Challenging Dogma - Spring 2008

...Using social sciences to improve the practice of public health

Sunday, April 20, 2008

Childhood Obesity: Characterizing the Failure and Potential Successes of Public Health Interventions on a Growing Epidemic—Lori L. Harrington, MD

Public health interventions over the years have been successful in improving the health and lives of children. However, there remains a growing and pervasive public health crisis amongst our children— obesity. Despite public health campaigns to intervene, childhood obesity continues to be an epidemic problem in the United States. According to two National Health and Nutrition Examination Surveys (NHANES), from the 1976-1980 survey and the 2003-2004 survey, the prevalence of overweight children and teenagers has increased substantially (1). For children aged 2–5 years, the prevalence of overweight increased from 5.0% to 13.9%; for those aged 6–11 years, prevalence increased from 6.5% to 18.8%; and for those aged 12–19 years, prevalence increased from 5.0% to 17.4%. This represents a 2-3 fold increase in the rates of obesity over a period of twenty-five years (2). This growing problem has grave health implication during childhood and as these children grow into adults. Obesity in childhood leads to hypertension, high cholesterol, increased rates of diabetes and cardiovascular disease, sleep apnea, asthma, exercise intolerance, osteoarthritis, as well as psychosocial consequences of obesity (2). Current public health strategies addressing this epidemic of childhood obesity narrowly focus on individual behaviors and these health risks of obesity, and are largely unsuccessful. Instead, a broader, more comprehensive approach, including other social and behavioral strategies to influence social norms, may be more successful.

A Current Public Health Strategy and the Health Belief Model
Public health prevention strategies to target childhood obesity narrowly rely on individual behavior, focusing on health risk and medical complications of obesity as an unsuccessful strategy of change. As a prime example, the highest federal authority of health in the United States, the US Department of Health and Human Services (HHS) and the Surgeon General have released a “Call To Action To Prevent and Decrease Overweight and Obesity,” with a focus on children and adolescents (3). The focus of this message is on the medical and health consequences of childhood obesity and addresses children and parents about the behavioral changes that should be made in order to avoid these consequences.

This strategy is clearly based on the Health Belief Model of change in behavior. It depends on the individual, the child or parent, to weigh their perceived susceptibility of developing the consequences of obesity and the benefits of avoiding those consequences, against their behavior including food and activity choices. This campaign then requires this individual to make a rational choice to decide to change their behavior and assumes change will come with the intention to do so, which is not accurate assumption. However, this campaign does not address any social or behavioral factors--economic, psychological, ethnic factors-- that may influence the decision to change or limit the ability of making that intention into an actual change. These limitations are barriers that the Health Belief Model falls short of addressing and are the likely reasons campaigns such as this one fail.

Social and Behavioral Factors
A more successful strategy for change in childhood obesity must identify behavioral, social, cultural and environmental factors that influence the increasing epidemic of childhood obesity. These strategies focus on a population-based approach to the problem, which may be more useful on this society-wide problem (4) (8) than an individual based approach. Anthropological changes such as activity level, technology, the built environment, family structure, and family activity; geographic changes in society; as well as sociologic factors including socioeconomic status, racial and ethnic influences are key factors in the development of the obesity epidemic and so must be considered in its prevention and resolution.

The progression of childhood obesity parallels the changing social norms of activity and diet change over the last few decades. Technological advances have come with the detriment of those changes including the immense decrease in activity level of children. Childhood entertainment, which used to be outdoor play and physical activity, has been replaced by the sedentary play of 300 cable channels, a myriad of video games, and the virtual world of relationships afforded by the Internet. None of these activities promotes physical fitness. An estimated 61.5% of children aged 9 to 13 do not participate in any organized physical activity during their non-school hours and 22.6% do not engage in any free-time physical activity (11). School support of physical activity has also declined, as school boards remove physical education from the curriculum and after-school sports programs require fees to participate, putting these activities out of the reach of some students. Only a small minority of children has daily physical education class time, and in those who do, active class time is far below 50% (10), even though this study by Datar et al. showed physical education classes were an effective intervention, especially for obese or at-risk girls. Changes in our built environment have also decreased children’s activity level (15). Most travel and transportation is by car; walking is no longer the mainstay of travel. As crime increases in neighborhoods, and as parents are out of the home more frequently for work, children spend more time indoors to avoid unsafe or unsupervised situations and less time in outdoor physical activity.

