Overweight has reached epidemic proportions in the United States and has myriad associated comorbidities. Both small and large weight increases are associated with increased disease risk.1,2 In 2001, the Surgeon General's call for action on obesity indicated $117 billion annually in health care costs alone could be attributed to obesity and obesity-related complications.3 Only smoking contributes more to total mortality in the United States.4
This article focuses on social and ethnic aspects of overweight It should be noted that the terms used throughout the paper are broad characterizations of ethnic groups. It is understood that ethnic categories contain significant diversity. For example, "blacks" include those who may have come from different cultures of Africa and the Caribbean. The Hispanic/Latino populations in the US are Mexican-American, Puerto Rican, Central American, and South American. All have different dietary habits and acculturation periods to the US of several generations.
OVERWEIGHT IN THE US POPULATION
The health problems associated with overweight are strikingly apparent in minority populations, most notably among the blacks and Latinos who comprise the two largest minority groups in this country. Regrettably, these obesityrelated ethnic differences in risk factors are evident as early as ages 6 to 9.5
A combination of ethnic predisposition, excess caloric intake, and inadequate physical activity contributes to the onset and maintenance of overweight. The rapid rise in rates of overweight during the past 2 decades emphasizes the importance of environmental change. Researchers and health care providers are challenged to understand reasons behind the high rates of chronic disorders in minority communities, and to study whemer the prevention of overweight in childhood will favorably affect the variety of chronic diseases associated with increasing overweight. This focus on early prevention is particularly important in view of how hard it is to achieve sustained weight loss.
The definitions of overweight and current patterns in children are reviewed in this issue by Binns and Ariza (see page xxx). For the entire US population. 15.3% of children 6 to 1 1 years old and 15.5% of youths 12 to 19 years old are overweight. These rates are as much as twice as high among minority children and adolescents.7 The prevalence of overweight among black and Latino women is 64.5% and 56.8%, respectively, and children with overweight parents are more likely to become overweight themselves, putting minority children at increased risk. However, there are no significant differences among ethnic groups in the prevalence of overweight between the ages of 2 and 5.7 Therefore, a mandate exists to prevent and control overweight among younger minority children. There is a critical need to intervene early and comprehensively. Prevention and control of overweight in young children, particularly minority children, must expand beyond the individual and include the family, school, and community in which the child develops.
ENERGY INTAKE VERSUS ENERGY EXPENDITURE
Excessive weight gain develops from an energy imbalance between energy intake and energy expenditure. Fat intake is an important contributor to energy balance.8 There is evidence that body fat storage occurs at a greater rate when excess energy comes from fat than when it comes from carbohydrates or protein.7 Dietary observations of Mexican-Americans reveal high-fat, lowfiber diets.8 Specifically, MexicanAmerican boys consume more saturated fat as a percentage of energy intake than children of other ethnicities.
Some data suggest the diets of overweight children have a higher proportion of fat than those of normal-weight children. Several recent longitudinal studies revealed higher levels of dietary fat intake are associated with a greater increase in weight among children.9 This suggests low-fat, high-fiber diets may lead to weight loss or control and protect against overweight and cardiovascular disease. Lower levels of physical activity, a higher-fat diet, and impaired glucose tolerance are all more prevalent in minority populations, placing minority children at further increased risk.10
Individuals' efforts to modify thenown health practices are often impeded by a combination of economic, social, and cultural constraints. It is important to recognize how dramatically our communities' dietary patterns have changed during the past 50 years. For example, soft drink consumption has increased from 100 12-ounce cans per year per person in the 1940s to nearly 600 cans per person in 2000s.11 The increase has been most marked among children and adolescents. Although no clear relationship has been established to suggest that sugar contributes to weight gain, there is some evidence that liquid sugar may be less well regulated than energy consumed in liquid form.12
Our communities are also replete with outlets for high-fat, energy-dense foods. Many foods mat are now advertised as low-fat, occurring in response to the documented need for Americans to lower fat intake, are not low-calorie. Some people may be consuming less fat yet more overall calories.
In addition, Americans now eat away from home more often, and restaurant food is higher in energy and fat when compared to foods eaten at home. Foods eaten away from home also often result in higher energy and fat intake because of increasingly larger portions in these settings.13·14 For example, an average fast food hamburger weighing approximately 1 ounce in 1957 now weighs approximately 6 ounces.14 It is likely that increased portion sizes contribute to increased energy intake, especially because there has not been an equivalent increase in energy expenditure.
Television and Video Games
Other than time spent sleeping, children in the US spend more time watching television and playing video games than anything else.15·16 This increases the risk of overweight, especially when combined with eating.17 A recent study conducted with sixth and seventh grade students found watching television and the number of soft drinks consumed were significantly associated with obesity, and that Latinos spent more time watching television and consumed more soft drinks than white children.18 Another recent study found primetime television shows oriented to black audiences had significantly more food commercials, most of which were for highcaloric, low-nutrient foods.19 This study also noted that the characters on these shows were more often overweight, reinforcing the concept that overweight is more pervasive and accepted in minority populations.
