Parents should promote healthful eating behaviors and regular physical activity for their children.
To implement this recommendation parents can:
• Choose exclusive breastfeeding as the method for feeding in- fants for the first four to six months of life
• Provide healthful food and beverage choices for children by carefully considering nutrient quality and energy density
• Assist and educate children in making healthful decisions re- garding types of foods and beverages to consume, how often, and in what portion size
• Encourage and support regular physical activity
• Limit children’s television viewing and other recreational screen time to less than two hours per day
• Discuss weight status with their child’s health-care provider and monitor age- and gender-specific BMI percentile
• Serve as positive role models for their children regarding eating and physical-activity behaviors
CONFRONTING THE CHILDHOOD OBESITY EPIDEMIC The committee acknowledges, as have many other similar efforts, that obesity prevention is a complex issue, that a thorough understanding of the causes and determinants of the obesity epidemic is lacking, and that progress will require changes not only in individual and family behaviors but also in the marketplace and the social and built environments (Box ES-2). As the nation focuses on obesity as a health problem and begins to address the societal and cultural issues that contribute to excess weight, poor food choices, and inactivity, many different stakeholders will need to make diffi- cult trade-offs and choices. However, as institutions, organizations, and individuals across the nation begin to make changes, societal norms are
16 PREVENTING CHILDHOOD OBESITY
likely to change as well; in the long term, we can become a nation where proper nutrition and physical activity that support energy balance at a healthy weight will become the standard.
Recognizing the multifactorial nature of the problem, the committee deliberated on how best to prioritize the next steps for the nation in pre- venting obesity in children and youth. The traditional method of prioritiz- ing recommendations of this nature would be to base these decisions on the strength of the scientific evidence demonstrating that specific inter- ventions have a direct impact on reducing obesity prevalence and to order the evidence-based approaches based on the balance between potential benefits and associated costs including potential risks. However, a robust evidence base is not yet available. Instead, we are in the midst of compiling that much-needed evidence at the same time that there is an urgent need to respond to this epidemic of childhood obesity. Therefore, the committee used the best scientific evidence available—including studies with obesity as the outcome measure and studies on improving dietary behaviors, increas- ing physical activity levels, and reducing sedentary behaviors, as well as years of experience and study on what has worked in addressing similar public health challenges—to develop the recommendations presented in this report.
As evidence was limited, yet the health concerns are immediate and warrant preventive action, it is an explicit part of the committee’s recom- mendations that all the actions and initiatives include evaluation efforts to help build the evidence base that continues to be needed to more effectively fight this epidemic.
From the ten recommendations presented above, the committee has identified a set of immediate steps based on the short-term feasibility of the actions and the need to begin a well-rounded set of changes that recognize the diverse roles of multiple stakeholders (Table ES-1). In discussions and interactions that have already begun and will follow with this report, each
BOX ES-2
Summary of Findings and Conclusions
• Childhood obesity is a serious nationwide health problem requiring urgent at- tention and a population-based prevention approach so that all children may grow up physically and emotionally healthy.
• Preventing obesity involves healthful eating behaviors and regular physical activity—with the goal of achieving and maintaining energy balance at a healthy weight.
• Individual efforts and societal changes are needed. Multiple sectors and stake- holders must be involved.
EXECUTIVE SUMMARY 17 community and stakeholder group will determine their own set of priorities and next steps. Furthermore, action is urged for all areas of the report’s recommendations, as the list in Table ES-1 is only meant as a starting point.
The committee was also asked to set forth research priorities. There is still much to be learned about the causes, correlates, prevention, and treat- ment of obesity in children and youth. Because the focus of this study is on prevention, the committee concentrated its efforts throughout the report on identifying areas of research that are priorities for progress toward prevent- ing childhood obesity. The three research priorities discussed throughout the report are:
• Evaluation of obesity prevention interventions—The committee en- courages the evaluation of interventions that focus on preventing an in- crease in obesity prevalence, improving dietary behaviors, increasing physi- cal activity levels, and reducing sedentary behaviors. Specific policy, environmental, social, clinical, and behavioral intervention approaches should be examined for their feasibility, efficacy, effectiveness, and sustainability. Evaluations may be in the form of randomized controlled trials and quasi-experimental trials. Cost-effectiveness research should be an important component of evaluation efforts.