Along with decreased activity, changes in the diets of children and their families have worsened the obesity problem. In general, children’s diets have been influenced, to their detriment, by their parents’ diets, by unhealthy cultural norms, and by corporate America. Childhood obesity is a part of a greater problem of obesity in the general population, allowing children to recognize their adult role models’ weight as an acceptable social norm, a norm they are easily able to mirror. Children of obese mothers had double the odds of being obese compared with children of normal-weight mothers (5). A family based intervention strategy reported by Rodearmal et al (7) in which a family, with at least one obese child, decreased calorie intake and increased physical activity showed significant decrease in body mass index (BMI) of the target child. This finding suggests that a family strategy to incorporate both children and adults could be useful in obesity prevention.

Race, ethnicity, and socioeconomic factors are societal factors that must be considered in approaching the prevention of childhood obesity. In the United States, prevalence of obesity rose more than twice as fast among minority groups compared with white groups (2). A study by Kimbro et al (5) of overweight toddlers showed that Hispanic children were twice as likely as black or white children to be overweight or obese. Haas et al (6) identified black and Latino children as twice as likely of being overweight compared with white children, and Latino adolescents as more likely than whites. Kimbro’s study (5) identified factors such as culturally determined food intake patterns, less avoidance of fat containing foods, and greater consumption of whole milk compared to whites as factors contributing to the racial disparity in childhood obesity. An additional racial disparity was also identified by Kimbro: black and Hispanic mothers frequently do not identify their overweight children as overweight. Hispanic mothers, especially those who are less acculturated, are more likely than women in other groups to hold the common cultural belief that chubbier children are healthier. These disparities decreased only slightly when controlling for other child and maternal factors, suggesting that underlying cultural factors influence childhood obesity. Other social factors identified by Hass et al (6) include children from families in which parents had lower educational levels, lower income, and lack of health insurance as having a greater risk of being obese. The results from these studies suggest the need for tailored interventions to include social and cultural differences when approaching obesity.

Community and Industry Factors
Identification and incorporation of stakeholders from corporation and industry, down to the family and community level is essential in changing social norms to focus on eradication of childhood obesity. A broad societal strategy, rather than focusing on the traditional individual responsibility, (13) and a population based action plan is necessary. This action plan must focus on both public and private sectors in our communities.

Focusing on family, school, and community level interventions transitions the focus from individual level factors to group level factors. The model of social expectations theory in which social norms, values, and social roles affects people’s behavior supports this population focused approach. By slowly transitioning social expectations to no longer encourage or accept obesity, just as was successful in smoking in public places, public health may be able to change social norms. An approach focusing on families (7), community, and schools may be a first step. Interventions could include designing communities to encourage physical activity, increasing community access to nutritional food sources, and decreasing the ease of availability to fast food (8). School interventions that have been successful include implementation of physical education classes (10) and implementation of coordinated healthier eating programs (9).

A large component of community intervention must also include a focus on private industry and their part in the growing obesity epidemic. The food industry has been very effective through marketing and advertising in reaching extensive segments of the population and making their products household names. Household income spent on away-from-home foods rose from 25% of total food spending in 1970 to nearly one-half in 1999 (11). Using the same theories of branding in social marketing and making promises in advertising theory, industry can be instrumental in constructively addressing childhood obesity prevention by developing and promoting healthful products, consistent healthy messages, and creating a healthy eating environment. Public health practitioners should implement marketing research used by industry in order to understand peoples’ preferences, attitudes, intentions, and behaviors, which may be helpful in devising strategies for long-term behavioral changes (12). In addition to using industry strategies to make public health change, the food industry needs to make changes of their own.

