Healthy People 2010¾ Conference Edition

19
Nutrition
and Overweight

Co-Lead Agencies: Food and Drug Administration;
National Institutes of Health

Contents

Goal

Overview

Issues and Trends

Disparities

Opportunities

Interim Progress Toward Year 2000 Objectives

Healthy People 2010—Summary of Objectives

Healthy People 2010 Objectives

Weight Status and Growth

Food and Nutrient Consumption

Iron Deficiency and Anemia

Schools, Worksites, and Nutrition Counseling

Food Security

Related Objectives From Other Focus Areas

Terminology

References

Goal

Promote health and reduce chronic disease associated with diet and weight.

Overview

Issues and Trends

Nutrition is essential for growth and development, health, and well-being. Behaviors to promote health should start early in life with breastfeeding¹ and continue through life with the development of healthful eating habits. Nutritional, or dietary, factors contribute substantially to the burden of preventable illnesses and premature deaths in the United States.² Indeed, dietary factors are associated with 4 of the 10 leading causes of death: coronary heart disease (CHD), some types of cancer, stroke, and type 2 diabetes.³ These health conditions are estimated to cost society over $200 billion each year in medical expenses and lost productivity.⁴ Dietary factors also are associated with osteoporosis, which affects more than 25 million persons in the United States and is the major underlying cause of bone fractures in postmenopausal women and elderly persons.⁵

Many dietary components are involved in the relationship between nutrition and health. A primary concern is consuming too much saturated fat and too few vegetables, fruits, and grain products that are high in complex carbohydrates, dietary fiber, vitamins and minerals, and other substances conducive to health. The 1995 Dietary Guidelines for Americans recommend that, to stay healthy, persons aged 2 years and older should eat a variety of foods; maintain or improve one’s weight by balancing food intake with physical activity; choose a diet that is plentiful in grain products, vegetables, and fruits, moderate in salt, sodium, and sugars, and low in fat, saturated fat, and cholesterol; and, if consuming alcoholic beverages, do so in moderation.⁶ The Food Guide Pyramid, introduced in 1992, is an educational tool that conveys recommendations about the number of servings from different food groups each day and other principles of the Dietary Guidelines for Americans.⁷

demonstrated by an objective in this focus area. In addition, in recent years there has been a concerted effort to increase the folic acid intake of females of childbearing age through fortification and other means to reduce the risk of neural tube defects.^{10, 11} (See Focus Area 16. Maternal, Infant, and Child Health.)

In general, however, excesses and imbalances of some food components in the diet have replaced once commonplace nutrient deficiencies. Unfortunately, there has been an alarming increase in the number of overweight and obese persons.^{12, 13} Overweight results when a person eats more calories from food (energy) than he or she expends, for example, through physical activity. This balance between energy intake and output is influenced by metabolic and genetic factors as well as behaviors affecting dietary intake and physical activity; environmental, cultural, and socioeconomic components also play a role.

When a body mass index (BMI) cut-point of 25 is used, nearly 55 percent of the U.S. adult population was defined as overweight or obese in 1988-94, compared to 46 percent in 1976-80.^{12, 14, 15} In particular, the proportion of adults defined as obese by a BMI 30 or greater has increased from 14.5 percent to 22.5 percent.¹² A similar increase in overweight and obesity also has been observed in children above age 6 years in both genders and in all population groups.¹⁶

Many diseases are associated with overweight and obesity. Persons who are overweight or obese are at increased risk for high blood pressure, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and some types of cancer. The health outcomes related to these diseases, however, often can be improved through weight loss or, at a minimum, no further weight gain. Total costs (medical costs and lost productivity) attributable to obesity alone amounted to an estimated $99 billion in 1995.¹⁷

Disparities

Disparities in health status indicators and risk factors for diet-related disease are evident in many segments of the population based on gender, age, race and ethnicity, and income. For example, overweight and obesity are observed in all population groups, but obesity is particularly common among Hispanic, African American, Native American, and Pacific Islander women. Furthermore, despite concerns about the increase in overweight and certain excesses in American diets, segments of the population also suffer from undernutrition, including persons who are socially isolated and poor. Over the years, the recognition of the consequences of food insecurity (limited access to safe, nutritious food) has led to the development of national measures and surveys to evaluate food insecurity and hunger and to the ability to assess disparities among different population groups. With food security and other measures of undernutrition, such as growth retardation and iron deficiency, disparities are evident based not only on income but also on race and ethnicity.

