Whole body plethysmography (Bod Pod)11
|
Body volume and weight to determine density |
Density of fat and lean mass is constant with age, BMI, and ethnicity |
Two compartments, fat and fat free mass |
DXA22
|
Absorption of two different energy X‐rays |
X‐ray absorption is directly related to bone, fat, and lean mass |
Direct measure of bone density, fat, and lean mass does not measure muscle mass |
Bioelectrical impedance/bioelectrical spectroscopy16, 17
|
Resistance and reactance to a single or multiple frequency (BIS) electrical current |
Resistance and reactance values are associated with body water content |
Value is strongly associated with total body water, including intracellular and extracellular; does not measure muscle mass |
24‐h urine creatinine34
|
Excretion of creatinine in a 24‐h urine collection |
No urine is lost during collection period; no dietary creatinine; creatinine excretion reflects total body creatine pool; creatine pool size is a measurement of muscle mass |
Total body creatine pool size, skeletal muscle mass |
D3‐Creatine dilution37
|
Enrichment of D3‐creatinine in single urine sample |
Urine D3‐creatinine represents muscle D3‐creatine enrichment; creatine pool size is a measurement of muscle mass |
Total body creatine pool size, skeletal muscle mass |