Childhood obesity is a serious public health concern worldwide [1
]. In Canada, the prevalence of overweight and obesity in children has increased over recent decades. In 2004, it was estimated that over 25% of Canadians aged 2 to 17 years were overweight or obese, which is a significant increase from 15% recorded in this age group in 1979 [4
]. Given this trend towards weight gain in children [5
], and the mounting evidence that overweight and obesity may track through to adulthood [6
], it is clear that childhood obesity is a public health crisis that must be addressed.
Further to the growing body of literature showing increases in obesity prevalence, there are also compelling data demonstrating a positive relationship between obesity and risk for future chronic disease. Specifically, an elevated body mass index (BMI) in children greatly increases the likelihood of developing type 2 diabetes, hypertension, hyperlipidemia, nonalcoholic fatty liver disease, orthopedic complications and sleep apnea [11
]. Furthermore, an elevated BMI is associated with the metabolic syndrome, which includes a constellation of cardiometabolic risk factors such as central adiposity, dyslipidemia, dysglycemia and elevated blood pressure [11
It is estimated that as many as 30% of obese adolescents have the metabolic syndrome [13
]; a concerning observation as these children have an increased risk of developing diabetes mellitus and cardiovascular disease in adulthood [14
]. In addition to developing serious medical co-morbidities, overweight and obese children are also at a higher risk of experiencing psychological problems including mood and anxiety disorders [19
]. Furthermore, overweight children may suffer from early discrimination [21
] and an overall poorer quality of life [23
]. The current burden of childhood obesity on both medical and psychological well-being makes it important to develop effective interventions in this population.
Currently, options for long-term management of obesity include programs targeting behavior surrounding diet and exercise, pharmacological agents, and bariatric surgical approaches. In the pediatric population, lifestyle modification interventions should be the first line of treatment when dealing with this problem, given the invasiveness of other approaches [24
]. Such interventions must specifically focus on teaching the family effective strategies to improve their dietary intake, to increase their levels of physical activity, and to decrease their sedentary behavior.
Lifestyle and behavior modification approaches have been found to be efficacious to treat childhood obesity, at least in the short-term [25
]. Results from a recent meta-analysis suggest that, in randomized control trials, interventions in the pediatric population have resulted in an 8.2% to 8.9% decrease in weight compared to controls who have observed an increase in weight of 2.1% to 2.7% [25
]. Therefore, lifestyle behavioral interventions compared to standard care can produce clinically significant reductions in weight for children and adolescents [28
]; however, these programs have yet to be evaluated in Canada once implemented in a clinical setting.
The objective of this study was to evaluate the Centre for Healthy Weights—Shapedown BC (CHW-SB) familial intervention program targeted at overweight and obese children by assessing the change in weight trajectories from program intake date to program completion date. We hypothesized that the CHW-SB program would decrease the slope of the weight gain trajectory in children over the course of the 10-week program. Our secondary outcomes included changes in clinical, biochemical and psychological parameters, as well as changes in physical activity levels in program participants.
The CHW-SB family-centered lifestyle intervention is the first naturalistic obesity treatment program cohort to be evaluated in Canada. During the program, participants’ weight gain slowed significantly compared to weight gain observed while waiting for the program to begin. This resulted in a dramatic reduction in the slope of the weight change trajectory from Phase 1 (before program: intake to baseline) to Phase 2 (during program: baseline to evaluation). Furthermore, longitudinal mixed effects regression analysis revealed that more days spent in the program resulted in a greater reduction in weight trajectory. In addition to these encouraging changes, when BMI was standardized for the child’s age and sex by conversion to a z
-score, we observed that BMI z-
score was also significantly reduced in participants during the 10-week program. These findings are of utmost clinical significance given recent data demonstrating that impaired glucose tolerance can be reversed if BMI is stabilized and that the probability of impaired glucose tolerance progressing to type 2 diabetes increases if BMI continues to rise [48
At least 17 other pediatric obesity intervention programs similar to the CHW-SB program exist in Canada; however, to our knowledge, formal evaluation of these programs has not yet been reported [49
]. In the United States, Dreimane et al.
also evaluated a family-centered, weight management program for overweight children [50
]. Like the CHW-SB program, this program (Kids N Fitness) was an outpatient hospital-based program for children and their families that utilized exercise and nutrition education and behaviour modification and also included participants developing exercise and nutrition goals during the program. Consistent with our results, children who participated in Kids N Fitness had lower weight velocity and had reduced BMI z
-scores during the 12-week program compared to before the program started. Furthermore, this study also noted improvements in emotional well-being as measured by a Child Health Questionnaire. Savoye and colleagues [51
] also implemented a weight management family-based program called Bright Bodies
for overweight children and found that after 12 months, participants gained significantly less weight during the program than controls. Like CHW-SB, this program also utilized a behaviour modification component, exercise component, and a nutrition education component focusing on a non-diet approach. In addition, the program evaluated by Savoye et al.
] found that after one year, BMI and body fat were reduced compared to control subjects. These results are also consistent with another urban weight management program evaluation conducted by Evans and colleagues where after six months, BMI z
-score was found to decrease by 1.2% [52
]. In a longer evaluation time-frame, Vignolo et al.