• Behavioral research—The committee encourages experimental re- search examining the fundamental factors involved in changing dietary behaviors, physical activity levels, and sedentary behaviors. This research should inform new intervention strategies that are implemented and tested at individual, family, school, community, and population levels. This would include studies that focus on factors promoting motivation to change be- havior, strategies to reinforce and sustain improved behavior, identification and removal of barriers to change, and specific ethnic and cultural influ- ences on behavioral change.
• Community-based population-level research—The committee en- courages experimental and observational research examining the most im- portant established and novel factors that drive changes in population health, how they are embedded in the socioeconomic and built environ- ments, how they impact obesity prevention, and how they affect society at large with regard to improving nutritional health, increasing physical activ- ity, decreasing sedentary behaviors, and reducing obesity prevalence.
The recommendations that constitute this report’s action plan to pre- vent childhood obesity commence what is anticipated to be an energetic and sustained effort. Some of the recommendations can be implemented immediately and will cost little, while others will take a larger economic investment and require a longer time for implementation and to see the benefits of the investment. Some will prove useful, either quickly or over the
18 PREVENTING CHILDHOOD OBESITY
longer term, while others will prove unsuccessful. Knowing that it is impos- sible to produce an optimal solution a priori, we more appropriately adopt surveillance, trial, measurement, error, success, alteration, and dissemina- tion as our course, to be embarked on immediately. Given that the health of today’s children and future generations is at stake, we must proceed with all due urgency and vigor.
EXECUTIVE SUMMARY 19 TABLE ES-1 Immediate Steps
Federal government • Establish an interdepartmental task force and coordinate federal actions
• Develop nutrition standards for foods and beverages sold in schools
• Fund state-based nutrition and physical-activity grants with strong evaluation components
• Develop guidelines regarding advertising and marketing to children and youth by convening a national conference
• Expand funding for prevention intervention research, experimental behavioral research, and community- based population research; strengthen support for surveillance, monitoring, and evaluation efforts Industry and media • Develop healthier food and beverage product and
packaging innovations
• Expand consumer nutrition information
• Provide clear and consistent media messages
State and local • Expand and promote opportunities for physical activity governments in the community through changes to ordinances,
capital improvement programs, and other planning practices
• Work with communities to support partnerships and networks that expand the availability of and access to healthful foods
Health-care professionals • Routinely track BMI in children and youth and offer appropriate counseling and guidance to children and their families
Community and nonprofit • Provide opportunities for healthful eating and physical organizations activity in existing and new community programs,
particularly for high-risk populations
State and local education • Improve the nutritional quality of foods and beverages authorities and schools served and sold in schools and as part of school-related
activities
• Increase opportunities for frequent, more intensive and engaging physical activity during and after school
• Implement school-based interventions to reduce children’s screen time
• Develop, implement, and evaluate innovative pilot programs for both staffing and teaching about wellness, healthful eating, and physical activity Parents and families • Engage in and promote more healthful dietary intakes
and active lifestyles (e.g., increased physical activity, reduced television and other screen time, more healthful dietary behaviors)
21
Introduction
AN EPIDEMIC OF CHILDHOOD OBESITY
C
hildren’s health in the United States has improved dramatically over the past century. Vaccines targeting previously common child- hood infections—such as measles, polio, diphtheria, tetanus, ru- bella, and Haemophilus influenza—have nearly eliminated these scourges.Through the widespread availability of potable water, improved sanitation, and antibiotics, diarrheal diseases and infectious diseases such as tuberculo- sis and pneumonia have diminished in frequency and as primary causes of infant and child deaths in the United States (CDC, 1999). Pervasive food scarcity and essential vitamin and mineral deficiencies have largely disap- peared in the U.S. population (IOM, 1991; Kessler, 1995). The net result is that infant mortality has been lowered by over 90 percent, contributing to the substantial increase in life expectancy—more than 30 years—since 1900 (CDC, 1999). Innovations such as seatbelts, child car seats, and bike hel- mets, meanwhile, have contributed to improved children’s safety, and fluo- ridation of municipal drinking water has enhanced child and adolescent dentition (CDC, 1999).
Given this steady trajectory toward a healthier childhood and healthier children, we begin the 21st century with a startling setback—an epidemic1
1
1The term “epidemic” is used in reference to childhood obesity as there have been an unexpected and excess number of cases on a steady increase in recent decades.
