Obesity Trends among U.S. Adults

Map

Date: 2004

Source: Centers for Disease Control and Prevention (CDC). 〈http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps〉 (accessed August 20, 2005). The map shows trends in obesity in the United States during 1991–2004.

About the Author: The Centers for Disease Control and Prevention is a federal government agency that provides health and safety information for U.S. citizens and international health professionals. It reports accurate and timely information regarding health issues, and develops and applies disease prevention and control measures. The CDC is also involved in health promotion and education.

INTRODUCTION

The surveillance of behavioral factors that increase the risk of chronic disease is a key epidemiological (the study and documentation of disease patterns) responsibility of the Centers for Disease Control and Prevention (CDC). Assessing trends in the prevalence of certain behaviors such as smoking and excess calorie consumption is an important surveillance activity for calculating and predicting the current and future burden of chronic illness in the United States.

In 1984, the CDC established the Behavioral Risk Factor Surveillance System (BRFSS) to help in the accumulation and statistical analysis of health and safety data using a telephone survey. The surveillance survey gathers reports on fifty-four different behavioral risk areas. The BRFSS is used by the states to generate policies and initiate disease prevention programs, often with the support of the CDC.

One of the major programs funded by the CDC is the National Nutrition and Physical Activity Program to Prevent Obesity and Other Chronic Diseases. The program provides assistance with training of health professionals, and community initiatives to encourage healthier eating and physical activity. The objective of this program is to assist nutritionists in counseling patients to establish healthy eating habits by reducing calorie intake, increasing the consumption of fruits and vegetables, establishing a balanced diet, and maintaining a healthy body weight.

PRIMARY SOURCE

OBESITY TRENDS AMONG U.S. ADULTS

See primary source image.

SIGNIFICANCE

During the past twenty years, there has been a dramatic increase in obesity in the United States. In 1991, four states had obesity prevalence rates of 15 to 19 percent and no states had rates at or above 20 percent. In 2004, seven states had obesity prevalence rates of 15 to 19 percent; thirty-three states had rates of 20 to 24 percent; and nine states had rates greater than 25 percent.

The rapid increase in obesity rates between 1985 and 2004 has been blamed on a number of factors. The major contributors to these have been identified by the CDC and population health researchers as high-fat, high-calorie diets; reduced physical activity, due mainly to increased time spent watching television, working on computers, or playing video games; and an increased dependence on automobiles for transportation, even for short distances. According to the CDC map, the most pronounced increase in obesity prevalence has been in the Southern and Midwestern United States. This could involve dietary patterns as well as racial composition and other lifestyle patterns. The prevalence of obesity is higher in the African American and Latino minority population.

The diets of people living in western nations, especially Americans, are characterized by an increased consumption of convenience and "fast" foods with a higher fat or sugar content than more traditional foods. These changes in eating habits are primarily attributed to longer working hours and to less time spent preparing meals at home. Along with the changes in type of food consumed, portion sizes have increased dramatically over the past twenty years, particularly in fast food outlets. This combination of factors has resulted in significantly increased calorie intake.

According to the CDC, based on body mass index (BMI) statistics, approximately 65 percent of Americans were classified as overweight and 30 percent of adults over twenty years of age were obese in 2004—about 60 million people. While BMI has shortcomings as a measure of obesity (e.g., the confounding of body fat and muscle mass), trends in BMI are generally indicative of obesity trends. Although the percentage of overweight people has not increased significantly over the past ten years, the level of obesity has nearly doubled, from 11.6 percent in 1995 to 22.1 percent in 2005. This increase has occurred in all age groups, although the highest percentage is among adults between fifty and sixty-four years of age. Disturbingly, 16 percent of children between six and nineteen years of age are overweight.

