resources (such as pediatric dietitians or behavioralists) and referral resources (including community resources and specialty treatment settings with access to a multidisciplinary team experienced with childhood obesity). Both groups recognize that health plans also have a role to play in changing the environment, particularly to support obesity prevention, through partnerships with schools and community organizations.158, 159

Given the importance of child and adolescent obesity worldwide, this is an extremely active area for ongoing research, for clinical and public health guideline development, and for development of policies that affect all aspects of society. Federal agencies and private foundations, such as the Robert Wood Johnson Foundation,160 have put very high priority on funding obesity research as well as disseminating findings once research is completed. Thus, this issue will require frequent revisiting for those intending to make policy and clinical decisions based on the most up-to-date thinking and evidence available.

We identified over 20 ongoing clinical studies that investigate the broad spectrum of issues related to obesity in children and adolescents.161 About half focus on adolescents (12 to 18 years) while the other half enroll children 7 to 11 years. The only trial focusing on the very young (3 to 5 years) is a primary prevention trial. Almost all of these studies include behavioral interventions to improve healthy diet and/or physical activity among already overweight or obese young people in order to reduce BMI or body fat. However, a few focus on environmental interventions such as integrating activities at home and in schools to reduce sugar-sweetened beverage consumption or on primary prevention through engaging children and caregivers in a home-based or community recreation center program to improve healthy eating and physical activity. A range of settings, including primary care, specialty outpatient treatment settings, and schools are involved. A few focus on high-risk groups, including those in special education classes, Latinos or Blacks, or those at high-risk for diabetes. Several focus on surgical outcomes in obese adolescents. The results of these studies are expected beginning in 2008 and continuing through 2018. We expect that many more trials will be added to this roster, given the ongoing importance of obesity research.

Future Research

Based on this review, we have several recommendations for priorities for funding additional research in obesity treatment. These recommendations also reflect input from our Technical Expert Panel. The relative importance of funding treatment studies (as compared to prevention studies) is beyond the scope of this report, but bears consideration.

Childhood overweight has been the focus of considerable research in recent years, and certainty in the short-term effectiveness of behavioral intervention programs in school and specialty healthcare treatment settings (and perhaps primary care) is emerging. Replication of behavioral intervention trials (particularly given their heterogeneity of treatment components) is needed to confirm the benefits of these programs, to estimate their likely effects in real-world settings, to determine their feasibility and sustainability, and to report on cost-effectiveness. Understanding important components of behavioral interventions is an ongoing need. To help clarify which components of these programs are most important, researchers should provide consistent and detailed descriptions of treatment components, including information on intensity and duration of treatment components. In addition, trials should report on program adherence, including receipt of treatment, quality of delivery, participant responsiveness, and whether any of these factors varied by subgroups. This would enable reviewers to distinguish small group differences due to difficulty in adhering to the treatment program from ineffectiveness of the program as designed for that subgroup. Consistency in reporting of weight-related outcomes is also crucial for being able to analyze the literature as a body and to allow statistical pooling, as well as potentially exploring the importance of treatment components statistically. Future meta-analyses would be facilitated by all studies consistently reporting at least these weight-related measures: BMI, change in BMI, BMI SDS, and change in BMI SDS. Similarly, all studies and trials of weight management treatments should systematically assess and report on possible harms, on changes in weight-related co-morbidities, on changes in psychosocial and related outcomes, and should monitor and report other unanticipated effects, particularly associated with more invasive treatments. And, once it is established the degree to which multi-factorial treatments can resolve weight-related co-morbidities, it will be critical to establish whether certain intervention components (e.g., increased physical activity, fat-mass reduction, modification of dietary macronutrient or micronutrient intakes) are the key drivers of health benefits.

Longer term followup is needed to confirm maintenance of treatment and other health effects and to assess longer term risks or harms, preferably with outcomes measured at the end of treatment and at fixed follow-up points, such as 1, 2, and 5 years from baseline. As further research elucidates both short- and long-term health benefits, more appropriate clinical treatment planning will be possible, particularly for children and adolescents who are not experiencing immediate weight-related health consequences. There is a particular need for more information on the maintenance of treatment effect in youth taking sibutramine and orlistat for weight loss or undergoing bariatric surgery. Followup data at least one and ideally up to 3 years after pharmaceutical treatment has ended and for at least 2 to 5 years (and ideally through mid-adulthood) after surgery will be very important for determining the impact of these treatments on the ability of adolescents to maintain their weight loss. Given our limited certainty about the quality of the behavioral interventions delivered within current pharmaceutical trials, exploring whether greater treatment effects are possible when pharmacotherapies are combined with proven, effectively delivered behavioral interventions could be important. And, as effective treatment data accrue, it would also be useful to explore whether different subgroups of patients respond better to different types of treatments within a single modality (e.g., different medications or behavioral approaches), different treatment modalities, (behavioral interventions as opposed to pharmacotherapies), or different treatment combinations (e.g., behavioral only vs. behavioral with pharmacotherapy). Similarly, longer term monitoring for harms, treatment failures, or reversals after bariatric surgeries is important to understand their desirability in adolescents who still face growth and maturation issues as well as future reproductive issues. And, as the use of medications to treat obesity increases in adolescents, it will be important to monitor and publish safety information. Large comparative cohort studies could examine real world adverse events and adherence, while case-control studies of obese adolescents taking these medications with age-, weight- and sex-matched controls could help explore rare but serious side-effects. Health care systems with electronic medical records that track BMI, medications, diagnoses, and procedures would be well-placed to conduct such studies.

