Foods are rarely promoted for their high fat or sugar content, but some products do boast a high protein content. Is the glorification of proteins justified or are the health risks of excessive protein consumption just as great as with an equally large percentage overconsumption of fats/sugars?
Answer
The protein requirement of a healthy adult is estimated at 1 gram per kg of body weight per day. There is usually much more in our diet. What we eat more than necessary we can burn (just like fats and carbohydrates) to provide energy.
If you burn fats and carbohydrates you get (to put it very simplistically) water and CO2 as end products. You can easily dump it. The situation is different for proteins because of the nitrogen that is incorporated in them as an amine group (NH2-). You lose that less easily.
When your body burns proteins, you have to remove the amine group from the amino acid (the building blocks of proteins). That produces the extremely toxic ammonia. The liver converts this directly into the less toxic urea which is then excreted by the kidneys. With a healthy liver and kidneys this is not a problem.
People with kidney and liver disorders often need to have a protein-restricted diet for that reason.
However, it must be ensured that there is no shortage of the so-called essential amio acids: these are amino acids that our body cannot produce itself and therefore must be included in the diet.
Incidentally, there are two other ways to excrete nitrogen: the waste product creatinine from muscle metabolism and uric acid from DNA/RNA metabolism.
Answered by
Dr Mistiaen Wilhelm
Prinsstraat 13 2000 Antwerp
http://www.uantwerpen.be
.