Melinda J Ickes1* and Manoj Sharma2 | |
1Assistant Professor, Department of Kinesiology and Health Promotion, University of Kentucky, USA | |
2Professor, Health Promotion & Education & Environmental Health, University of Cincinnati, USA | |
Corresponding Author : | Melinda J Ickes Assistant Professor Department of Kinesiology and Health Promotion University of Kentucky 111 Seaton Building Lexington, KY 40506-0219,USA Tel: (859) 257-1625 E-mail: melinda.ickes@uky.edu |
Received August 08, 2013; Accepted August 23, 2013; Published August 26, 2013 | |
Citation: Ickes MJ, Sharma M (2013) A Systematic Review of Community-Based Childhood Obesity Prevention Programs. J Obes Weight Loss Ther 3:188. doi:10.4172/2165-7904.1000188 | |
Copyright: © 2013 Ickes MJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
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Background: The problem of overweight and obesity has reached epidemic proportions in the United States as well as globally. School-based interventions, after school interventions, home and family based interventions and community-based interventions have been developed to address the problem of childhood overweight and obesity. Understanding the best approach to impact obesity rates is a necessity for health professionals. Therefore, the purpose of this article was to examine the efficacy of community-based interventions targeting childhood obesity and to further develop a set of recommendations for future interventions. Methods: A systematic literature review was conducted independently by two authors in four relevant databases. Inclusion criteria were (1) primary research; (2) overweight or obesity prevention interventions; (3) community-based; (4) studies that used a quantitative design and provided outcome data; and (5) were published through September 2012. Results: A total of 15 interventions met the inclusion criteria, of which six were randomized controlled trials. Eleven interventions were from the United States with one each from Canada, Australia, England and Tonga. Eight interventions utilized a theoretical framework, with Social Cognitive Theory being the most commonly utilized theory. Discussion: Recommendations for future community based interventions include utilization of multiple settings including schools, use of behavioral theory and its explicit operationalization, use of interactive strategies including social support and involvement of parents and family, along with use of environmental change approaches.
Keywords |
Obesity; Overweight; Community; Prevention; Intervention; Program |
A Systematic Review of Community-Based Childhood Obesity Prevention Programs |
In the past 30 years there has been a substantial rise in childhood obesity rates all over the world [1]. In specific terms the worldwide prevalence of overweight and obesity in childhood has increased from 4.2% in 1990 to 6.7% in 2010 and is expected to reach 9.1% in 2020 [2]. In 2010, 43 million children around the world were estimated to be overweight and obese with an additional 92 million at risk of becoming overweight [2]. In the United States, based on the 2009-2010 National Health and Nutrition Examination Survey (NHANES) data, 16.9% (95% CI, 15.4%-18.4%) of children and adolescents between 2 and 19 years were obese [3] These data imply that the problem of overweight and obesity is more severe in the United States. |
Childhood overweight and obesity are associated with several negative consequences. The Bogalusa Heart Study [4] found that childhood obesity is associated with cardiovascular risk factors: of children with a Body Mass Index (BMI) ≥ 95th percentile, 39% had at least two cardiovascular risk factors [5]. Besides impacting cardiovascular risk factors, childhood overweight and obesity also contributes to development of type 2 diabetes, bronchial asthma, sleep apnea, and fatty liver disease [6,7]. Overweight and obesity in childhood is also responsible for several psychological problems such as discrimination, lower self-esteem, depression, body image disturbance, rejection by peers, impaired quality of life, and stigmatization [8-10]. Childhood obesity tends to persist into adulthood. Of children with a BMI ≥ 95th percentile, 65% had an adult BMI ≥ 35 kg/m2, further warranting the need for childhood obesity prevention efforts [2]. |
Childhood overweight and obesity are shaped by many factors [11]. According to the Surgeon General’s Report, for a large majority of people, overweight and obesity result from consuming too many calories and not getting enough physical activity [12]. However, determinants contributing to obesity are often complex and multifaceted. Influencing factors have been summarized into the following six categories [11]. The first set of factors are genetics and biological factors that include genes, gender, parental BMI, height, age, and race. The second set of factors comprise of the influences in the first year of life such as weight at birth, growth in the first year, etc. The third set of influence includes the mother’s behaviors such as breastfeeding, weight gain, and smoking during pregnancy. The fourth set of influences comprise of family food environment and dietary behaviors such as consumption of fat, preferences for certain types of unhealthy foods, consumption of sweetened beverages, large portion sizes, snacking, and family meal times. The fifth set of influence pertains to participation in physical activity along with total amount of screen time (time spent on computers and television). The final set of influence includes environmental factors, such as environments which hinder or encourage being physically active and access to healthy foods. These factors need to be addressed in a comprehensive manner to see an impact on current childhood obesity rates. |
