Proteins are different combinations of Amino Acids, and Amino Acids are often referred to as the “building blocks of life”. Our body makes gazillions of proteins and there are 10’s of thousands of different types of proteins, and all of these are combinations of Amino Acids. There are about 20 (the science varies a bit) essential amino acids, our body cannot make them we have to eat them, if we don’t we would get sick and eventually die. Both plant and animal foods contain proteins from which we can obtain these essential amino acids. Animal sourced protein contains all the essential amino acids.
How Much Protein Do We Need To Eat
Adults do not require protein for growth. This being said we lose some protein from our body everyday. Cells die and are replaced, some protein is recycled, and some is lost. The science on how much protein we need to eat varies a bit, but if we take what has been published and take the highest then the amount is 0.8 grams of protein per kilogram of body weight. So a person weighing 70Kg would require 56 grams of protein.
What Happens If We Eat More Protein Than We Need
Our body's preferred food is glucose. If our body’s glucose reserves are depleted our cells will start using fat for fuel, and last but not least will use protein. Even when we have fat storage left some protein will be lost to be converted into glucose to make sure that red blood cells and to a lesser extent the brain have an adequate glucose supply. When we eat more total food than we need the excess no matter whether it carbs, fat or protein it is converted into and stored as fat.
If we are not overeating, and our diet is made up of a lot of protein then it is converted to an “amino sugar” and then into molecules called Ketone Bodies. All our cells, with the exception of red blood cells can use this molecules for food. When glucose reserves are low our bodies will use fat before protein for energy. This is necessary since there is no storage mechanism for excess protein. If bodily protein is required for energy muscles are scavenged by it to obtain the energy. Protein is essential, but not for immediate energy supply or energy storage.