CDC Efforts to Reduce or Prevent Obesity

Overweight and Obesity Overview

The prevalence of overweight and obesity has increased substantially over the past several decades. The latest National Health and Nutrition Examination Survey (NHANES) data indicate 65 percent of U.S. adults aged 20 years and older are overweight with a body mass index (BMI) of 25 or higher, or obese with a BMI of 30 or higher. In addition, 16 percent of children and adolescents ages 6-19 in the United States are overweight.

Body mass index (BMI) is a measure of weight adjusted for height. Although it does not differentiate between body fat and muscle mass, BMI is a useful tool for indicating whether a person is underweight, at a healthy weight, overweight or obese.

According to The Surgeon General’s Call to Action to Prevent and Decrease Overweight and Obesity, the medical and related costs of obesity in the United States in 2000 was more than $117 billion. Overweight and obesity have been associated with a number of conditions. Among these are heart disease, stroke, diabetes, cancer (such as colon cancer, endometrial cancer, and postmenopausal breast cancer) and osteoarthritis.

Two studies in the April 20, 2005 issue of Journal of the American Medical Association (JAMA) provide more information on issues related to obesity and mortality.

“Excess Deaths Associated with

Underweight, Overweight and Obesity”

Using data collected from the most recent NHANES, Katherine Flegal, Ph.D., CDC’s National Center for Health Statistics, and her co-authors from CDC and the National Cancer Institute, part of the National Institutes of Health, found that both obesity and being underweight are associated with excess deaths when compared with the normal weight population.

The study found:

There were 112,000 more deaths than expected in 2000 among obese individuals (BMI of 30 or higher).

  Underweight individuals (BMI of less than 18.5) had a higher risk of death with nearly 34,000 more deaths than expected.

  Most of the excess deaths among the underweight occurred in people age 70 or older. Among the obese, the increased risk of death was most pronounced among people younger than 70.

  Being overweight (BMI of 25-29.9) was not associated with excess mortality. The study found that 87,000 fewer deaths than expected were associated with being overweight.

“Secular Trends in Cardiovascular Disease Risk Factors

According to Body Mass Index in US Adults”

Edward Gregg, Ph.D., of CDC’s diabetes program and his CDC co-authors, analyzed NHANES data and found large decreases in many of the cardiovascular disease risk factors known to be associated with early deaths in all U.S. adults ages 20-74, regardless of their BMI. The exception was diabetes. The prevalence of total (diagnosed and undiagnosed) diabetes increased by 55 percent over the past 40 years, likely the result of the dramatic increase in obesity during this time period.

Other key findings:

Prevalence of elevated cholesterol and blood pressure dropped by almost half in all U.S. adults ages 20-74, while smoking prevalence dropped by about a third.

Reductions in the prevalence of high cholesterol levels were most substantial among obese people compared to lean individuals.

Reductions in blood pressure and smoking prevalence were similar among lean and obese persons.

CDC Efforts to Reduce or Prevent Obesity

Because the current generation of children, adolescents and young adults is the most overweight in our nation’s history, reducing obesity is one of CDC’s top health priorities. CDC is undertaking an agency-wide effort to conduct research activities and programs to improve our understanding of all the ways that obesity can affect health, as well as identify strategies to prevent obesity-related health problems. CDC’s efforts include surveillance, prevention research, and state, community and school-based programs in nutrition and physical activity.