The preventive efforts for combating the problem of overweight and obesity in children have conventionally utilized schools. School-based interventions have a long history, albeit with limited success. Multiple systematic reviews have been published on these interventions, indicating a need for a more comprehensive approach [13,14]. Consequently, in recent years community-based interventions have been introduced. Reviews have been published on after school interventions, prompting a need for further analysis regarding other community-based interventions [15]. Community-based interventions are those which are done in community settings and involve children and/or family members in their activities. There is some evidence that community-based programs are promising [16,17]. However, no systematic analysis assessing the efficacy of such programs has been undertaken. Therefore, the purpose of this article was to examine the efficacy of preventive community-based interventions targeting childhood obesity and develop a set of recommendations for future interventions. |
Methods |
Inclusion/Exclusion criteria |
Inclusion criteria for this review were (1) primary research; (2) overweight or obesity prevention interventions; (3) community-based; (4) studies that used a quantitative design and provided outcome data; and (5) were published through September 2012. Exclusion criteria encompassed (1) interventions that included only process evaluation; (2) obesity treatment interventions; (3) obesity interventions conducted solely in school, healthcare and/or home-based settings (i.e., lacking community component); and (4) studies which were not indexed in the included databases. |
Study abstraction |
An extensive literature search was conducted independently by two researchers to collect studies for inclusion in this review to increase the likelihood that all pertinent articles were retrieved. Searches were performed using the databases Academic Search Premier, CINAHL (Cumulative Index to Nursing & Allied Health), MEDLINE (Medical Literature Analysis and Retrieval System Online), ERIC (Education Resources Information Center). Various combinations of the following keywords were used: [overweight OR obese OR obesity] AND [community] AND [adolescent OR youth OR child] AND [program, prevention, intervention, OR study]. Limits of scholarly journals (peer reviewed) were set. Over 2,800 articles were originally identified using these search criteria. In addition, a thorough assessment of all references cited from the articles identified in the search was conducted to uncover any publications that did not populate during the initial search process. See the PRISMA flow diagram in Figure 1 for a summary of the systematic search results. |
Data extraction |
Data from the studies were extracted independently by two researchers using a standardized form developed by the authors. Any disagreements were examined and the agreed final data recorded. Extracted data included: lead author, publication year, summary of participants, theoretical framework used to guide intervention design and implementation, research design, outcomes, measures used to obtain collected data, description of intervention, intervention frequency and duration, attrition rates, and main findings. |
Results |
Included studies |
Over 2,800 articles were originally identified using the aforementioned search criteria. Of those, 95 full-text articles were assessed for eligibility, resulting in 15 interventions to be included in this review. See flow diagram in Figure 1 for a summary of the systematic search. The included interventions have been summarized in Table 1, giving a description of the target population, measures used, the intervention and design, as well as key findings. The interventions have been arranged alphabetically by first author’s last name. |
Design and sample |
This review was limited to interventions in which a communitybased component was included. Considering the design of the studies reported, 40% (n=6) were randomized controlled trials, in which participants were randomly assigned to the intervention or control group [18-23]. Five (33.3%) of the interventions were quasiexperimental, which did not randomly assign the participants, yet still had a control or comparison group [24-28]. A non-experimental design was also used in four of the interventions (26.7%), in which control and/or comparison groups were not delineated [29-32]. |
Although all of the interventions included a community component to some degree, there was still some variance in setting, with a combination of multiple settings in nine of the interventions. A combination of school-based and community-based was the most frequent setting (n=5) [20,24,27,28,32], with home-based the second most frequent (n=4) [18,19,21,22]. The majority of interventions (n=11, 73.3%) were conducted in the United States [19-21,23,25,27-32] with Canada, Australia, England and Tonga represented internationally. The demographic makeup of participants within the interventions varied greatly. Ten of the interventions included families [18,20-24,28-31], with five focusing only on children [19,25-27,32]. Although these community-based interventions took a population-based approach, there were still those that reported a high number of obese/overweight participants (n=9, 60%), with reported rates as high as 85% [18-20,22,23,25,27-29]. |
The number of participants within each intervention was extremely varied. To differentiate, interventions were categorized from very small to extra large sample sizes. Two of the interventions were very small (under 50 participants), [22,29] one was small (50-100 participants) [30], four were medium (101-400 participants), [18,19,27,30] three were large (401-800 participants), [20,21,32] and five interventions (33.3%) were considered to have a very large sample size (above 800 participants) [23-26,28]. |