Ideally, randomized controlled trials comparing bariatric surgeries would provide data to more rigorously evaluate the efficacy of surgical procedures in adolescents. For safety monitoring, and to monitor outcomes in real-world settings, a national prospective registry of bariatric surgery procedures in adolescents with funded data collection and extended followup (outside of clinical care requirements) would be of enormous value. Also, since bariatric surgery is associated with very high costs, linked to both admission and followup by a multidisciplinary team, cost-effectiveness analyses would be very useful.

More studies are needed in understudied populations: in minority children and adolescents for types of treatments; in younger children (5 years and under) for behavioral interventions; and in children who are overweight but not obese, behavioral interventions. Future studies should also evaluate specific approaches that have been advocated by experts for treating excess weight in childhood and adolescence. For example, the Expert Committee 5 has recently advocated a stepped care approach that is pragmatic and evidence-informed, but has never been tested through formal research. Also, we found no controlled trials on more aggressive dietary treatments, such as protein-modified fasts, which may be of use in very obese children for whom more invasive treatments would be considered. It could be beneficial to compare aggressive dietary treatments to both standard weight management approaches such as the stop light diet, and to pharmacological and surgical approaches. Finally, recent data suggest health benefits in adults with physical activity increases (without weight loss); determining whether exercise has a positive effect on health independent of weight loss in children and adolescents could provide an important opportunity for health improvement.

The health effects of childhood obesity (particularly independent of the long-term increased risk of adult obesity and its attendant morbidity) are still not well enough understood. Researchers must ask themselves, “What are the best ways to improve the current and future health of obese, as well as overweight, children and adolescents?” In addition to the research recommendations above, a broader understanding of the prevalence and implications of obesity-related disorders in childhood, and of the natural history of overweight and obesity are needed to answer this question. Documentation of changes in BMI (growth trajectories) and their determinants—-in those who are underweight, normal weight, overweight, and obese, beginning at various time points in childhood and adolescence, and considering males and females and different racial/ethnic subgroups separately—-would be very useful. A better understanding of the natural history of this condition will be important to complement the immediate efforts at prevention and intervention, and will help inform what is considered desirable outcomes from these efforts.

The causes of the dramatic increases in obesity are not well understood, although many potential causes have been hypothesized. Population-based prevention trials targeting factors that have changed in recent decades and that are related to obesity may help determine some causes of the increases in childhood obesity.

Finally, just as the portability of research-tested interventions into the real world must be tested in dissemination trials, it is also important for researchers to make efforts to describe results and implications in real-world terms that can be understand and used by policy makers and the general public. Being clear about how much weight loss a child may be expected to experience, or how much weight gain is prevented, is crucial. It is very useful to lay readers if researchers provide illustrative examples and ranges of outcomes in terms that the public understands, such as pounds (in the United States) or kilograms, since valid research measures, such as BMI and BMI SDS, have little intuitive meaning for most lay people. To the extent possible, it is important for researchers to translate clinical outcomes such as changes in blood pressure and fitness levels into terms that demonstrate whether these changes are likely to have any real impact on a child's health. Ongoing epidemiologic research within children and adolescents who have made favorable weight-related changes to help establish the health impact of various degrees of weight change on short-term and longer term health outcomes will be critical in this regard.

Conclusions

Much headway has been made in the past several years in determining the effectiveness of treatments for obese children and adolescents. Behavioral interventions have been studied in children and adolescents aged 5–18 years, while adjunctive pharmacological treatments or bariatric surgeries have been studied only in highly obese adolescents. Across treatment settings (schools, specialty health care treatment settings, and perhaps primary care) and ages, behavioral interventions have demonstrated beneficial effects on weight compared with no or minimal treatment. Effects are small to moderate after 6 to 12 months of treatment. Some evidence supports more robust effects on weight in specialty treatment settings, with weight changes in some instances similar to those achieved through pharmacological treatments combined with behavioral interventions. Limited evidence supports maintenance of behavioral treatment effects for at least 12 months after treatment ends. Effective behavioral interventions address healthy lifestyle, utilize behavioral management techniques, provide physical activity as part of treatment, and involve parents (particularly in children under aged 12 years). Sibutramine plus a behavioral intervention can lead to moderate weight loss over 12 months of treatment in very obese adolescents, with smaller treatment effects from Orlistat treatment. The evidence base for pharmacological treatments is limited to a one large multicenter study for each type of medication, along with a small number of other trials. No trials provide follow-up after treatment has been discontinued. The research on surgical interventions is limited to fair- or poor-quality case series, which are noncomparative studies, conducted in highly selected morbidly obese adolescents. Few data are available to assess either beneficial or harmful consequences more than 12 months after surgery. Based on incomplete follow up of a limited number of patients, available data suggests that surgical interventions in highly selected morbidly obese adolescents can lead to moderate to substantial weight loss in the short to medium term and to resolution of co-morbidities, such as sleep apnea and asthma. Short-term adverse effects or complications occur in 10 to more than 30 percent and vary with the type of surgery, while longer term risks and maintenance of weight loss is hard to establish with currently available data.

Clarifying the contribution of various treatment approaches in achieving short-term and long-term health benefits (as well as weight loss) is imperative in all ages of children and adolescents and across all levels of overweight and obesity. Given safety concerns and possibly growing use, bariatric surgeries and pharmaceutical approaches require careful monitoring and ongoing research. Since most children and adolescents who are overweight or obese will likely be best-served by behavioral interventions since they appear to have relatively few associated risks, further research in this area is imperative. Thoughtful planning by funding agencies to fund studies that elucidate the role of common behavioral treatment components across a range of overweight subjects and settings would be very beneficial. And, given how difficult it is to lose weight, as evidenced by the generally modest effect sizes for all but the most invasive interventions, efforts to prevent childhood overweight and obesity through obesity prevention strategies and programs offer very important complements to treatment approaches in addressing the current obesity epidemic.

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