Recent
results of the National Health and Nutrition Examination Survey
(NHANES) 1999 indicate that an estimated 61 percent of U.S.
adults are either overweight or obese, defined as having a
body
mass index (BMI) of 25 or more.
- Among
U.S. adults aged 20-74 years, the prevalence of overweight
(defined as BMI 25.029.9) has increased an estimated 2
percent since 1980, increasing from 33 percent to the 35
percent of the population in 1999 (based on NHANES II and
NHANES 1999 data).
- In
the same population, obesity (defined as BMI greater
than or equal to 30.0) has nearly doubled from approximately
15 percent in 1980 to an estimated 27 percent in 1999.
Overweight
Overweight
refers to increased body weight in relation to height, when
compared to some standard of acceptable or desirable weight
(NRC p.114; Stunkard p.14). NOTE: Overweight may or
may not be due to increases in body fat. It may also be due
to an increase in lean muscle. For example, professional athletes
may be very lean and muscular, with very little body fat,
yet they may weigh more than others of the same height. While
they may qualify as "overweight" due to their large
muscle mass, they are not necessarily "over fat,"
regardless of BMI.
Desirable
weight standards are derived in a number of ways:
- By
using a mathematical formula known as Body Mass Index (BMI),
which represents weight levels associated with the lowest
overall risk to health. Desirable BMI levels may vary with
age.
- By
using actual heights and weights measured and collected
on people who are representative of the U.S. population
by the National Center for Health Statistics. Other desirable
weight tables have been created by the Metropolitan Life
Insurance Company, based on their client populations.
These
sources are consistent with the U.S. Dietary Guidelines and
with the National Heart, Lung, and Blood Institute's Clinical
Guidelines on the Identification, Evaluation, and Treatment
of Overweight and Obesity in Adults.
Common
typos:
overewight, ovewreight, ovreweight, oevrweight, voerweight,
overweigh, verweight, overweigth, overweihgt, overwegiht
source:
http://www.cdc.gov/nccdphp/dnpa/obesity/defining.htm
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