This paper presents and compare the scopes of the body component measurement methods and techniques currently in use. Next to the best known and widespread Adolphe Quetelet's Body Mass Index, ‘New Body Mass Index’ created by Prof. Trfethen. Moreover, it presents and compares the bioelectrical impedance analysis and the Electrical Impedance Myographs methods, too. This article aims to go through one by one the body component measurement methods, and to compare the most important feature of them, for a better understanding of their usability.