On 3/4/2011 6:38 PM, Dave Smith wrote:
Apparently there's a different way to analyze your fat mass.
Bioelectrical Impedance analysis.
"Height-Weight Tables were originally developed by insurance companies
to establish recommended weight ranges for men and women. The
"desirable" weights were those associated with the lowest mortality
among large population studies of insured people. Unfortunately, these
studies do not accurately represent a cross-section of the entire
American population."
"Bioelectrical Impedance
Body impedance is measured when a small, safe electrical signal is
passed through the body, carried by water and fluids. Impedance is
greatest in fat tissue, which contains only 10-20% water, while fat-free
mass, which contains 70-75% water, allows the signal to pass much more
easily. By using the impedance measurements along with a person's height
and weight, and body type (gender, age, fitness level), it is possible
to calculate the percentage of body fat, fat-free mass, hydration level,
and other body composition values. Conventional BIA normally uses
underwater weighing as its method of reference.
Using BIA to estimate person's body fat assumes that the body is within
normal hydration ranges. When a person is dehydrated, the amount of fat
tissue can be overestimated. Factors that can affect hydration include
not drinking enough fluids, drinking too much caffeine or alcohol,
exercising or eating just before measuring, certain prescription drugs
or diuretics, illness, or a woman's menstrual cycle. Measuring under
consistent conditions (proper hydration and same time of day) will yield
best results with this method."
More:
http://new-fitness.com/body_fat_measuring.html