Problem with non-normalized fat free and body fat masses: A tall person with protein energy malnutrition may have values comparable to a shorter person who is well-nourished.
Fat free or lean body mass is estimated or measured using a method such as bioimpedance, body density, or skinfold measures.
body fat mass in kilograms =
= (total body mass in kilograms) – (fat free mass in kilograms)
fat free mass index (FFMI) =
= (fat free body mass in kilograms) / ((body height in meters)^2)
body fat mass index (BFMI) =
= (body fat mass in kilograms) / ((body height in meters)^2)
Because (body mass) = (fat free mass) + (body fat mass)
body mass index (BMI) =
= FFMI + BFMI
Interpretation:
• A FFMI or BFMI below the 5th percentile for a reference population was associated with protein-energy malnutrition.
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Minnesota Study of Keys et al (1950)
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50th percentile
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5th percentile
|
|
FFMI
|
20 kg per square meter
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17 kg per square meter
|
|
BFMI
|
4.4 kg per square meter
|
2.45 kg per square meter
|
from Figures 2 and 3, page 955, VanItallie (1990)
It might be interesting to see if the ratio of the (body fat mass) / (fat free body mass) has any use in obesity research.
