Fat & Fat Free Mass

1. Fat & Fat Free Mass Should We Measure in MESA II?

2. Scientific Rationale • The effects of obesity are of major medical importance. • Currently our only measure of obesity is BMI. • BMI doesn’t fully account for differences in body composition that are unrelated to fat mass. • It may overestimate body fat in athletes and others who have a muscular build. • It may underestimate body fat in older persons and others who have lost muscle mass. • BMI is highly correlated to weight (r=0.8315).

3. Example of two individuals classified as obese based on BMI Ladamlian Tomlinson, running back for San Diego Chargers football team has a BMI of 33.6 , based on a height = 5’ 8’’ and weight = 221 lbs. A man with similar BMI

4. Use of Biolectrical Impedance (BIA) to Measure Fat and Fat Free Mass • BIA has been well validated. • Reference results available from NHANES III for whites, non-Hispanic blacks, and Hispanics (Body composition estimates from NHANES III bioelectrical impedance data bioelectrical impedance data. International Journal of Obesity (2002) 26, 1596 – 1611. • Total body water is also measured.

5. Practical Aspects • Choice of device • Tanita • Valhalla • Impedimed • Tanita and Valhalla devices include a scale and take only a minute or two more than just weighing the person. • The Impedimed device requires attaching two electrodes.

6. Recommendation • Valhalla device offers multiple advantages • Customized Report Available • No Disrobing - Keep Those Shoes On • Better than 0.5% repeatability • Correlates with Hydrostatic Weighing to within >99% • Accurate for athletes, bodybuilders, elderly and the obese • Device used by NHANES • Cost - $2,895 per unit • Fund from main study budget

7. Valhalla BIA Device

8. Valhalla Report