Protein daily intake

Copper is an essential trace element. It is required in the diet because it is the metal cofactor for a variety of enzymes (see Table 50—5). Copper accepts and donates electrons and is involved in reactions involving dismu-tation, hydroxylation, and oxygenation. However, excess copper can cause problems because it can oxidize proteins and hpids, bind to nucleic acids, and enhance the production of free radicals. It is thus important to have mechanisms that will maintain the amount of copper in the body within normal hmits. The body of the normal adult contains about 100 mg of copper, located mostly in bone, liver, kidney, and muscle. The daily intake of copper is about 2—A mg, with about 50% being absorbed in the stomach and upper small intestine and the remainder excreted in the feces. Copper is carried to the liver bound to albumin, taken up by liver cells, and part of it is excreted in the bile. Copper also leaves the liver attached to ceruloplasmin, which is synthesized in that organ. 

An overall osteoprotective effect is associated with soy diets, the major active component being the isoflavones although the contribution (if any) of soy protein has to be clarified. The spine, rather than the femur, appears to be the most consistently protected bone site. The average daily intake in Japanese women is around 50 mg/day and appears to be sufficient to have a long-term protective effect on the spine. In non-Asian, postmenopausal women, the demonstrated effective dose is 80-90 mg/day. In future clinical studies, investigating the effect of isoflavones on bone metabolism, larger scale, randomized, controlled, intervention trials for longer time periods (1-3 years) will be necessary with a standardized source of soy protein/isoflavones and... 

Table 8.6 Recommended daily intake of high-quality protein for infants, children, teenagers and adults...

A growing number of studies report on the occurrence of PFCs in food. The outcome of these studies has been related to potential dietary intake and exposure levels (mainly by the estimation of the daily intake). Most selected examples from the literature can be seen in Table 2. It is important to remark that PFOS and PFOA tend to bind to certain proteins rather than bioconcentrate in fat, but they have also some potential to bioaccumulate in the food chain. 

Place the patient on a nutritionally balanced, reduced-calorie diet that contains approximately 30% of calories from fat. Distribute the daily intake of fat, carbohydrate, and protein over 3 main meals. If a meal is occasionally missed or contains no fat, the dose of orlistat can be omitted. 

Zinc plays a number of important roles in the body and deficiency results in serious adverse effects. Recommended daily intake is 12 to 15 mg. Zinc is very common in the environment and readily available in many foods, including grains, nuts, legumes, meats, seafood, and dairy products. Numerous enzymes require zinc, as do proteins that regulate gene expression. Zinc plays a role in the immune system and is also important in the development and function of the nervous system. 

Consumption by postmenopausal women (6-month parallel-group design) of soy protein (40g/day providing either 56 mg isoflavones/day or 90 mg isoflavones/day) compared to cesin and nonfat dry milk (40g/day) produced significant increases in bone mineral content and density in the lumbar spine (but not in any other parts of the body), but only in the higher isoflavone (90 mg/day) group compared to the control group.Daily intake for 2 years of... 

It is estimated that the average daily intake is about 14 mg, but the increasing use of highly refined foods may lead to dangerously low consumption. Recent interestd f has been aroused by studies that show that much larger amounts of vitamin E (e.g., 100-400 mg/day) substantially reduce the risk of coronary disease and stroke in both womens and menh and also decrease oxidative modification of brain proteins.1 The decrease in heart attacks and stroke may be in part an indirect effect of the anticlotting... 

The beneficial effects of dielary fiber, including both soluble and insoluble fiber, are generally recognized. Current recommendations arc for daily intakes of 20-35 g in a balanced diet of cereal products, fruits, vegetables, and legumes. However, the specific preventive role of dietary fiber in certain diseases has been difficult to establish, in pan because dielary risk factors such as high saturated fat and high protein levels are reduced as fiber levels increase. 

For many populations, the exact amino acid composition of a particular food is not particularly important. The daily intake of total protein is very high, and the protein sources are varied enough that limiting amino acids do not come into play. However, for a variety of specific situations, determination of amino acid content is important. A list of these situations was first articulated by Baxter (2) and will be partially recapitulated here. 

Dietary requirements for AAs and protein usually are stated as proportions of the diet. However, the level of feed consumption has to be taken into account to ensure that the total intake of protein and AAs is appropriate. The protein and AA requirements derived by the NRC (1994) relate to poultry kept in moderate temperatures (18-24°C). Ambient temperatures outside of this range cause an inverse response in feed consumption i.e. the lower the temperature, the greater is the feed intake and vice versa (NRC, 1994). Consequently, the dietary levels of protein and AAs to meet the requirements should be increased in warmer environments and decreased in cooler environments, in accordance with expected differences in feed intake. These adjustments are designed to help ensure the required daily intake of AAs. 

Faist et al.292 have also examined the effect of dietary CML on the expression of GST in the rat kidney. In their Study 1, casein-linked CML was administered at two pharmacological doses [110 and 300 mg CML per kg body weight (b.w.) per day] for 10 d. In Study 2, supplementary breadcrust was used to give a daily intake of 11 mg (kg b.w.) 1 d for 42 d. In Study 1, the glutathione level in the kidneys increased 43 and 65%, respectively, and Phase II GST activity increased 12 and 96%, respectively, over the control. In Study 2, the protein content of the isoenzyme GST In- increased, but that of lji- and la-1 remained the same as in the control. Both studies were supported by experiments on Caco-2 cells. Exposure to purified CML... 

The accepted amount of protein required to maintain nitrogen balance is 28 g per day for a 70-kg person, i.e, about 3,8 g of nitrogen. This is estimated by measuring the N excretion over 6 to 7 days on a protein-free diet. If the protein source is from cereal, then the daily intake would have to be increased to about 40 g per day for a 70-kg person. The difference is due to the variable amounts of essential amino acids found in proteins. The amount required by growing children is larger the accepted figure is about 0.6 g per kilogram per day. 

Another significant problem associated with consumption of microbial cells is their high content of nucleic acid (NA) which ranges from 8 to 25 gms nucleic acid per 100 gms protein and most of the nucleic acid is present as RNA (55). Before single-cell protein can be used as a major source of protein for human consumption, the content of nucleic acid has to be reduced, so that the daily intake of nucleic acid from yeast would not exceed 2 gms (i.e. 20g yeast). Higher quantities cause uricemia and continued ingestion of SCP may result in gout (56,57). 

Chemical groups containing sulphur (chemical notation SH) that are vital in proteins and structures. They are targets for toxic chemicals, tolerable daily intake (TDI)... 

I he average daily intake of total dietary cholesterol is 400-500 mg. Cholesterol also enters the gastrointestinal tract via the bile. Between fiOO and 1200 mg of free cholesterol is secreted in the bile per day. By weight, bile consists of 92% water, 6% bile salts, 0,3% cholesterol, and small amounts of bilirubin, fatty acids, phosphatidylcholine, and sails. The cholesteryl esters of the diet are hydmlyzed to free cholesterol and a fatty add by pancreatic cholesterol esterase. After entry into the enterocyte, the free cholesterol is nmverted back to cholesteryl esters by acyl CoA cholesterol acyl transferase. Some evidence suggests that the absorption of dietary cholesterol (from the bile salt micelles) is mediated by a membrane-bound transport protein of the brush border (1 humhofer and Hauser, 1990),... 

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