Today’s food marketers spend an estimated $10 billion annually to reach children through measured media—television, radio, print, and Internet—with additional expenditures for promotions, video games, and text messaging (14). Children and youth aged 11 to 18 years visit fast food outlets an average of twice a week, and those who ate fast food consumed more total calories and fat, sweetened beverages, and fewer fruits and vegetables, and less milk than those who did not consume fast food. Fast food consumption is associated with a diet high in calories and low in nutrients and served in large portion sizes (11). The Institute of Medicine (IOM) (11) has made suggestions to the food industry including: expanding healthier meal options, decreasing serving sizes, and providing the nutritional information of their products at the point of purchase. The IOM has also called on companies to change their practices on targeting children and has asked Congress to enact legislation to this end (14). McDonald’s, the largest food service company in the world, has actually begun instituting some of these recommended changes including removing the “Supersize” option, adding more nutritional options to their menu, promoting these options in the media, and making available nutritional information on their product packaging. However, they continue to undermine these options and promote unhealthy eating by pricing differences and continuing directed advertising to children (14). The food industry has an incredible amount of popularity and therefore power and should consider using their name to help in addressing the problem of childhood obesity.

The current public health approach to childhood obesity erroneously focuses on the individual and their behavioral choices to combat obesity. These strategies have not been successful in preventing or reducing childhood obesity. Instead, a new public health approach must be directed toward the many other social and behavioral factors that influence the development of obesity in the approach toward reducing obesity including racial and ethnic disparities, insurance status, and socioeconomic status. In addition to focusing on these identified social disparities in a new action plan to combat obesity, public health should use the food industry as an ally to combat obesity and consider taking advantage of their successful marketing strategies in the action plan approach.

1. Centers for Disease Control.
2. Ebbeling CB, et al. Childhood obesity: public-health crisis, common sense cure. Lancet. 2002, 360: 473-82.
3. United States Department of health and Human Services. The Surgeon General's Call To Action To Prevent and Decrease Overweight and Obesity. January 2007.
4. American Academy of Pediatrics Policy Statement. Prevention of Pediatric Overweight and Obesity. Pediatrics. 2003, 112 (2): 424-430.
5. Kimbro RT, et al. Racial and Ethnic Differentials in Overweight and Obesity Among 3-year Old Children. American Journal of Public Health. 2007, 97: 298-305.
6. Haas JS, et al. The Association of Race, Socioeconomic Status, and Health Insurance Status With the Prevalence of Overweight Among Children and Adolescents. American Journal of Public Health. 2203; 93: 2105-2110.
7. Rodearmel SJ, et al. Small Changes in Dietary Sugar and Physical Activity as an Approach to Preventing Weight Gain: The America on the Move Family Study. Pediatrics. 2007; 120:869-879.
8. Koplan JP, et al. Preventing Childhood Obesity: Health in the Balance. Institute of Medicine of the National Academies. Washington DC. National Academies Press. 2005.
9. Veugelers PJ, et al. Effectiveness of School Programs in Preventing Childhood Obesity: a Multilevel Comparison. American Journal of Public Health. 2005;95:432-435.
10. Datar A, and Sturm R. Physical Education in Elementary School and BMI: Evidence from the Early Childhood Longitudinal Study. American Journal of Public Health. 2004; 94:1501-1506.
11. Institute of Medicine of the National Academies. Industry Can Play a Role in Preventing Childhood Obesity. Fact Sheet. September 2004.
12. Institute of Medicine Regional Symposium. Progress in preventing Childhood Obesity: Focus on Industry. Beckman Center of the National Academies. December 1, 2005.
13. Burros, M. New Approach to Childhood Obesity Urged. NY Times. Oct 1, 2004.
14. Lewin A, et al. Food Industry Promises to Address Childhood Obesity: Preliminary Evaluation. Journal of Public Health Policy. 2006; 27: 327-348.
15. ICF International. Childhood Obesity Prevention. August 2007.


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