Fourier transform near infrared spectroscopy: a newly developed, non-invasive method to measure body fat : non-invasive body fat content measurement using FT-NIR.

An FT-NIR technique is reported to provide a fast, accurate and low cost method of determining in-vivo human body fat content. The body fat content of 353 healthy subjects (154 males and 199 females) of various height, weight, and age were measured by FT-NIR and compared to 420 subjects investigated by magnetic resonance imaging (MRI). The procedure involved scanning each subject's upper ear that provided a necessary reflectance surface and proved representative of the subject's subcutaneous fat content. The average FT-NIR spectrum was compared to a reference mixture with known and similar fat content and composition to that of humans. The FT-NIR response was incorporated into an empirical equation using the ratio of subcutaneous to total body fat from MRI data, taking into account the subject's gender, height, weight and age. The results on the two data sets were similar and demonstrated that the FT-NIR technique can be used to obtain a measure of the body fat content of individuals, similar to that using MRI. In addition, the FT-NIR was used to more accurately monitor the fat content of sleep apnea patients.