In addition, there are concerns about the nutritional status of persons in hospitals, nursing homes, convalescent centers, and institutions; persons with disabilities, including physically, mentally, and developmentally disabled persons in community settings; children in child care facilities; persons living on reservations; persons in correctional facilities; and persons who are homeless. National data about these population groups are currently unavailable or limited. Data also are insufficient to target the fastest growing segment of the population, the old and very old who live independently.

Opportunities

Establishing healthful dietary and physical activity behaviors needs to begin in childhood. Educating school-aged children about nutrition is important to help establish healthful eating habits early in life.^{18, 19} Research suggests that parents who understand proper nutrition can help preschoolers choose healthful foods, but they have less influence on the choices of school-aged children.²⁰ Thus, the impact of nutrition education on health may be more effective if targeted directly at school-aged children. Unfortunately, a survey done in 1994 showed that only 69 percent of States and 80 percent of school districts required nutrition education for students in at least some grades from kindergarten through 12th grade.²¹

A well-designed curriculum that effectively addresses essential nutrition education topics can increase students’ knowledge about nutrition, help shape appropriate attitudes, and help develop the behavioral skills students need to plan, prepare, and select healthful meals and snacks.^{18, 22, 23} Curricula that encourage specific, healthful eating behaviors and provide students with the skills needed to adopt and maintain those behaviors have led to favorable changes in student dietary behaviors and cardiovascular disease risk factors.^{18, 22, 23} In order to enhance the effectiveness of these lessons, however, nutrition course work should be part of the core curriculum for the professional preparation of teachers of all grades and should be emphasized in continuing education activities for teachers.

Topics considered to be essential at the elementary, middle and junior high, and senior high school levels include using the Food Guide Pyramid; learning the benefits of healthful eating; making healthful food choices for meals and snacks; preparing healthy meals and snacks; using food labels; eating a variety of foods; eating more fruits, vegetables, and grains; eating foods low in saturated fat and total fat more often; eating more calcium-rich foods; balancing food intake and physical activity; accepting body size differences; and following food safety practices.^{18, 24} In addition, the following topics are considered to be essential at the middle/junior and senior high school levels: the Dietary Guidelines for Americans; eating disorders; healthy weight maintenance; influences on food choices such as families, culture, and media; and goals for dietary improvement.¹⁸

Nutrition education should be taught as part of a comprehensive school health education program, and essential nutrition education topics should be integrated into science and other curricula to reinforce principles and messages learned in the health units. Nutrition education is addressed within a school health education objective. (See Focus Area 7. Educational and Community-Based Programs.) In addition, students must have access to healthful food choices to further enhance the likelihood of adopting healthful dietary practices. For these reasons, monitoring students’ eating practices at school is important.

Although health promotion efforts should begin in childhood, they need to continue throughout adulthood. In particular, public education about the long-term health consequences and risks associated with overweight and how to achieve and maintain a healthy weight is necessary. While many persons attempt to lose weight, studies show that within 5 years a majority of them regain the weight.²⁵ To maintain weight loss, healthful dietary habits must be coupled with decreased sedentary behavior and increased physical activity and become permanent lifestyle changes. (See Focus Area 22. Physical Activity and Fitness.) Additionally, changes in the physical and social environment may help persons maintain the necessary long-term lifestyle changes for both diet and physical activity.

Policymakers and program planners at the national, State, and community levels can and should provide important leadership in fostering healthful diets and physical activity patterns among Americans. The family and others, such as health care practitioners, schools, worksites, institutional food services and the media, can play a key role in this process. For example, registered dietitians and other qualified health care practitioners can improve health outcomes through efforts focused on nutrition screening, assessment, and primary and secondary prevention.

Food-related businesses can also help consumers achieve healthful diets by providing nutrition information for foods purchased in supermarkets, fast-food outlets, restaurants, and carryout operations. For example, the introduction of a new food label in 1993 has resulted in nutrition information on most processed packaged foods, along with credible health and nutrient content claims and standardized serving sizes.²⁶ While efforts were made in the 1990s to increase the availability of nutrition information, reduced-fat foods, and other healthful food choices in supermarkets, significant challenges remain on these fronts for away-from-home foods purchased at food service outlets. The importance of addressing these challenges is suggested by recent data indicating that nearly 40 percent of a family’s food budget is spent on away-from-home food, including food from restaurants and fast-food outlets.²⁷ One analysis found that away-from-home foods are generally higher in saturated fat, total fat, cholesterol, and sodium and lower in dietary fiber, iron, and calcium than at-home foods.²⁷ Away-from-home sites include restaurants, fast-food outlets, school cafeterias, and vending machines. This study also suggested that persons either eat larger amounts when they eat out, eat higher calorie foods, or both.

