Dietary components protein

A DIFF relates a specified body component isotopic composition to the various compositions of a specified and complete set of dietary components. The complete diet must be accounted for in the DIFF, but it can be partitioned in any way that seems sensible for example, into individual amino acids or into protein, carbohydrate and lipid, etc. 

Before proposing a general formulation, we illustrate a DIFF with a simple case, in which we consider bone collagen as the body component, and the diet as containingjust two components, protein and non-protein. In the notation, B stands for body 5 values, and D for diet 8 values suffixes distinguish the particular component specified. Thus Bcolla stands for the collagen 8 C, Dp and Dn for the dietary protein and non-protein 6 C values. 

The data sets presented by Ambrose and Norr (1993) and Tiezsen and Fagre (1993) record analyses of rodents fed on diets in whose dietary components have been analyzed. Thus D and F are given for the diets, (generally for the protein, carbohydrate and lipid components sometimes in more detail), and have been varied so as to relate to the corresponding change in B. Measurements were made on animals thought to have reached an overall steady state. 

The standard diet used in our experiments is a semipurified, cholesterol-free preparation that is composed of 25% protein, 40% sucrose, 13% coconut oil, 1% corn oil, 15% cellulose, 5% mineral mix, and 1% vitamin mix. This diet has been shown to induce an endogenous hypercholesterolemia and lead to atherosclerosis in rabbits and monkeys (4, 5). The specific question addressed by our series of investigations is whether the type of dietary protein, when all other dietary components are constant, can influence the development of hyperlipoproteinemia and atherosclerosis. More specifically, we have examined the effects of the individual amino acids, lysine and arginine, and their ratios in the diet on plasma and hepatic lipids as well as the development of arterial plaques. 

In addition to energy reserves, many other types of biochemicals are required to maintain an organism. Cholesterol is required for cell membrane structure, proteins for muscle contraction, and polysaccharides for the intracellular matrix, to name just a few examples. These substances may be produced from transformed dietary components. 

Before 1900, many experiments suggested that dietary components other than protein, carbohydrate, fat and minerals were needed for survival. However, it was Frederick Gowland Hopkins who provided the evidence that minute amounts of unknown substances, present in normal foods, were essential for normal healthy life. His eminence in the scientific community ensured that the work and ideas were accepted he was awarded the Nobel Prize for his work in 1929. 

Interest in dietary components which explain differences in breast cancer rates comes from strong correlations between nutrient supply within nations and their age-adjusted rates for breast cancer (11). The most frequently cited dietary components related to higher risk of breast cancer are total fat, total protein, calories, animal fat, animal protein, and a lack of fiber. Overall it has not been possible to identify the specific dietary constituents responsible for the observed incidence since the intakes of many dietary factors such as protein, fat, and calories are strongly intercorrelated. Other studies of nutrient intake and breast... 

A functional food is one that offers a benefit over and above its nutritional value. Our body needs an intake of six essential dietary components in order to sustain life and regenerate cells they are carbohydrates, proteins, fats, vitamins, minerals, and water. Many meals provide most or all of them. A functional food has to offer something extra and not just more of one of these essential components, and it must actively promote the health of those who consume it. Merely fortifying a food with calcium or vitamin C does not turn it into a functional food. Most breakfast cereals have added iron, and adding more iron in the form of iron powder to make Kellogg s Special K does not make this a functional breakfast cereal. 

Limited data are available about the effects of individual dietary components on absorption, and consequently the requirement, of Mn. Dietary protein and phosphorus levels (33), calcium level (34) and the effect of a partial substitution of soy protein for meat (28) have been tested in balance studies without any obvious effect of Mn absorption or retention. However, since the main route of excretion is via the bile, the conventional balance technique is probably not sensitive enough to identify dietary factors that influence Mn absorption. 

Absorption studies have been conducted using several dietary treatments. One dietary approach has been to use purified diets with egg albumen as the protein source. This approach reduces of day to day and between subject variability in the nutrient content of diets. It is well suited for use when levels of specific nutrients or dietary components must be carefully controlled and/or varied without changing any other factors in the diet. Since all other dietary components remain constant, any differences found between treatments can be ascribed to the altered nutrient under study. 

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