Theoretical framework |
Theories and models were widely incorporated into the interventions, with 53.3% (n=8) reporting the use of at least one theoretical framework/model [18-20,23-25,27,29]. Yet, 46.7% of the interventions (n=7) did not mention using a theoretical framework/ model to guide the intervention [21,22,26,28,30-32]. Social Cognitive Theory was the most widely used (n=3) [19,23,27]. Others mentioned included Community Based Participatory Research, Social Ecological Model, and Social Learning Theory. Of the interventions that did use a theory or model, very few explicitly operationalized the constructs of the theory/model (n=3) specific to the intervention [20,25,27]. By explicit operationalization it is meant that the interventions measured the changes in theoretical constructs from before to after the intervention. |
Intervention approach |
Duration of the interventions ranged from eight days (n=1) to five years (n=1) [28]. The duration of 60% of the interventions lasted less than one year; 1½ to 2 months (n=2) [23,30], three to four months (n=3) [27,29,32], 5-6 months (n=2) [18,31], 11 months (n=1) [19]. Five of the interventions ranged from two to five years [20,24-26,28]. Dosage of the intervention also varied, with weekly to monthly sessions. |
A variety of strategies were used within the design and implementation of each of the interventions. All of the interventions promoted general education and awareness to some degree. To evoke behavior change, skill building (n=6) [18-20,27,29,30], goal setting (n=5) [18,19,22,23,30], and engaging participants in physical activity (n=5) [19,22,25,29,32] were the most widely used strategies. Two of the interventions mentioned building capacity as an initial planning phase of the intervention [24,30]. Other activities incorporated included use of gardening, community field trips, family fun days, and worksite health screenings. Over ninety percent of the interventions (n=14) reported some degree of parental involvement [18-31]. In addition, environmental changes, including alternate food options at schools, restaurants, and worksites, were incorporated into 46.7% of the interventions (n=7) [18,24-26,28,30,31]. The interventions were implemented by school personnel (n=4), [20,23,24,29] trained staff (n=2) [27,31] community workers and mentors (n=2) [19,31], counselors (n=1) [18], and parents (n=1). Three of the interventions mentioned implementation varied dependent on intervention phase [25,26,28]. Seven of the interventions mentioned the use of incentives throughout recruitment, implementation and/or follow-up phases [18,21-23,25,27,32]. |
Intervention outcomes and measures |
All of the interventions provided outcome data, although the primary outcome varied. BMI was the primary outcome for 60% (n=9) of the interventions [19,20,23-26,28,29,31], while nutrition and/or physical activity behaviors were the primary outcomes for six of the interventions [18,21,22,29,30,32]. Other measures included attitudes (i.e., preferences) toward nutrition choices, general knowledge, theoretical constructs (i.e., readiness, self-efficacy, etc.), and other biometric measures (i.e., blood pressure). |
It is important to recognize that 80% (n=12) of the interventions reported positive changes throughout the intervention when comparing the identified primary outcome [18-27,29,32]. Of those measuring BMI as a primary outcome, 88.9% (n=8), indicated an improvement [18-20,23-26,29]. Four of the interventions reported improved nutrition and/or physical activity behaviors or attitudes [21,22,27,32]. Details on intervention outcomes are summarized in Table 1. Out of the 15 interventions, seven conducted follow-up measures beyond postintervention. Two were within 3-4 months [22,23] and five were within 1-3 years post-intervention [19,20,24,26,31] (Table 2). |
Discussion |
Childhood obesity is of concern because of the negative impact on the child’s physical, psychological, behavioral, and social health. With the large number of children and adolescents affected by overweight and obesity, prevention of childhood obesity has become a national public health priority [33]. The purpose of this review was to examine the efficacy of preventive community-based interventions targeting childhood obesity and develop a set of recommendations for future interventions. Based on a review of the resulting 15 interventions, it is evident community-based interventions are important settings to target, and may have sustainable impact across all populations. |
Community-based interventions seem to approach obesity prevention from an ecological perspective, considering the individual, the home, school, neighborhood, as well as surrounding environmental influences and policies [34]. Differences in culture and values within a community are able to be considered and integrated into intervention design [20]. Even though all interventions included a community component, majority were implemented in multiple settings. A third of the interventions included a school component. This makes sense considering the capability of reaching both parents and children, and the potential for a supportive environment to evoke behavior change. When including a school-based component, it may be easier to incorporate an experimental design. While 40% of the interventions reported such a design, the reality is it may be more difficult to include randomization when targeting an entire community. Community-based interventions tend to be larger in size, with most of the interventions targeting over 400 participants. It is recommended that future research determine best practices for research design and implementation for such large-scale studies. |
