High-protein diets

Lnczak-Szcznrek, A., and Flisinska-Bojanowska, A., 1977. Effect of high-protein diet on glycolytic processes in skeletal muscles of exercising rats. Journal of Physiology and Pharmacology 48 119—126. 

Nonetheless, birds have higher metabolic rates than mammals of similar size. Most small mammals reduce energy costs by seeking protected environments birds spend much of their time exposed. Also, because fat is heavy, the need to fly restricts a bird s ability to store energy. Even with a high-protein diet, a bird must eat as much as 3(1 percent of its body... 

Water birds have not been shown to be directly affected by acidification. However, the prey of waterbirds may be of concern as these lower food-chain organisms may have elevated levels of toxic metals related to acidification of their habitat. Moreover, most water birds rely on some component of the aquatic food-chain for their high protein diet. Invertebrates that normally supply caJcium to egg-laying birds or their growing chicks are among the first to disappear as lakes acidify. As these food sources are reduced or eliminated due to acidification, bird habitat is reduced and reproductive rate of the birds is affected. The Common Loon is able to raise fewer chicks, or none at all, on acidic lakes where fish populations are reduced 37 and 5S). However, in some isolated cases, food supplies can be increased when competitive species are eliminated (e.g.. Common Goldeneye ducks can better exploit insects as food when competition from fish is eliminated). The collective influences of acidification are difficult to quantify on a specific area basis but for species that rely on a healthy aquatic ecosystem to breed, acidification remains a continuing threat in thousands of lakes across eastern North America 14). 

Figure A11.2 shows how f() values vary with the protein content of the diet, for dp = 5 and dw = 2. From inspection of the Ambrose and Norr (1993) and Tieszen and Fagre (1993) data sets, we note that data from diets [B, C, D, E, F, G, 5, and 6] are more able to constrain values of d and fQ and these points are separately indicated. The smooth curves represent f() = F (complete routing), f() = (the best fit to the data), and f() = F (= 1 = scrambling). For high protein diets there is little distinetion between the eurves. Note that f() is always greater than 1, implying some protein routing.

The nutrient stress hypothesis can be tested by comparing diet-tissue A N values of animals on low versus normal and high protein diets. Our controlled diet experiments, although primarily designed to trace carbon from different dietary macronutrient fractions (proteins versus carbohydrates, fats and sugars) to animal tissues under different levels of nutrient stress (Ambrose and Norr 1993) may be suitable for testing this hypothesis because they contain diets with 5, 20 and 70% protein by weight. 

Trilok, G. and Draper, H.H. 1989a Effect of a high protein diet on acid-base balance in adult rats. 

The Newborn and the Laboratory. The wellbeing of the pre-mature infant can be ascertained by measuring blood pH, electrolytes and other blood components on a routine basis. The maintenance of these infants electrolyte balance and normal pH is shown in Figure 3. An infant placed on a high protein diet milk formula developed an acidosis, and when brought to normal pH... 

Note, if asymptomatic, just restrict fluid to between 1000 and 1200 mL/d +/- high protein diet +/- sodium chloride (NaCl) tablets ° Conivaptan may be utilized in carefully selected patients... 

Malnutrition is a significant but reversible risk factor. High-protein diets have been shown in multiple studies to improve wound healing in patients with pressure sores.37... 

Pressure relief, adequate nutrition (high-protein diet), and surgical debridement or abscess drainage are the mainstays of nonpharmacologic treatment.38... 

Dietary consumption should be balanced in carbohydrates, protein, and fat. Several diet plans exist that promote weight loss through strict limitation or overabundance of only one macronutrient (e.g., low-fat, low-carbohydrate, or high-protein diets) however, overall energy consumption and expenditure will determine the amount of weight alteration. Consultation with a dietician is recommended when... 

Calcium is essential for bones, teeth, metabolic signaling and regulation, and other bodily functions. Adults require an intake of around lg per day only about 10% of the calcium ingested is absorbed into the body - less from a low-protein diet, more from a high-protein diet. Vitamin D facilitates absorption, as does... 

