Fundamentals of Human Nutrition/Dietary intake

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5.5 Dietary Intake:PROTEIN[edit]

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5.5.1 Excess[edit]

The recommended dietary allowance (RDA) for an average person is 0,8g/kg, but some groups may need a higher amount (such as childres, women during pregnancy and lactation, or athletes). An upper level has been set at 30% of the total calorie intake. [1]

There are three main risks associated with high protein diets: dehydration, kidney damage and bone damage.

- Dehydration occurs by the need to excrete large amounts of urea and other nitrogenous wastes from protein catabolism. It can be prevented by increasing fluid consumption. [1]

- Kidney damage has been proved in people with prior renal problems. Kidneys would not be able to eliminate all the waste products of protein metabolism. However, no studies have shown significant proof of this link in healthy individuals. [1] [2]

- Bone damage has been a controversial topic over the last years. Some studies claim catabolic effect and others claim anabolic effect. Those that claim catabolic effect (lose of bone density) blame the acids generated by the oxidation of aminoacids. These acids would destabilize the acid-base balance. In order to excrete the excess acid load, the bone will release calcium, magnesium and other compounds to serve as the buffers. Studies claiming anabolic effect point at the intake of fruits, vegetables and dietary calcium to balance out the excess of acid. [1] [3-7]


[1] Sareen Grooper, Jack Smith (2009). Advanced Nutrition and Human Metabolism.

[2] William Martin, Lawrence Armstrong and Nancy Rodriguez (2005). Dietary protein intake and renal function. Retrieved from

[3] Uriel Barzel, Linda Massey (1998). Excess dietary protein can adversely affect bone. Retrieved from

[4] Robert Heaney (1998). Excess dietary protein may not adversely affect bone. Retrieved from

[5] Bess Dawson-Hughes (2003). Interaction of dietary calcium and protein in bone health in humans. Retrieved from

[6] Robert Heany and Donald Layman (2008). Amount and type of protein influences bone health. Retrieved from

[7] Robert McLean et al. (2011). Dietary acid load is not associated with lower bone mineral density except in older men. Retrieved from

5.5.2 Insufficiency[edit]