] found that five years after a multi-disciplinary, hospital-based outpatient weight management program similar to the CHW-SB program, children who participated had significant reductions in mean BMI standardized for age and sex (baseline: 4.23 ± 0.71 versus
5-year follow-up: 2.74 ± 0.85). It will be important to continue to evaluate CHW-SB
program to assess whether the positive results reported herein can be sustained over the long-term.
Along with improvements in weight and z
BMI seen in CHW-SB participants came improvements in some of the metabolic syndrome components. Waist circumference decreased considerably over the relatively short evaluation time period of 10 weeks. This reduction is clinically relevant, since it has previously been shown that abdominal adiposity is a serious risk factor for cardiovascular disease [54
]. Furthermore, we observed a decrease in fasting insulin and a trend for a decrease in HOMA-IR. Given that previous studies [55
] have demonstrated that obesity, and glucose intolerance in childhood have been strongly associated with increased rates of premature death, interventions that improve these parameters are of utmost importance in this population that is still growing and developing.
The CHW-SB program also resulted in dramatic increases in physical activity. MET*minutes of exercise and moderate physical activity both increased by almost 50% and minutes of physical inactivity decreased by 38% over the 10-week program. In Virginia, TEENS was developed as a weight management program for adolescents with BMI ≥ 95th
]. Like CHW-SB, TEENS is run as an outpatient program out of a children’s hospital and includes components of medical assessment, nutrition and behavioural modification. In addition, TEENS also involves a rigorous exercise program. In an evaluation of TEENS conducted by Evans et al.
, it was found that in addition to a decrease in BMI z
-score, there was a significant improvement in cardiorespiratory fitness; however, unlike CHW-SB
, this program found a non-significant (p
= 0.08) improvement in hours of moderate physical activity per week [52
In addition to the significant improvement in adiposity, metabolic, and physical activity profiles observed in participants, the CHW-SB program also resulted in both clinically significant reductions in self- reported anxiety and increases in self-concept (self-esteem) as measured on the Beck Youth Inventories Second Edition. Our results are consistent with both the results of the Kids N Fitness where, after 12 weeks, participants’ emotional well-being and behaviour improved [50
] and with a 5-year evaluation of Mi Piace Piacermi
, where participants’ emotional and social behaviours improved [53
]. As well, similar results were observed in the previous evaluation of the Shapedown
program where after 15 months, a large improvement in self-esteem was observed both in a general population of overweight children and in a sub-population of obese children with type 2 diabetes [29
]. These findings are especially important given the vast literature describing that obese children have a greater incidence of internalizing and externalizing problems, lower social competence and reduced self-esteem [57
While other North-American weight management programs for overweight children have been successful in the past, the multi-disciplinary, family-centered approach, coupled with group therapy and a comprehensive medical evaluation, makes the CHW-SB program unique [49
]. In conjunction with the diverse nature of the program, our program evaluation also included adiposity, biochemical, psychological and physical activity measures, which allowed us to assess multiple aspects of this weight management intervention. Because obese youth have been previously found to have co-morbid psychological and medical complications, it is vital that both our program and evaluation methodology include a comprehensive, multidisciplinary approach. Moreover, by taking advantage of the time that children waited for program commencement (Phase 1) to obtain a natural control for weight changes observed during the program (Phase 2) allowed us to assess the effect of CHW-SB program on the weight trajectory, which was important for accurate analysis of the program’s impact over the short-term.
5. Strengths and Limitations
The results of this study must be interpreted within its limitations. The main limitation of this study was that we did not have a standard control group. Nonetheless, we were able to utilize the waiting period before the program began to use each child’s data from baseline to intake as their own “control” for their changes during the program. Having a naturalistic comparison for weight changes that is appropriately matched for age and sex is a strength of this study. The lack of full follow-up is also a limitation in interpreting the effectiveness of this program, as drop-out may be associated with lack of success in meeting program goals. The longitudinal analysis ameliorates this issue but does not avoid it completely. The analyses of changes between visit 1 and visit 10 may reflect bias in the optimistic direction. Additionally, the PAQ only examined participants who attended >7 sessions; thus improvements in physical activity observed in our evaluation may be linked to attendance.
Unfortunately, we were not able to assess whether the CHW-SB program decreased the prevalence of dyslipidemia and hypertension since these parameters were not measured at evaluation. It will be important that future program evaluation include analysis of these parameters to properly assess the programs influence on the metabolic syndrome. Furthermore, our evaluation did not include an assessment of nutrition or an objective assessment of physical activity. Both are important to include in subsequent evaluations to help us understand which behaviours are modified as a result of intervention.
While we had positive results, they were of modest magnitude, and our evaluation did not include long-term follow-up. Our evaluation was limited because government funding for the CHW-SB program did not include the cost of program evaluation. Future program support should include means for long-term systematic evaluation to assess program effectiveness and ensure that tax-payer dollars are being spent appropriately. Finally, our participation rate of 71% is a strength as it is an improvement on participation rates of 63% reported in a weight intervention program of similar duration in children [50