Research plays a critical role in helping us understand and address our most serious health issues. Childhood and adolescent obesity has become a paramount health crisis in the past decade, and evidence from the field makes clear the factors fueling this country's epidemic rates. New data indicate that unhealthy nutrition practices are typically the norm in our schools, especially in the secondary grades [1]. Students of all ages have too few opportunities for physical activity in school [2], and their activity levels only decrease as they get older [3]. Because of research, we can definitively link higher body mass index levels with consumption of sugary beverages [4], [5], more costly produce [6], and excessive screen time [7], [8].
Along with deleterious environmental changes, these factors have pushed childhood and adolescent obesity rates sharply higher since 1970. Nearly one-third of U.S. youths now are overweight or obese, and among those ages 12 to 19, obesity rates have more than tripled [9]. Statistics help us comprehend the scope of the problem, whereas the stories behind the numbers remind us of the devastating impact obesity has on so many individuals.
Today, many parents think obesity is a greater danger to their child's health than drug abuse, smoking, and unsafe sexual behavior [10]. Their concerns are well justified. Obese adolescents are increasingly being diagnosed with conditions once considered adult illnesses, such as type 2 diabetes and hypertension [11]. They have a higher lifetime risk for a host of serious health problems, such as heart disease, stroke, diabetes, asthma, and some forms of cancer [11]. The stigma of obesity carries psychological and social consequences as well, including an increased risk of depression, as obese adolescents are rejected more frequently by their peers, teased and ostracized because of their weight [12]. The evidence offers a discouraging prediction: the chance of an obese teen becoming an obese adult is as high as 80% [13].
Direct medical expenses attributed to childhood obesity are estimated at $14 billion annually [14]. When we expand this estimate to include direct medical expenses for obese adults and the value of wages lost by people who are unable to work because of a weight-related medical problem, the figure jumps to a staggering $117 billion [15]. These costs already are taking a toll on our healthcare system and economy—even before our most obese generation of children reaches adulthood.
Other consequences of obesity are more difficult to measure. For example, how do you calculate the cost of falling behind in class? Obese adolescents are more likely to miss school than their normal-weight peers [16], which makes it harder for them to keep up academically. This not only affects their college and then career prospects, it has the potential to hurt our competitiveness as a nation.
Indeed, the best available research tells us that the obesity epidemic, if it is not abated, threatens our workforce, healthcare system, and economy for decades to come. So how do we begin to address this crisis?
The Robert Wood Johnson Foundation has committed $500 million to remove the barriers that keep children from eating a healthy diet and engaging in regular physical activity. We believe that reversing the epidemic requires concerted efforts by policy makers, public health officials, school and community leaders, the food and beverage industry, families, and other important stakeholders. Individual efforts, ideally done in collaboration, can change policies and environments to improve access to nutritious foods and safe places to play for young people everywhere.
The Robert Wood Johnson Foundation is investing in three interlocking strategies of evidence, action, and advocacy. The articles presented in this supplement come from grantees funded through two of our national programs, Healthy Eating Research and Active Living Research, which investigate policy and environmental approaches to preventing childhood obesity. Building a solid evidence base will help us learn how we can best change the policies and environmental factors that have contributed to the problem. What we learn from our research must be quickly translated to inform advocates and drive action. At the same time, we work with advocates to identify what new research questions need to be asked and answered. In this way, each prong of our strategy informs and reinforces the others.
Based on our research to date, the Foundation is pursuing changes that will provide healthier foods to students at school; improve all Americans' access to affordable nutritious foods; increase the frequency, intensity, and duration of physical activity in schools; improve access to safe places where children can play; and limit sedentary screen time. We are particularly focused on the youths who are at greatest risk for obesity: African American, Latino, American Indian and Alaska Native, Asian American, and Pacific Islander children, and children living in lower income neighborhoods.
The articles featured in this supplement examine a diverse range of issues and policies that influence young people's food and physical activity landscapes, with special attention to populations that are most vulnerable to the obesity epidemic. Johnson et al [17] analyzed school nutrition policies from 64 ethnically and economically diverse middle schools in Washington state to determine their impact on student consumption of sugar-sweetened beverages. These beverages were available for student purchase in 47 of the 64 schools examined, and the study found that exposure was significantly associated with student consumption. Overall, the findings also indicated that the stronger the school policy limiting the availability of sugar-sweetened beverages, the smaller the proportion of students drinking them at school.
Barroso et al [18] assessed the impact of Texas Senate Bill 42, which required students in that state's public middle schools to participate in 30
minutes of structured physical activity daily. Overall, schools met or exceeded the requirement. At the state level, schools reported an average of 4.7 days of physical education class per week, with an average class length of 53minutes. According to cross-sectional samples of eighth-grade students living in Texas–Mexico border areas, students' weekly participation in physical education increased to 3.7 days from 2.0 days, after the requirement was implemented. These data, the authors note, add to a growing body of evidence showing that school policies can be an effective strategy for addressing childhood obesity.
Ries et al [19] evaluated park use among 329 high school students in Baltimore and found that teens' personal perceptions of parks mattered more than objective measures of park availability. The teens used parks more for physical activity when they perceived the parks to be available, of high quality and used by their friends. In general, African Americans and girls were less likely to use parks. The authors suggest that efforts to promote park use among urban youths include the marketing of existing facilities and a focus on increased social support from peers and family. Urban African American students comprised 69% of this study sample; this is one of few studies to evaluate the impact of the environment on physical activity in this population, which has a disproportionately low level of physical activity.
These articles and other studies in this special issue offer significant contributions to the field of childhood obesity prevention. We are grateful to the authors for their pursuit of the most promising approaches to increase physical activity and healthy eating, especially among youths hardest hit by the crisis. Many of these teams also evaluate policy and program changes already taking place at local and state levels to determine whether they are effective and worthy of wider implementation. Only through such sound and sustained research efforts will solutions emerge that will set us on the right course to reversing our country's childhood obesity epidemic.
FULL TEXT