22 PREVENTING CHILDHOOD OBESITY
of childhood obesity. This epidemic is occurring in boys and girls in all 50 states, in younger children as well as in adolescents, across all socioeco- nomic strata, and among all ethnic groups—though specific subgroups, including African Americans, Hispanics, and American Indians, are dispro- portionately affected (Ogden et al., 2002; Caballero et al., 2003). At a time when we have learned that excess weight has significant and troublesome health consequences, we nevertheless see our population, in general, and our children, in particular, gaining weight to a dangerous degree and at an alarming rate.
The increasing prevalence of childhood obesity throughout the United States has led policy makers to rank it as a critical public health threat for the 21st century (Koplan and Dietz, 1999; Mokdad et al., 1999, 2000;
DHHS, 2001). Over the past three decades since the 1970s, the prevalence of childhood obesity (defined in this report as a gender- and age-specific body mass index [BMI] at or above the 95th percentile on the 2000 CDC BMI charts) has more than doubled for preschool children aged 2 to 5 years and adolescents aged 12 to 19 years, and it has more than tripled for children aged 6 to 11 years (see Chapter 2; Ogden et al., 2002). Approxi- mately nine million American children over 6 years of age are already considered obese. These trends mirror a similar profound increase in U.S.
adult obesity and co-morbidities over a comparable time frame, as well as a concurrent rise in the prevalence of childhood and adult obesity and related chronic diseases internationally, in developed and developing countries alike (WHO, 2002, 2003; Lobstein et al., 2004).
IMPLICATIONS FOR CHILDREN AND SOCIETY AT LARGE Many of us consider our weight and height as personal statistics, pri- marily our own, and occasionally our physician’s concern. Our weight is something we approximate on forms and applications requiring this infor- mation. Body size has been a cosmetic issue rather than a health issue throughout most of human history, but scientific study has changed this view. One’s aesthetic preference for a lean versus a plump body type may be related to personal taste, cultural and social norms, and association of body type with wealth or well-being. However, the implications of a wholesale increase in BMIs are increasingly becoming a public health problem. Thus, we need to acknowledge the sensitive personal dimension of height and weight, while also viewing weight as a public health issue, especially as the weight levels of children, as a population, are proceeding on a harmful upward trajectory.
The as yet unabated epidemic of childhood obesity has significant rami- fications for children’s physical health, both in the immediate and long term, given that obesity is linked to several chronic disease risks. In a
INTRODUCTION 23 population-based sample, approximately 60 percent of obese children aged 5 to 10 years had at least one physiological cardiovascular disease (CVD) risk factor—such as elevated total cholesterol, triglycerides, insulin, or blood pressure—and 25 percent had two or more CVD risk factors (Freedman et al., 1999).
The increasing incidence of type 2 diabetes in young children (previ- ously known as adult onset diabetes) is particularly startling. For individu- als born in the United States in 2000, the lifetime risk of being diagnosed with diabetes at some point in their lives is estimated at 30 percent for boys and 40 percent for girls if obesity rates level off (Narayan et al., 2003).2 The estimated lifetime risk for developing diabetes is even higher among ethnic minority groups at birth and at all ages (Narayan et al., 2003). Type 2 diabetes is rapidly becoming a disease of children and adolescents. In case reports limited to the 1990s, type 2 diabetes accounted for 8 to 45 percent of all new childhood cases of diabetes—in contrast with fewer than 4 percent before the 1990s (Fagot-Campagna et al., 2000). Young people are also at risk of developing serious psychosocial burdens related to being obese in a society that stigmatizes this condition, often fostering shame, self-blame, and low self-esteem that may impair academic and social func- tioning and carry into adulthood (Schwartz and Puhl, 2003).
The growing obesity epidemic in children, and in adults, affects not only the individual’s physical and mental health but carries substantial direct and indirect costs for the nation’s economy as discrimination, eco- nomic disenfranchisement, lost productivity, disability, morbidity, and pre- mature death take their tolls (Seidell, 1998). States and communities are obliged to divert resources to prevention and treatment, and the national health-care system is burdened with the co-morbidities of obesity such as type 2 diabetes, hypertension, CVD, osteoarthritis, and cancer (Ebbeling et al., 2002).
The obesity epidemic may reduce overall adult life expectancy (Fontaine et al., 2003) because it increases lifetime risk for type 2 diabetes and other serious chronic disease conditions (Narayan et al., 2003), thereby poten- tially reversing the positive trend achieved with the reduction of infectious diseases over the past century. The great advances of genetics and other biomedical discoveries could be more than offset by the burden of illness, disability, and death caused by too many people eating too much and moving too little over their lifetimes.