Many of the 2010 objectives that address nutrition and overweight in the United States measure in some way the Nation’s progress toward implementing the recommendations of the Dietary Guidelines for Americans. The recommendations for food and nutrient intake are not intended to be met every day but rather on average over a span of time. Although the 2010 dietary intake objectives address the proportion of the population that consumes a specified level of certain foods or nutrients, it is also important to track and report the average amount eaten by different population groups to help interpret progress on these objectives. Other objectives target aspects of undernutrition, including iron deficiency, growth retardation, and food security.

In summary, several actions are recognized as fundamental in achieving the 2010 objectives:

§ Improving accessibility of nutrition information, nutrition education, nutrition counseling and related services, and healthful foods in a variety of settings and for all subpopulations.

§ Focusing on preventing chronic disease associated with diet and weight, beginning in youth.

§ Strengthening the link between nutrition and physical activity in health promotion.

§ Maintaining a strong national program for basic and applied nutrition research to provide a sound science base for dietary recommendations and effective interventions.

§ Maintaining a strong national nutrition monitoring program to provide accurate, reliable, timely, and comparable data to assess status and progress and to be responsive to unmet data needs and emerging issues.

§ Strengthening State and community data systems to be responsive to the data users at these levels.

§ Building and sustaining broad-based initiatives and commitment to these objectives by public and private sector partners at the national, State, and local levels.

Interim Progress Toward Year 2000 Objectives

Of the 27 nutrition objectives, targets for 5 have been met, including 2 related to the availability of reduced-fat foods and prevalence of growth retardation.^{9, 28} The majority of the objectives have shown some progress, including those related to total fruit, vegetable, and grain product intake and total fat and saturated fat intake; availability of nutrition labeling on foods; breastfeeding; nutrition education in schools; and availability of worksite nutrition and weight management programs. For certain other objectives, such as consumer actions to reduce salt intake and home-delivered meals to elderly persons, there has been little or no progress. And for others, such as intake of calcium-rich food and overweight and obesity, movement has been away from the targets. In particular, the proportion of adults and children who are overweight or obese has increased substantially, and this represents one of the biggest challenges for Healthy People 2010.

Note: Unless otherwise noted, data are from Centers for Disease Control and Prevention, National Center for Health Statistics, Healthy People 2000 Review, 1998-99.

Healthy People 2010—Summary of Objectives

Nutrition and Overweight

Goal: Promote health and reduce chronic disease associated with diet and weight.

Healthy People 2010 Objectives

Weight Status and Growth

19-1. Increase the proportion of adults who are at a healthy weight.

Target: 60 percent.

Baseline: 42 percent of adults aged 20 years and older were at a healthy weight (defined as a body mass index (BMI) equal to or greater than 18.5 and less than 25) in 1988-94 (age adjusted to the year 2000 standard population).

Target setting method: Better than the best.

Data source: National Health and Nutrition Examination Survey (NHANES), CDC, NCHS.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Age adjusted to the year 2000 standard population.

*Data for females and males are displayed to further characterize the issue.

HA household income below 130 percent of poverty threshold is used by the Food Stamp Program.

19-2. Reduce the proportion of adults who are obese.

Target: 15 percent.

Baseline: 23 percent of adults aged 20 years and older were identified as obese (defined as a BMI of 30 or more) in 1988-94 (age adjusted to the year 2000 standard population).

Target setting method: Better than the best.

Data source: National Health and Nutrition Examination Survey (NHANES), CDC, NCHS.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Age adjusted to the year 2000 standard population.

*Data for females and males are displayed to further characterize the issue.

HA household income below 130 percent of poverty threshold is used by the Food Stamp Program.

19-3. Reduce the proportion of children and adolescents who are overweight or obese.

Target and baseline:

*Defined as at or above the gender- and age-specific 95th percentile of BMI based on a preliminary analysis of data used to construct the year 2000 U.S. Growth Charts.

HPreliminary data.

Target setting method: Better than the best.

Data source: National Health and Nutrition Examination Survey (NHANES), CDC, NCHS.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: preliminary data.

*A household income below 130 percent of poverty threshold is used by the Food Stamp Program.