Community-specific patterns of activity are important. Data indicate minority children and adults may be less likely to engage in sufficient physical activity. For example, adult data from the National Health Interview Survey in 1998 found 52% of black women engaged in no leisure-time physical activity.2 These observations are disturbing because childhood physical activity patterns are believed to persist into adulthood. Time performing recreational activity is related to body fat and aerobic fitness, as well as weight gain in young children.20 Latino preschool children have been found to perform less activity than white children at home.21
Family, school, and community environments are important in providing structure for appropriate levels of physical activity in young children. Studies show that children are more physically active when their parents are active, as well as when they receive direct parental encouragement.21 Unfortunately, given the lower rates of physical activity among minority adults, there is less modeling of a physically active lifestyle.
Social and economic factors play a role in the lower levels of physical activity among minority populations. Research shows that less educated, lower socioeconomic status (SES), and obese individuals are less likely to exercise than their more educated, higher SES, and normal-weight counterparts.22
Because a greater percentage of black and Latino women are obese and economically disadvantaged, it is likely that they face numerous barriers to achieving higher activity levels.
The Centers for Disease Control and Prevention (CDC) encourages the development of comprehensive school and community programs that promote physical activity among children, which is often more challenging in minority communities. In a recent survey, parents in minority populations were twice as likely as white parents to report that that their neighborhoods were unsafe.23 Studies show physical activity is positively related to safe access to facilities and equipment. This information may help explain the lower levels of physical activity in minority populations and tfie higher prevalence of television watching among black and Latino children.
Importance of the School Setting
Recent decreases in mandatory physical education programs and in walking contribute tol rising rates of overweight. A recent poll found 71% of parents of schoolaged children walked or biked to school when they were young, but only 18% of their children now walk or bike to school.24 In minority communities where safety is often an issue, few people walk or bicycle to reach a destination. Recent community-wide and national efforts to promote walking and bicycling have been put forth by the CDC such as the Walk to School Program. The Objectives of Healthy People 20 10 -initiative challenges families to increase the proportion of children's trips to school less than or equal to 1 mile made by walking from 31% to 50%; and increase the proportion of children's trips to school less than or equal to 2 miles made by bicycling from 2.4% to 5%.
In this way and others, school environments are an important avenue for the intervention, prevention, and control of overweight in children.25 Most US children are enrolled in school, and unlike most other settings, schools provide continuous exposure for the children. Some advantages of school-based obesity prevention programs include no cost to families, inclusion of lowincome and ethnic minority families, and inclusion of school food services.
Most school-based interventions do not target obesity as a primary goals, but focus more broadly on healthy eating and exercise.25 For example, the primary goals of Healthy Start, a 3-year intervention trial of 3- and 4-year-old children enrolled in nine Head Start centers, are the reduction of blood cholesterol and dietary fat and an increase in nutrition knowledge.26 Also, the Child and Adolescent trial for Cardiovascular Health (CATCH), which included 56 intervention schools and 40 control schools, was designed to assess the outcome of health behaviors focusing on the elementary school environment, classroom curricula, and a home program for the primary prevention of cardiovascular disease. Results showed the CATCH program was able to modify the fat content of school lunches, to increase moderate to vigorous activity, and to improve eating and physical activity behavior in children during 3 academic years. However, there were no significant effects in the intervention school related to obesity after 3 years.27 Recently, the PATHWAYS program, an obesity-prevention intervention for third-grade American Indian children, was completed. It showed changes in dietary fat consumption, but again no effect on weight.27
Currently, more than 26 million children participate in tlie National School Lunch Program.28 Beginning in 1996, schools participating in the United States Department of Agriculture's national school-meals program were required to serve meals in accordance with the Dietary Guidelines for Americans.29 Across the country, school meals are becoming healthier, but opportunities for children to over-consume calories and fat remain because the overall fat content of the food often still exceeds recommended amounts.30
In minority populations, those who do not maintain normal weight outnumber those who do; thus, overweight is often the community norm. Compared to many white populations, minority populations are transitioning from poverty, food scarcity, and jobs that require significant amounts of energy expenditure.31 This may mean food and activity habits of both black and Latino populations may have been developed during a more physically-active era. Caloric restriction and leisure-time physical activity are not routine in minority communities. In these communities, there are often few supermarkets that carry fresh produce, many fast food establishments and small grocery stores that sell high-fat, energy-dense foods, and high neighborhood crime rates that discourage outdoor activities and limit safe places for walking and bicycling, including school routes.
Although specific dietary and activity behaviors related to weight control ultimately are undertaken by individuals, our current environment makes such individual choices difficult when it contains substantial barriers to establishing healthy lifestyles. Substantial environmental changes need to be made, especially in minority communities.
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