The human body is not of constant composition and is an assembly of different organs of differing composition.
The composition of the body can be evaluated at numerous levels of biological complexity, from basic elements (carbon, oxygen and hydrogen), molecules (water lipids, proteins) to whole tissue compartments (fats, muscle and bone) of the human body. If the human body is analyzed at different stages of life the composition differs.
The first level of body composition consists of 11 elements that comprise more than 99.5% of body weight. The primary elements are oxygen, hydrogen, carbon, nitrogen, and calcium.
The second level of body composition average human body contains about 20 % of fat, 15% protein, much smaller amounts of carbohydrate (perhaps I %) and a large proportion of body mass consist of water.
The total amount of water in the body is high and depending on the fat content, can be high as high s 60-70% of total body weight.
It also contains substantial amounts of the “major minerals,” from calcium and phosphorus down to sulfur and magnesium as well as trace quantities of most elements.
The human diet reflects this compositional need, and consists of large quantities of water containing, proteinaceous, fatty, and carbohydrate foods, as well as others rich in the minerals.
The composition of dietary fat influences lipid absorption, metabolism and tissue deposition and thereby growth and body composition.
A number of factors influence body composition, including nutrient and energy intake, sex, age and level of activity. Body composition can vary with stress and nutritional status.
The chemical changes in the body during growth depend on the availability of a nutrient substrate so nutrition can play a vital role in body composition.
Essential nutrients in adequate quantities are required to assure that the cell growth, proliferation and differentiation genetically programmed to occur can process unhindered.
Human body composition