2These projections are based on data on the lifetime risk of diagnosed diabetes and do not account for undiagnosed cases. The data do not allow for differentiation between type 1 and type 2 diabetes. However, the major form of diabetes in the U.S. population is type 2, which accounts for an estimated 95 percent of diabetes cases (Narayan et al., 2003).
24 PREVENTING CHILDHOOD OBESITY
Aside from the statistics, we can see the evidence of childhood obesity in our community schoolyards, in shopping malls, and in doctors’ offices.
There are confirmatory journalistic reports of the epidemiologic trends in weight—from resizing of clothing to larger coffins to more spacious easy chairs to the increased need for seatbelt extenders. These would be of passing interest and minimal importance were it not for the considerable health implications of this weight gain for both adults and children. For example, compared with adults of normal weight, adults with a BMI of 40 or more have a seven-fold increased risk for diagnosed diabetes (Mokdad et al., 2003). Indeed, the obesity epidemic places at risk the long-term welfare and readiness of the U.S. military services by reducing the pool of individu- als eligible for recruitment and decreasing the retention of new recruits.
Nearly 80 percent of recruits who exceed the military accession weight-for- height standards at entry leave the military before they complete their first term of enlistment (IOM, 2003).
What might our population look like in the year 2025 if we continue on this course? In a land of excess calories ingested and insufficient energy expended, the inevitable scenario is a continued increase in average body size and an altered concept of what is “normal.” Americans with a BMI below 30 will be considered small and obesity will no longer be newswor- thy but accepted as the social norm.
While the existence and importance of the increase in the population- wide obesity problem are no longer debated, we are still mustering the determination to forge effective solutions. We must remind ourselves that social changes to transform public perceptions and behaviors regarding seatbelt use, smoking cessation, breastfeeding, and recycling would have sounded unreasonable just a few decades ago (Economos et al., 2001), yet we have acted vigorously and with impressive results. How to proceed similarly in meeting the formidable childhood obesity challenge is the focus of this Institute of Medicine (IOM) report.
The 19-member IOM committee was charged with developing a pre- vention-focused action plan to decrease the prevalence of obesity in chil- dren and youth in the United States. The primary emphasis of the committee’s task was on examining the behavioral and cultural factors, social constructs, and other broad environmental factors involved in child- hood obesity and identifying promising approaches for prevention efforts.
This report presents the committee’s recommendations for many different segments of society from federal, state, and local governments (Chapter 4), to industry and media (Chapter 5), local communities (Chapter 6), schools (Chapter 7), and parents and families (Chapter 8).
INTRODUCTION 25 CONTEXTS FOR ACTION
Investigating the causes of childhood obesity, determining what to do about them, and taking appropriate action must address the variables that influence both eating and physical activity. Seemingly straightforward, these variables result from complex interactions across a number of relevant social, economic, cultural, environmental, and policy contexts.
U.S. children live in a society that has changed dramatically in the three decades over which the obesity epidemic has developed. Many of these changes, such as both parents working outside the home, often affect deci- sions about what children eat, where they eat, how much they eat, and the amount of energy they expend in school and leisure time activities (Ebbeling et al., 2002; Hill et al., 2003).
Other changes, such as the increasing diversity of the population, influ- ence cultural views and marketing patterns. Lifestyle modifications, in part the result of media usage and content together with changes in the physical design of communities, affect adults’ and children’s levels of physical activ- ity. Many of the social and cultural characteristics that the U.S. population has accepted as a normal way of life may collectively contribute to the growing levels of childhood obesity. The broad societal trends that impact weight outcomes are complex and clearly multifactorial. With such societal changes, it is difficult to tease out the quantitative and qualitative role of individual contributing factors. While distinct causal relationships may be difficult to prove, the dramatic rise in childhood obesity prevalence must be viewed within the context of these broad societal changes.
An understanding of these contexts, particularly regarding their poten- tial to be modified and how they may facilitate or impede development of a comprehensive obesity prevention strategy, is therefore essential. This next section provides a useful background to understand the multidimensional nature of the childhood obesity epidemic.
Lifestyle and Demographic Trends
The interrelated areas of family life, ethnic diversity, eating patterns, physical activity, and media use—discussed below—are all aspects of soci- etal change that must be considered. Singly and in concert, the trends in these areas will strongly influence prospects for preventive and corrective measures.
Family Life
The changing context of American families includes several distinct trends such as the shifting role of women in society, delayed marriage,