Obesity is an Epidemic

The prevalence of obesity (BMI≥30) continues to be a health concern for adults, children and adolescents in the United States. Data from the most recent NHANES survey¹ shows that among adult men the prevalence of obesity was 31.1% in 2003—2004, and 33.3% in 2005—2006, a small but not statistically significant change. Among adult women, the prevalence of obesity in 2003—2004 was 33.2%, and in 2005—2006 was 35.3%, again a small but not significant change.

Another recent NHANES survey² found that obesity prevalence among children and adolescents showed no significant changes between 2003—2004 and 2005—2006. Based on the study, in the combined years of 2003—2006, 16.3% of children and adolescents aged 2–19 years were obese, at or above the 95th percentile of the 2000 BMI-for-age growth charts.

This rate of obesity raises concern because of its implications for the health of Americans. Obesity increases the risk of many diseases and health conditions. These include–

• Coronary heart disease
• Type 2 diabetes
• Cancers (endometrial, breast, and colon)
• Hypertension (high blood pressure)
• Dyslipidemia (for example, high total cholesterol or high levels of triglycerides)
• Stroke
• Liver and Gallbladder disease
• Sleep apnea and respiratory problems
• Osteoarthritis (a degeneration of cartilage and its underlying bone within a joint)
• Gynecological problems (abnormal menses, infertility)

Two of the Healthy People 2010 national health objectives³ are (1) to reduce the prevalence of overweight and obesity among adults to less than 15% and (2) to reduce the prevalence of obesity among children and adolescents to less than 5%. This site provides a variety of information designed to help people understand the severity of obesity, the efforts being made to address it, and how to maintain a healthy weight.

Definitions for Adults

For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the “body mass index” (BMI). BMI is used because, for most people, it correlates with their amount of body fat.

• An adult who has a BMI between 25 and 29.9 is considered overweight.
• An adult who has a BMI of 30 or higher is considered obese.

See the following table for an example.

It is important to remember that although BMI correlates with the amount of body fat, BMI does not directly measure body fat. As a result, some people, such as athletes, may have a BMI that identifies them as overweight even though they do not have excess body fat. For more information about BMI, visit Body Mass Index.

Other methods of estimating body fat and body fat distribution include measurements of skinfold thickness and waist circumference, calculation of waist-to-hip circumference ratios, and techniques such as ultrasound, computed tomography, and magnetic resonance imaging (MRI).

Selected Resources

Obesity: Successes and Opportunities for Population-Level Prevention and Control (PDF-2.3Mb)
Three innovative obesity prevention and control initiatives are focusing on policy and environmental change and making an impact. Learn more about the exciting work being accomplished through Michigan's Building Healthy Communities Program, Texas' Farm to Work Program; and the California Convergence Partnership.

Healthy Weight – It's not a diet, it's a lifestyle
Whether you want to lose weight or maintain a healthy weight, it’s important to understand the connection between the energy your body takes in (through the foods you eat and the beverages you drink) and the energy your body uses (through the activities you do).

At A Glance 2009 — Obesity, Halting the Epidemic by Making Health Easier

Weight Management Research to Practice Series
The Weight Management Research to Practice Series is a series designed to summarize the science on weight management topics for health professionals. An overview of the science will be compiled into a summary document appropriate for public health professionals, including implications for practice. In addition, each installment in the series will be accompanied by a tool geared toward a lay audience, which can be used by health professionals in practice.

References

¹Ogden CL, Carroll MD, McDowell MA, Flegal KM. Obesity among adults in the United States – no change since 2003—2004. NCHS data brief no 1. Hyattsville, MD: National Center for Health Statistics, 2007.

²Ogden CL, Carroll MD, Flegal KM. High Body Mass Index for Age Among US Children and Adolescents, 2003—2006. JAMA. 2008;299(20):2401—2405.

³U.S. Department of Health and Human Services. Healthy People 2010. 2nd ed. With Understanding and Improving Health and Objectives for Improving Health. 2 vols. Washington, DC: U.S. Government Printing Office, November 2000.