(January 2003) In September 2002, the National Center for Health Statistics announced that U.S. life expectancy in 2000 had hit an all-time high: nearly 77 years. The following month, the U.S. Centers for Disease Control and Prevention reported that obesity had also reached an all-time high, which threatens to diminish the gains in life expectancy.

In 2000, 31 percent of U.S. adults were obese — a 35 percent increase since 1994.1 Fifteen percent of children ages 6 to 11 were overweight — triple the level in 1974 (see Figure 1). The obesity epidemic is raging in other countries as well (see Figure 2).

Figure 1

Percent of American Children Who Are Overweight, Selected Years


Note: Children with a body mass index (BMI) at or above the 95th percentile of the sex-specific BMI growth charts are considered overweight.
Source: National Center for Health Statistics (NCHS), NCHS Health E-Stats.

Figure 2

Percent of Adults Who Are Obese, Selected Countries, 1998-2000


Note: Obesity is defined as a body mass index (BMI) of 30 or higher.
Source: Organization for Economic Cooperation and Development (OECD), OECD Health 2002 (www.oecd.org/, accessed Oct. 18, 2002).

What is the connection between life expectancy and obesity? Each year, an estimated 300,000 U.S. adults die of obesity-related causes. Obesity has been linked to increased rates of heart disease, cancer, and diabetes, which rank as the first, second, and sixth causes of death in the United States, respectively. Chronically overweight children face a number of long-term health problems and a heightened risk of developing blindness, kidney problems, and heart disease by the time they turn 30.2 Black Americans, who are at greater risk of obesity than whites, also face a higher risk of death from diabetes and other diet- and weight-related illnesses.

George L. Blackburn, chairman of nutrition medicine at Harvard Medical School, recently told the Washington Post, “We are totally losing the battle to prevent and treat obesity,” and unless efforts are redoubled for early identification and early prevention of excessive weight gain, “we are going to have the first generation of children who are not going to live as long as their parents.”3

A recent report by the U.S. Institute of Medicine (IOM) recommends policy changes that could temper this negative trend by promoting healthier lifestyles. The most controversial recommendation is that individuals should engage in one hour of physical activity a day to balance their energy (calorie) intake and expenditure. That advice roughly doubles previous recommendations from the U.S. Surgeon General.

What policy changes may emerge when agencies such as the National Institutes of Health implement the report’s recommendations? Benjamin Caballero, director of the Center for Human Nutrition, Johns Hopkins University, anticipates changes in food labeling practices, school lunch requirements, and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

George A. Brooks, University of California-Berkeley professor and IOM panel member, spoke of the need for a national strategy and of the importance of physical education in schools. “We need to think about the curriculum in the schools so that kids will get the skills to be active and learn how to be active and like it.”4


  1. National Center for Health Statistics, “Obesity Still on the Rise, New Data Show,” HHS News (Oct. 8, 2002), accessed online at www.cdc.gov/nchs/releases/02news/obesityonrise.htm, on Oct. 18, 2002.
  2. U.S. Institute of Medicine, “Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids (Macronutrients),” accessed online at www.nap.edu/books/0309085373/html/, on Oct. 28, 2002.
  3. Sally Squires, “Study Finds That in U.S., 1 in 3 Are Obese,” Washington Post, Oct. 9, 2002.
  4. Personal communication, Sept. 24, 2002.

Allison Tarmann is an editor at the Population Reference Bureau. This article is excerpted from PRB’s Population Bulletin “What Drives U.S. Population Growth?” (PDF: 559KB).