Society of Behavioral Medicine

What is Obesity?

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.

For children and teens, BMI ranges above a normal weight have different labels (at risk of overweight and overweight). Additionally, BMI ranges for children and teens are defined so that they take into account normal differences in body fat between boys and girls and differences in body fat at various ages. 1

  • During the past 20 years, obesity among adults has risen significantly in the United States. Thirty percent of U.S. adults 20 years of age and older-over 60 million people-are obese. 2
  • Nearly two-thirds of U.S. adults are overweight (BMI > 25, which includes those who are obese). 3
    • All adults (20+ years old): 129.6 million (64.5 percent)
    • Women (20+ years old): 64.5 million (61.9 percent)
    • Men (20+ years old): 65.1 million (67.2 percent)
  • Nearly one-third of U.S. adults are obese (BMI > 30). 1
    • All adults (20+ years old): 61.3 million (30.5 percent)
    • Women (20+ years old): 34.7 million (33.4 percent)
    • Men (20+ years old): 26.6 million (27.5 percent)
  • Less than half of U.S. adults have a healthy weight (BMI > 18.5 to < 25). 4
    • All adults (20-74 years old): 67.3 million (33.5 percent)
    • Women (20-74 years old): 36.7 million (35.3 percent)
    • Men (20-74 years old): 30.6 million (31.8 percent)
  • From 1960 to 2000, the prevalence of overweight (BMI > 25 to < 30) increased from 31.5 to 33.6 percent in U.S. adults aged 20 to 74. 2
  • The prevalence of obesity (BMI > 30) during this same time period more than doubled from 13.3 to 30.9 percent, with most of this rise occurring in the past 20 years. 2
  • From 1988 to 2000, the prevalence of extreme obesity (BMI > 40) increased from 2.9 to 4.7 percent, up from 0.8 percent in 1960.3,8 In 1991, four states had obesity rates of 15 percent or higher, and none had obesity rates above 16 percent. 2
  • By 2000, every state except Colorado had obesity rates of 15 percent or more, and 22 states had obesity rates of 20 percent or more. 5
  • The prevalence of overweight and obesity generally increases with advancing age, then starts to decline among people over 60. 3
  • The age-adjusted prevalence of combined overweight and obesity (BMI > 25) in racial/ethnic minorities-especially minority women-is generally higher than in whites in the United States. 1
    • Non-Hispanic Black women: 77.3%
    • Mexican American women: 71.9%
    • Non-Hispanic White women: 57.3%
    • Non-Hispanic Black men: 60.7%
    • Mexican American men: 74.7%
    • Non-Hispanic White men: 67.4%

(Statistics are for populations 20+ years old)

  • Adult men and women are roughly an inch taller than they were in 1960, but are nearly 25 pounds heavier on average as well, according to a new report from the Centers for Disease Control and Prevention. 1
    • Men between the ages of 40 and 49 were nearly 27 pounds heavier on average in 2002 compared to 1960.
    • Men between the ages of 50 and 59 were nearly 28 pounds heavier on average in 2002 compared to 1960.
    • Men between the ages of 60 and 74 were almost 33 pounds heavier on average in 2002 compared to 1960.
    For women, the near opposite trend occurred:
    • Women aged 20-29 were nearly 29 pounds heavier on average in 2002 compared to 1960.
    • Women aged 40-49 were about 25½ pounds heavier on average in 2002 compared to 1960.
    • Women aged 60-74 were about 17½ pounds heavier on average in 2002 compared to 1960.
  • Approximately 15.3 percent of children (ages 6-11) and 15.5 percent of adolescents (ages 12-19) were overweight in 2000. An additional 15 percent of children and 14.9 percent of adolescents were at risk for overweight (BMI for age between the 85th and 95th percentile). 3
  • Among people diagnosed with type 2 (noninsulin-dependent) diabetes, 67 percent have a BMI > 27 and 46 percent have a BMI > 30. 6
  • About 17 million people in the U.S. have type 2 diabetes, accounting for more than 90 percent of diabetes cases. 7
  • An additional 20 million have impaired glucose tolerance, sometimes called pre-diabetes, which is a strong risk factor for developing diabetes later in life. 5
  • An estimated 70 percent of diabetes risk in the U.S. can be attributed to excess weight. 8
  • Total costs of overweight an obesity:
    • Total cost: $117 billion
    • Direct cost: $61 billion
    • Indirect cost: $56 billion (comparable to the economic costs of cigarette smoking)
  • The cost of lost productivity related to obesity (BMI > 30) among Americans ages 17-64 is $3.9 billion. This value considers the following annual numbers (for 1994): 9
    • Workdays lost related to obesity: 39.3 million
    • Physician office visits related to obesity: 62.7 million
    • Restricted activity days related to obesity: 239.0 million
    • Bed-days related to obesity: 89.5 million

1 Centers for Disease Control and Prevention Web site: www.cdc.gov
2 The National Center for Health Statistics
3 Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. Journal of the American Medical Association. 2002;288:1723-1727.
4 Pastor PN, Makuc DM, Reuben C, Xia H. Chartbook on Trends in the Health of Americans. Health, United States, 2002. Hyattsville, MD: National Center for Health Statistics. 2002.
5 Ogden CL, Flegal KM, Carroll MD, Johnson CL. Prevalence and trends in overweight among US children and adolescents, 1999-2000. Journal of the American Medical Association. 2002;288:1728-1732.
6 http://win.niddk.nih.gov/statistics/index.htm#preval Personal communication from Maureen I. Harris, NIDDK/NIH, to Susan Z. Yanovski, NIDDK/NIH, 1999.
7 Centers for Disease Control and Prevention. National diabetes fact sheet: General information and national estimates on diabetes in the United States, 2000. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2002.
8 National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes Prevention Program Meeting Summary. August 2001. Diabetes Mellitus Interagency Coordinating Committee.
9 http://win.niddk.nih.gov/statistics/index.htm#preval
http://www.sbm.org/media/facts/obesity.cfm