Introduction
editThis is where I will be making potential edits to the Protein (nutrient) page. I have been researching this information for the better part of a semester and believe the it would add to a complete page. I have copied the relevant section from the article and bolded my proposed additions.
Excess Consumption
editThe U.S. and Canadian Dietary Reference Intake review for protein concluded that there was not sufficient evidence to establish a Tolerable upper intake level, i.e., an upper limit for how much protein can be safely consumed.[1]
The body is unable to store excess protein. Dietary protein is converted to individual amino acids by the digestive process, which are then absorbed. When amino acids are in excess of needs the liver takes up the amino acids and subjects them to deamination, a process that converts the nitrogen from the amino acids into ammonia, further processed in the liver into urea via the urea cycle. Excretion of urea is performed by the kidneys. Other parts of the amino acid molecules can be converted into glucose and used for fuel.[2][3][4] When food protein intake is periodically high or low, the body tries to keep protein levels at an equilibrium by using the "labile protein reserve" to compensate for daily variations in protein intake. However, unlike body fat as a reserve for future caloric needs, there is no protein storage for future needs.[1]
Research has supported a theory that excessive intake of protein increases calcium excretion in urine, occurring to compensate for the pH imbalance from oxidation of sulfur amino acids. This may lead to a higher risk of kidney stone formation from calcium in the renal circulatory system.[1] In theory, this calcium excretion from bone resorption could contribute to osteoporosis, but a meta-analysis by the National Osteoporosis Foundation reported no adverse effects of higher protein intakes on bone density[5] A meta-analysis reported a small decrease in systolic and diastolic blood pressure with diets higher in protein, with no differences between animal and plant protein.[6]
High protein diets have been shown to lead to an additional 1.21 kg of weight loss over a period of 3 months versus a baseline protein diet in a meta-analysis by the European Journal of Clinical Nutrition. Benefits of decreased BMI as well as HDL cholesterol were more strongly observed in studies with only a slight increase in protein rather than closer to the extreme trials where high protein was classified as 45% of total energy intake. Detrimental effects to cardiovascular activity were not observed in short-term diets of 6 months or less.[7] There is little consensus on the potentially detrimental effects to healthy individuals of a long-term high protein diet so caution should be exercised when using this as a form of weight loss.[7][8][9][10]
The 2015–2020 Dietary Guidelines for Americans (DGA) recommends that men and teenage boys increase their consumption of fruits, vegetables and other under-consumed foods, and that a means of accomplishing this would be to reduce overall intake of protein foods.[11] The 2015 - 2020 DGA report does not set a recommended limit for the intake of red and processed meat. While the report acknowledges research showing that lower intake of red and processed meat is correlated with reduced risk of cardiovascular disease in adults, it also notes the value of nutrients provided from these meats. The recommendation is not to limit intake of meats or protein, but rather to monitor and keep within daily limits the sodium (< 2300 mg), saturated fats (< 10% calories per day), and added sugars (<10 % calories per day) that may be increased as a result of consumption of certain meats and proteins. While the 2015 DGAC report does advise a reduced level of consumption of red and processed meats, the 2015-2020 DGA key recommendations only go as far as to recommend that a variety of protein foods be consumed, including both vegetarian and non-vegetarian sources of protein.[12]
Dietary Recommendations
editSpecial Populations
editChronic Kidney Disease
editWhile there is no conclusive evidence that a high protein diet can cause CKD, there seems to be a strong consensus that those suffering from the disease should decrease consumption of protein. CKD patients who reduce protein consumption decrease occurrence of renal death by 32% versus the CKD patients who do not take these measures.[13][14] Moreover, a low protein diet (0.6 g/kg/d - 0.8 g/kg/d) in this population has been shown to lead to metabolic processes that may preserve kidney function. Conversely, a low protein diet in these patients has caused additional complications such as malnutrition in some subjects.[14]
Reflist
edit- ^ a b c "Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients)". 2005-10-28. doi:10.17226/10490.
{{cite journal}}: Cite journal requires|journal=(help) - ^ Tarnopolsky, M. A.; Atkinson, S. A.; MacDougall, J. D.; Chesley, A.; Phillips, S.; Schwarcz, H. P. (November 1992). "Evaluation of protein requirements for trained strength athletes". Journal of Applied Physiology (Bethesda, Md.: 1985). 73 (5): 1986–1995. doi:10.1152/jappl.1992.73.5.1986. ISSN 8750-7587. PMID 1474076.
