Method of in-vivo measurement of fat content of a body and apparatus therefor

A method for determining the total body fat of a living human organism using an FT-NIR analytical technique, said method comprising the steps of:

• (a) directing a beam of light in the near-infrared frequency range from a light source to a subcutaneous layer test site of the body of the living human organism, wherein said beam of light is swept over a pre-determined frequency band of light in the near-infrared frequency range, and wherein said test site is defined by a portion of the body of the living human organism having an epidermis layer, a dermis layer, and said subcutaneous layer, and is subtended by bone or cartilage;
• (b) detecting light reflected from said test site of the body of the living human organism by a detector;
• (c) recording the intensity of energy absorptions in said reflected light in the form of an interferogram as a function of time;
• (d) performing Fourier Transform calculations to the data in said interferogram so as to convert said data in said interferogram to a spectrum;
• (e) extracting from said spectrum information concerning specific frequencies and intensity of energy absorptions at said specific frequencies so as to calculate a response value;
• and
• (f) determining the total body fat content by incorporating said response value from step (e) into an empirical formula wherein said empirical formula is:
• Female:
• TBF=64.719 N*W0.51456*H0.42246/(−0.001 A+0.989)W
• Male:
• TBF=64.719 N*W0.51456*H0.42246/(−0.003 A+0.9971)W
• where TBF is the total body fat in percent, N is said response value, W is the weight in kilograms, H is the height in centimeters, and A is the age in years of the living human organism.