Over two-thirds of American adults are overweight or obese
(National Health and Nutrition Examination Survey, 2004), with
many estimates even higher (ACSM 2010). People must be more than
20 percent heavier than the recommended bodyweight for their
height to be considered obese, yet bodyweight based on height
chart assessments alone does not identify how much extra fat a
person is carrying. Another method that does not identify body
fat but rather uses bodyweight relative to height (kg/m2) is the
body mass index (BMI). The National Institutes of Health (2007)
use BMI values between 25 and 29.9 and those greater than 30 for
classifying people who are overweight and obese, respectively.
When skinfold measurements, or the more precise method of
underwater weighing, are used to determine body-fat percentage,
values that exceed the normal range by at least 5 percent are
considered obese. In older populations, ACSM (2010) has
suggested that satisfactory body-fat values for men and women
age 50 to 59 are between 10 a