- ^ Ten Have, Gabriella A.M.; Engelen, Marielle P.K.J.; Luiking, Yvette C.; Deutz, Nicolaas E.P. (2007). "Absorption Kinetics of Amino Acids, Peptides, and Intact Proteins". International Journal of Sport Nutrition and Exercise Metabolism. 17: S23–S36.
- ^ Smith, Jack L.; Gropper, Sareen Annora Stepnick; Groff, James L. (2009). Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Cengage Learning. ISBN 0-495-11657-2.
- ^ Shams-White MM, Chung M, Du M, Fu Z, Insogna KL, Karlsen MC, LeBoff MS, Shapses SA, Sackey J, Wallace TC, Weaver CM (2017). "Dietary protein and bone health: a systematic review and meta-analysis from the National Osteoporosis Foundation". Am. J. Clin. Nutr. 105 (6): 1528–1543. doi:10.3945/ajcn.116.145110. PMID 28404575.
- ^ Rebholz CM, Friedman EE, Powers LJ, Arroyave WD, He J, Kelly TN (2012). "Dietary protein intake and blood pressure: a meta-analysis of randomized controlled trials". Am. J. Epidemiol. 176 Suppl 7: S27–43. doi:10.1093/aje/kws245. PMID 23035142.
- ^ a b Santesso, N.; Akl, E. A.; Bianchi, M.; Mente, A.; Mustafa, R.; Heels-Ansdell, D.; Schünemann, H. J. (July 2012). "Effects of higher- versus lower-protein diets on health outcomes: a systematic review and meta-analysis". European Journal of Clinical Nutrition. 66 (7): 780–788. doi:10.1038/ejcn.2012.37. ISSN 1476-5640. PMC 3392894. PMID 22510792.
{{cite journal}}: CS1 maint: PMC format (link) - ^ Schwingshackl, Lukas; Hoffmann, Georg (2014). "Comparison of high vs. normal/low protein diets on renal function in subjects without chronic kidney disease: a systematic review and meta-analysis". PloS One. 9 (5): e97656. doi:10.1371/journal.pone.0097656. ISSN 1932-6203. PMC 4031217. PMID 24852037.
{{cite journal}}: CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link) - ^ Ko, Gang Jee; Obi, Yoshitsugu; Tortorici, Amanda R.; Kalantar-Zadeh, Kamyar (January 2017). "Dietary protein intake and chronic kidney disease". Current Opinion in Clinical Nutrition and Metabolic Care. 20 (1): 77–85. doi:10.1097/MCO.0000000000000342. ISSN 1473-6519. PMID 27801685.
- ^ Frank, Helga; Graf, Julia; Graf, Juliane; Amann-Gassner, Ulrike; Bratke, Renate; Daniel, Hannelore; Heemann, Uwe; Hauner, Hans (December 2009). "Effect of short-term high-protein compared with normal-protein diets on renal hemodynamics and associated variables in healthy young men". The American Journal of Clinical Nutrition. 90 (6): 1509–1516. doi:10.3945/ajcn.2009.27601. ISSN 1938-3207. PMID 19812175.
- ^ "Some individuals, especially teen boys and adult men, also need to reduce overall intake of protein foods by decreasing intakes of meats, poultry, and eggs and increasing amounts of vegetables or other under-consumed food groups." in "2015 – 2020 Dietary Guidelines for Americans: Shifts Needed To Align With Healthy Eating Patterns: A Closer Look at Current Intakes and Recommended Shifts: Protein Foods" (8 ed.). U.S. Department of Health and Human Services and U.S. Department of Agriculture. December 2015. Retrieved January 9, 2016.
- ^ Agata, Dabrowska, (2016-02-02). "Dietary Guidelines for Americans: Frequently Asked Questions". Digital Library.
{{cite journal}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link) - ^ Fouque, Denis; Laville, Maurice (2009-07-08). "Low protein diets for chronic kidney disease in non diabetic adults". The Cochrane Database of Systematic Reviews (3): CD001892. doi:10.1002/14651858.CD001892.pub3. ISSN 1469-493X. PMID 19588328.
- ^ a b Schwingshackl, Lukas; Hoffmann, Georg (2014). "Comparison of high vs. normal/low protein diets on renal function in subjects without chronic kidney disease: a systematic review and meta-analysis". PloS One. 9 (5): e97656. doi:10.1371/journal.pone.0097656. ISSN 1932-6203. PMC 4031217. PMID 24852037.
{{cite journal}}: CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link)