Maintenance of a healthy weight is a major goal in the effort to reduce the burden of illness and its consequent reduction in quality of life and life expectancy. The selection of a BMI cut-point to establish the upper limit of the healthy weight range is based on the relationship of overweight or obesity to risk factors for chronic disease or premature death. A BMI of less than 25 has been accepted by numerous groups as the upper limit of the healthy weight range, since chronic disease risk increases in most populations at or above this cut-point.^{14, 15, 29} The lower cut-point for the healthy weight range (BMI of 18.5) was selected to be consistent with national and international recommendations.^{14, 15} Problems associated with excessive thinness (BMI less than 18.5) include menstrual irregularity, infertility, and osteoporosis. There is some concern that the increased focus on overweight may result in more eating disorders, such as bulimia and anorexia nervosa. (See Focus Area 18. Mental Health and Mental Disorders.) However, no evidence currently exists that suggests the increased focus on overweight has resulted in additional cases of eating disorders.

Overweight and obesity are caused by many factors. These factors reflect the contributions of inherited, metabolic, behavioral, environmental, cultural, and socioeconomic components. As weight increases, so does the prevalence of health risks. Simple, health-oriented definitions of overweight and obesity should be based on the amount of excess body fat at which health risks to individuals begin to increase. No such definitions currently exist. Most current clinical studies assessing the health effects of overweight rely on a measurement of body weight adjusted for height. BMI is the choice for many researchers and health professionals. While the relation of BMI to body fat differs by age and gender, it provides valid comparisons across racial and ethnic groups.²⁹ However, BMI does not provide information concerning body fat distribution, which has been identified as an independent predictor of health risk.³⁰ Thus, until a better surrogate for body fat is developed, BMI will be used to screen for overweight and obese individuals.

Interpretations of data about overweight and obesity have differed because criteria for these terms have varied over time, from study to study, and from one part of the world to another. National and international organizations now support the use of a BMI of 30 or greater to identify obesity.^{14, 15} These BMI cut-points are only a guide to the identification and treatment of overweight and obese individuals and allow for the comparison across populations and over time. However, the health risks associated with overweight and obesity are part of a continuum and do not conform to rigid cut-points.

Overweight and obesity affect a large proportion of the U.S. population—55 percent of adults. Over two decades, the number of cases of obesity alone has increased more than 50 percent—from 14.5 percent of the adult population to 22.5 percent. Approximately 25 percent of U.S. adult females and 20 percent of U.S. adult males are obese.¹² Since weight management is difficult for most persons, the 2010 target of no more than 15 percent of adults aged 20 years and older having a BMI of 30 or more is ambitious. Nonetheless, the potential benefits from reduction in overweight and obesity are of considerable public health importance and deserve particular emphasis and attention. A concerted public effort will be needed to prevent further increases of overweight and obesity. Health care providers, health plans, and managed care organizations need to be alert to the development of overweight and obesity in their clients and should provide information concerning the associated risks. These groups need to provide guidance to help consumers address this health problem. To lose weight and keep it off, overweight persons will need long-term lifestyle changes in dietary and physical activity patterns that they can easily incorporate into their lives.

Patterns of healthful eating behavior need to begin in childhood and be maintained throughout adulthood. These patterns can be encouraged through nutrition education at schools and worksites that takes into account cultural and other factors influencing diet. Persons should be aware of the impact that away-from-home eating can have on weight management. In order to address physical activity needs, changes in the physical environment—such as access to walkways and bicycle paths—and the social environment—through social support and safe communities—will be needed to achieve long-term success.

There is much concern about the increasing prevalence of obesity in children and adolescents. Overweight and obesity acquired during childhood or adolescence may persist into adulthood and increase the risk for some chronic diseases later in life. Teenaged boys lose some fat accumulated before puberty during adolescence, but fat deposition continues in girls. Thus, without measures of sexual maturity, measures of body fat and body weight are difficult to interpret in preadolescents and adolescents. Therefore, the objective to reduce the prevalence of overweight and obesity among children and adolescents has a target set at no more than 5 percent and uses the gender- and age-specific 95th percentile of BMI from the year 2000 National Center for Health Statistics/Centers for Disease Control and Prevention (NCHS/CDC) growth charts. Interventions need to recognize that obese children also may experience psychological stress. The reduction of BMI in children and adolescents should be achieved by emphasizing physical activity and a properly balanced diet so that healthy growth is maintained. Additional research is needed to better define the prevalence and health consequences of overweight and obesity in children and adolescents and the implications of such findings for these persons as they become the next generation of adults.

19-4. Reduce growth retardation among low-income children under age 5 years.

Target: 5 percent.

Baseline: 8 percent of low-income children under age 5 years were growth retarded in 1997 (defined as height-for-age below the fifth percentile in the age-gender appropriate population using the 1977 NCHS/CDC growth charts;³¹ preliminary data; not age adjusted).