All of the included interventions focused on primary obesity prevention. Primary prevention strives to prevent obesity from occurring, thereby reducing both the incidence and prevalence, and associated healthcare costs [34]. However, considering at least 60% of the intervention populations included high rates of obesity, this may not be the most appropriate approach, particularly in high-risk populations. It is important for future research to consider tertiary (i.e., treatment) versus prevention approaches, and/or a combination of the two, depending on targeted community. |
Theory-based health behavior change programs are thought to be more effective compared to those that do not use theory [34]. Of the included interventions, slightly over half incorporated the use of behavioral theory, with Social Cognitive Theory used most frequently. Social Cognitive Theory tends to be widely used in obesity prevention interventions [14]. Understanding the influence of the individual, environment and behavior on related choices is important to promote lifestyle changes. Regardless of the theory used, theorybased interventions aid in the development of measurable program outcomes, help in the initial design of the interventions, provide a framework for effective programming strategies, and increase the likelihood of successful replication [34]. Of the interventions that did use theory, very few explicitly operationalized the constructs of the theory and measured changes in the related constructs from pre- to post-intervention. This is important as it provides an understanding of which components are working, which are not, and also helps improve the theoretical application. Thus, when designing future interventions, theory should be used as a framework, but associated constructs must also be adequately measured with validated instruments [14]. |
A variety of strategies were used within the design and implementation of each of the interventions. All of the interventions included a focus on increased knowledge and awareness, particularly related to nutrition and physical activity behaviors. Although a change in knowledge is integral to the foundation of many interventions, it does not necessarily evoke behavior change [30]. Focus should be on implementing health education that provides individuals with the knowledge, attitudes, skills, and experiences needed for healthy living. Individuals must learn to build relevant skills to successfully make behavior changes that will foster maintaining health behavior change. Recommended strategies include the use of developmentally appropriate materials, incorporating strategies that are interactive, engage all participants, and are relevant to the individual’s daily life and experiences [35]. It is also recommended programs focus on participation in positive behaviors rather than limiting negative behaviors, which may increase participant buy-in and long-term success. Only one third of the interventions incorporated physical activity into the intervention. Providing the opportunity for physical activity may help to build self-efficacy for future participation. |
To maximize potential for behavior change, appropriate strategy selection is essential. Intervention strategies which evoked the most promise in this review were comprehensive in nature. They implemented multiple components, included hands-on activities, skillbuilding and knowledge activities, and incorporated environmental changes along with a social support component. School personnel were used to facilitate and/or disseminate close to 30% of the interventions. Typically, school personnel already have high levels of rapport with parents and children [20]. This is an important point considering efforts to promote sustainability of such intervention approaches. Regardless who is in charge of program facilitation it becomes critical to include training opportunities before, during and after the intervention. |
Parents were involved in over 90% of the interventions. Family plays a critical factor in the majority of nutrition and physical activity behaviors of children. The family can shape students’ behaviors in a variety of ways, including availability and access, expression of attitudes related to obesity-related behaviors, and being recognized as role models for healthy behaviors. Interventions should encourage communication among parents and motivate families to promote long-term adoption of healthy behaviors [35]. Further research should explore how adoption of healthy behaviors leading to parental behavior change can be leveraged to result in child behavior change [21]. |
Beyond an individual level approach, almost half of the interventions incorporated environmental changes. Such changes included menu labeling at community restaurants, school nutrition policies, worksite initiatives, and improving policies promoting breastfeeding. “The complex nature of the etiology of obesity demands far-reaching interventions that penetrate every aspect of a child’s world.” [25]. Environmental and policy influences may potentially be the most powerful, but currently least well understood, strategies for addressing child obesity [33]. Recommendations continue to incorporate strategies which affect environmental change, including providing access to healthy foods and opportunities for physical activity, along with promoting a culture which encourages healthy behaviors throughout the community [35]. Although more interventions are including environmental changes, there is still a need to fully understand feasible and effective strategies, particularly when dealing with larger communities. |
The potential impact of community-based obesity prevention interventions is reinforced by the reported success of these included interventions. With the varying research design, duration, and primary outcome measures, only limited comparisons can be made across studies; however, it is important to recognize that 80% of the interventions reported a positive impact on the primary outcome. Typically, those interventions lasting six months or less reported improvements in attitudes, knowledge, and behaviors related to nutrition and physical activity [18,22,27,30-32]. For example, Hawley and colleagues did not report changes in behavior, but did report improved readiness to change [30]. |