A significant consequence of the obesity epidemic is an increase in the level of chronic or life-threatening diseases, such as type 2 diabetes, hypertension, stroke, osteoarthritis, some cancers (endometrial, breast, and colon), high cholesterol levels, and respiratory problems. The percentage of people at risk for such conditions nationwide in the United States increased from 29.7 percent in 1995 to 58.9 percent in 2002. This increase in chronic or life-threatening diseases has led to a dramatic increase in direct and indirect medical costs. In 2000, these costs were estimated to be more than 117 billion dollars.

Because obesity results from reduced physical activity as well as increased calorie consumption, CDC campaigns also target physical exercise. According to CDC data from 2000, over 26 percent of Americans, including children and teenagers, are not getting enough exercise. The decrease in physical activity among people in younger age brackets, often ascribed to more time spent watching television or using computers, is particularly alarming because it multiplies the long-term population risk of the chronic diseases mentioned above.

The rise of obesity among children is of particular concern. According to the American Obesity Association (AOA), "Today's youth are considered the most inactive generation in history caused in part by reductions in school physical education programs and unavailable or unsafe community recreational facilities." The AOA calls the trend toward obesity in children "the major health care challenge for the twenty-first century." The AOA is an advocacy group that sponsors research into the treatment and cure of obesity and pushes for the coverage of obesity treatments under health insurance.

The extent of the emerging health crisis associated with childhood obesity is exemplified by several trends. About 30 percent of children aged six to eleven are considered overweight and 15 percent are classified by the CDC as obese. The figures for adolescents (ages twelve to nineteen) are similar. Excess weight in childhood and adolescence has been found to predict overweight status in adults, particularly when there is a familial pattern of obesity. In one study reported by the AOA, overweight children aged ten to fourteen with at least one overweight or obese parent were reported to have a 79 percent likelihood of becoming overweight or obese adults.

Numerous studies in the major chronic disease areas have demonstrated that excess weight during childhood and particularly adolescence is related to elevated morbidity and mortality in adulthood. Children and adolescents with moderate to severe asthma have a significantly higher prevalence of overweight status than a matched control group. The prevalence of type 2 diabetes has quadrupled in children and doubled in adolescents from 1975 to 2000. This increase is largely accounted for by a parallel increase in the prevalence of obesity in these age groups. Obese children have been found to have a prevalence of persistently elevated blood pressure that is nine times higher than the prevalence among non-obese children.

Growing evidence in obesity research indicates that obesity, and childhood obesity in particular, is a medical, social and economic time bomb for Western society. In recent years, the epidemic of obesity with a concomitant increase in the prevalence of diabetes and cardiovascular disease is spreading to emerging industrializing nations as well, notably China. All indications point to obesity becoming a condition that is as widespread and as lethal and expensive a risk factor for disease and death as smoking was in the twentieth century.

FURTHER RESOURCES

Periodicals

Calle, E. E., et al. "Body Mass Index and Mortality in a Prospective Cohort of U.S. Adults." New England Journal of Medicine 341 (October 7, 1999): 1097-1105.

Mokdad, A. H., et al. "The Continuing Epidemics of Obesity and Diabetes in the United States." Journal of the American Medical Association 286 (September 12, 2001):1195-1200.

――――――. "Prevalence of Obesity, Diabetes, and Obesity-related Health Risk Factors, 2001." Journal of the American Medical Association 289 (January 1, 2003): 76-79.

Web sites

American Obesity Association Web site. "AOA Fact Sheet." 〈www.obesity.org〉 (accessed February 1, 2006).

The Centers for Disease Control and Prevention. "Overweight and Obesity: Defining Overweight and Obesity." 〈http://www.cdc.gov/nccdphp/dnpa/obesity/defining.htm〉 (accessed May 10, 2005).

National Institute of Diabetes and Digestive and Kidney Diseases. "Understanding Adult Obesity." 〈http://win.niddk.nih.gov/publications/understanding.htm〉 (accessed May 10, 2005).

U.S. Department of Health and Human Services. "The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity." 〈http://www.surgeongeneral.gov/topics/obesity/calltoaction/CalltoAction.pdf〉 (accessed May 10, 2005).