ABSTRACT
There has been considerable controversy over the years as to what is desirable weight gain during pregnancy, and guidelines have varied considerably over time. In its 1990 report, the Institute of Medicine (IOM) recommended that lean and underweight women should gain more weight during pregnancy than normal-weight women, who, in turn, were recommended to gain more weight than overweight women. Information regarding composition of the human body is required to understand its biology and function, relevant in relation to human health, and fundamental when assessing nutritional requirements. Pregnancy affects the female body in several ways, which has important consequences when methodology commonly used in human body composition research is applied to women during reproduction. The human body is composed of about 50 elements, but oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus account for >98" of body weight. The major components of the molecular level are water, fat or lipid, protein, mineral, and glycogen.