Feeding human subjects meat-rich diets has been clearly and repeatedly associated with elevated urinary acid and calcium loss. Anand, et al. (12) fed college men low, medium, and high-protein diets. Fecal calcium changed less than 15%, whereas urinary calcium losses accounted for the major loss of calcium. Calcium loss and meat protein intake correlated directly. Johnson, et al. (34) reported that women showed a similar response when fed such diets. 

Since the early 1970 s, research has been directed at identifying the mechanism by which the calciuria is induced. Attention was given first to the question of whether the elevated urinary calcium excretion was caused by an increase in the intestinal absorption of calcium. Results of calcium balance studies in human subjects showed that protein ingestion either had no effect on calcium absorption (4) or that the effect was insufficient to account for the calciuria (5j. Consequently, negative calcium balance is a frequent observation in human studies when high protein diets are fed, and this situation is not improved by high calcium intakes (4 ). 

Table IV. Postprandial Effects of Ca and P Levels in High Protein Diets on Urinary Calcium Excretion of Men...

As noted in Table II, the protein content of the hepatic microsomal fractions showed an increase with diets 32% through 52% casein. These observations are consistent with the findings of other workers with rats (45, 46, 47, 48, 49). The decrease noted in the protein content of the liver fractions of fish fed the 62% casein diet has also been observed by Sachan (49) in rats fed a high protein diet. 

There is some evidence in laboratory animals that high-protein diets cause more rapid conversion of heptachlor to heptachlor epoxide and therefore increase the toxicity resulting from exposure to heptachlor. The lack of corroborating data in humans on this phenomenon, however, makes it difficult to postulate that high- or very high-protein diets would significantly increase susceptibility to heptachlor toxicity. 

To discriminate diet-dependent odors can be vital in the context of reproductive behavior. Supporting the hypothesis that animals discriminate and prefer potential mates that are in good nutritional condition, Ferkin et ah (1997) showed that meadow voles preferred odors of members of their own species that are on a high-protein diet (Table 3.2). 

Meadow vole Anal gland, urine, feces Protein, 9,15 or 25% Mate choice voles with high-protein diet preferred... 

In the normal individual a high protein intake probably does not cause increases in blood urea nitrogen (BUN). However, in the individual with even minimal renal or liver dysfunction, major increases can be observed. In a dehydrated patient with septicemia and pleural abscess after mitral valve surgery, a high-protein diet produced an increase in BUN from normal limits to 100 mg/100 ml (Dll). The serum creatinine only rose to 2.9 mg/100 ml (Dll). Hemorrhage will also create elevations in BUN. In a patient who experienced gastric hemorrhage and hypotension, the BUN rose to 135 mg/100 ml while the creatinine rose only to 2.5 mg/100 ml (Dll). 

Drug/Food interactions Theophylline elimination is increased (half-life shortened) by a low carbohydrate, high protein diet, and charcoal broiled beef (due to a high polycyclic carbon content). Conversely, elimination is decreased (prolonged half-life) by a high carbohydrate low protein diet. Food may alter the bioavailability and absorption pattern of certain sustained-release preparations. Some sustained-release preparations may be subject to rapid release of their contents when taken with food, resulting in toxicity. It appears that consistent administration in the fasting state allows predictability of effects. 

Protein has long been classified as a factor that causes Ca to be wastefully excreted from the body. Less is documented in relation to how it affects Ca absorption. Dawson-Hughes has reported that a dietary protein increase of 20% combined with a low Ca intake of 800 mg/day in elderly men and women lowers the amoimt of absorbable Ca by 23%. In contrast, a high protein diet (between 18.16% and 29.14% of total dietary energy from protein) in the presence of a high Ca intake... 

A high-protein diet is of debatable value. Since increased protein intake seems to have a theoretic adverse effect on renal function in some disease... 

The classical niacin deficiency disease is pellagra, which is characterized by symptoms including diarrhoea, dermatitis, dementia and eventually death. High-protein diets are rarely deficient in niacin since, in addition to the preformed vitamin, such diets supply sufficient tryptophan to meet dietary requirements. Large doses of niacin can cause the dilation of capillaries, resulting in a painful tingling sensation. 

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