There were eight interventions reporting a significant decrease in BMI, which is promising considering the correlation between a decreased BMI and risk for morbidity and mortality [33]. The majority of interventions reporting improvements in BMI and/or overweight and obesity prevalence were longer in duration, 11 months to 4 years. However, there were two interventions with duration of 6-10 weeks which also reported decreased BMI. Weber et al. [23] did report significant decrease in BMI at six weeks post-intervention; however, this was not maintained at the four month follow-up. Echevarria and Pacqulao [29] also reported decreased BMI at 10-weeks postintervention. Results may have been impacted due to the thorough planning process of the researchers, highlighted by the inclusion of a needs assessment among the targeted population. This may well have contributed to the motivation and readiness to change among intervention participants. Very few of the interventions conducted a long-term follow-up measure. Sustainability of behavior change and BMI surveillance needs to be considered. For example, according to Black et al., it was not until delayed follow-up that the intervention effects on BMI and body composition were observed [19]. Therefore, recommendations on duration of intervention need to be further explored. |
More intensive and environmental interventions may be required to maintain dietary and PA changes. A change in BMI follows significant behavior changes, including maintenance of dietary and physical activity changes. Therefore, more intensive interventions may be required to sustain such behavior changes, and ultimately lead to significant improvements in BMI. There is a need to continue community support once the intervention is complete. The longer the intervention, the more likely attrition rates tend to increase. Included interventions reported 4-56% attrition. Future research needs to consider the impact of intrinsic and extrinsic motivation within community-based interventions in hopes to decrease attrition throughout the intervention. Karanja et al. mentioned the impact strong community collaboration in the development phase can have on decreased attrition rates [31]. |
With the continued promise of community-based interventions, there needs to be an effort to use existing evidence-based guidelines as the foundation for developing, implementing and evaluating such obesity prevention interventions. Most communities might not able to implement all recommendations at once, but it is possible to build in selected strategies, and consider a long-term plan. Table 3 summarizes key recommendations for future community-based interventions in the area of childhood obesity. |
Limitations |
It is important to note the limitations of this review. This is a qualitative review and not a quantitative meta analysis. The purpose of the review was to summarize community-based interventions designed to prevent childhood obesity. Further, the interventions included were limited to those in the English language, published through September 2012. This precluded interventions not published in the English language, those not including a community-based component, those not reporting outcome results, and those studies published after September 2012. |
It is also necessary to mention publication bias as a limitation to any systematic review, due to the major threat to validity. Only a small number of intervention studies reach publication in an indexed journal and are in turn easily found through systematic database searches. Typically, statistically significant, positive results indicating optimal outcomes are more likely to be published, particularly in high impact journals. Similarly, studies with more robust design and large sample sizes tend to be published more frequently. This systematic review included all studies that were indexed in the relevant databases, however, it is understood that other non-peer reviewed studies may be available. The systematic nature of this review and explicit search criteria provide rationale for inclusion/exclusion of all studies. As this is a narrative review, comparisons can be made between intervention strategies, target population, and reported outcomes. However, future meta-analysis should aim to include grey literature along with the peerreviewed studies since statistical comparisons can then be made. |
Conclusion |
With 43 million children around the world considered overweight or obese and an additional 92 million at risk of becoming overweight [2] targeting childhood obesity worldwide has become a national priority. Community-based interventions are important in combating childhood obesity, since it will take the combined efforts and collective strength of schools, families, and communities to reverse obesity trends. The potential impact was evident considering of these 15 interventions, over 80% achieved success. The use of multi-component interventions that address multiple influences on health behavior such as family and community norms, enhanced knowledge, skill-building, accessibility of healthful food options and opportunities for physical activity, is crucial for effective approaches. Continuing to implement evidence-based obesity prevention interventions will hopefully lead toward a decline in these staggering obesity rates. |
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Table 1 | Table 2 | Table 3 |
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Figure 1 |
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