Target setting method: Better than the best.

Data source: Pediatric Nutrition Surveillance System, CDC, NCCDPHP.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Preliminary data; not age adjusted.

*Data for specific age groups under 5 years are displayed to further characterize the issue.

Retardation in linear growth in preschool children serves as an indicator of overall health and development and also may reflect the adequacy of a child’s diet. Full growth potential may not be reached because of less than optimal nutrition, infectious diseases, chronic diseases, or poor health care. Inadequate maternal weight gain during pregnancy and other prenatal factors that influence birth weight also affect the prevalance of growth retardation among infants and young children.

Growth retardation is not a problem for the majority of young children in the United States. By definition, approximately 5 percent of healthy children are expected to be below the fifth percentile of height for age due to normal biologic variation. If more than 5 percent of a population group is below the fifth percentile, this suggests that full growth potential is not being reached by some children in that group. Among some age and ethnic groups of low-income children under age 5 years in the United States, up to 15 percent are below the fifth percentile. While progress has been made in reducing the prevalence of growth retardation among low-income Hispanic and Asian or Pacific Islander children, it remains especially high for African American children in the first year of life.

Interventions to improve children’s linear growth potential include better nutrition; improvements in the prevention, diagnosis, and treatment of infectious and chronic diseases; and provision and use of adequate health services. Although the response of a population to interventions for growth retardation may not be as rapid as for iron deficiency or underweight, achievement of the objective by the year 2010 in all racial and ethnic, socioeconomic, and age subgroups should be possible. Special attention should be given to homeless children and those with special health care needs.

Food and Nutrient Consumption

19-5. Increase the proportion of persons aged 2 years and older who consume at least two daily servings of fruit.

Target: 75 percent.

Baseline: 28 percent of persons aged 2 years and older consumed at least two daily servings of fruit in 1994-96 (age adjusted to the year 2000 standard population).

Target setting method: Better than the best.

Data source: Continuing Survey of Food Intakes by Individuals (CSFII) (2-day average), USDA.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Age adjusted to the year 2000 standard population.

*A household income below 130 percent of poverty threshold is used by the Food Stamp Program.

19-6. Increase the proportion of persons aged 2 years and older who consume at least three daily servings of vegetables, with at least one-third being dark green or deep yellow vegetables.

Target: 50 percent.

Baseline: 3 percent of persons aged 2 years and older consumed at least three daily servings of vegetables, with at least one-third of these servings being dark green or deep yellow vegetables in 1994-96 (age adjusted to the year 2000 standard population).

Target setting method: Better than the best.

Data source: Continuing Survey of Food Intakes by Individuals (CSFII) (2-day average), USDA.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Aged adjusted to the year 2000 standard population.

*Data for number and type of daily servings are displayed to further characterize the issue.

HA household income below 130 percent of poverty threshold is used by the Food Stamp Program.

19-7. Increase the proportion of persons aged 2 years and older who consume at least six daily servings of grain products, with at least three being whole grains.

Target: 50 percent.

Baseline: 7 percent of persons aged 2 years and older consumed at least six daily servings of grain products, with at least three being whole grains in 1994-96 (age adjusted to the year 2000 standard population).

Target setting method: Better than the best.

Data source: Continuing Survey of Food Intakes by Individuals (CSFII) (2-day average), USDA.

DNA=Data have not been analyzed. DNC=Data are not collected. DSU=Data are statistically unreliable.

Note: Age adjusted to the year 2000 standard population.

*Data for number and type of daily servings are displayed to further characterize the issue.

HA household income below 130 percent of poverty threshold is used by the Food Stamp Program.

The 1995 Dietary Guidelines for Americans recommend that Americans choose a diet with plenty of grain products, vegetables, and fruits, which is also low in fat, saturated fat, and cholesterol and moderate in salt, sodium, and sugars.⁶ Many Americans of all ages eat fewer than the recommended number of servings of grain products, vegetables, and fruits.²⁸ Vegetables (including legumes, such as beans and peas), fruits, and grains are good sources of complex carbohydrates (starch and dietary fiber), vitamins and minerals, and other substances that are important for good health. Some evidence from clinical studies suggests that water-soluble fibers from foods such as oat bran, beans, and certain fruits are associated with lower blood glucose and blood lipid levels.³² Dietary patterns with higher intakes of vegetables (including legumes), fruits, and grains are associated with a variety of health benefits, including a decreased risk for some types of cancer.^{32, 33, 34, 35, 36, 37}</