Proteins form muscles, bones, hair, skin, and the connective tissue that hold the body together. Proteins even make up the messengers within the body including hormones, the immune system, enzymes, and brain chemicals.
If the body does not have enough protein it will lose muscle mass, hair becomes brittle, skin sags, bones become weaker, and the immune system becomes sluggish. To add to that sex drives dwindle, anxiety and depression can set in, and you can become more likely to fall and suffer a hip fracture that you may be less likely to recover from. All of this explains why proteins are so important, and why not having enough is bad for health.
While it is true that proteins come from diet, that is not entirely accurate, proteins are made by the body. Diet is important as it supplies amino acids that are building blocks that create proteins. Not all amino acids get turned into proteins, some are turned into glucose and are burned for energy.
Protein sources go into the stomach and begin to be digested, the digestive system breaks the food protein into amino acids which go through the small intestine and into the bloodstream and are distributed throughout the body which takes the amino acids to make whatever proteins it needs such as muscle, organ cells, hormones, and so on.
Some of the protein from meat is turned into mean body mass, the rest into glucose for energy. Foods such as berries contain carbs that are burned for energy; and nuts contain fats that are also burned for energy.
Amino acids contain nitrogen, when turned into proteins the nitrogen remains in the body as part of the protein. When amino acids are converted to sugars the nitrogen is released and get passed in urine. Amino Acid Utilization can measure the amount of nitrogen in urine to determine if your food is being turned into proteins or sugars.
The best sources of dietary protein are whole eggs at 47% AAU followed by meat, poultry, and fish, at 32% AAU. Protein powders are said to be good for building muscle, but most of those only have 17% AAU, that means 83% of the protein is being turned into sugars.
The main reason people lose so much lean body mass as the age can be attributed to 3 main reasons: not eating enough protein sources; eating the wrong sources for protein; and not digesting their protein. It is not enough just to eat protein sources, those sources must be digested and broken down into amino acids. With age the digestive system becomes weaker, tending to make less stomach acid and digestive enzymes which can cause a downward spiral. Enzymes are actually proteins, if one is protein deficient it stands to reason that not enough digestive enzymes would be produced, meaning food will not be digested properly leading to further the protein deficiency and even lower enzyme production, and so on in a circle.
Amino acids can be arranged by the body in many different combinations to make thousands of proteins from 21 amino acids. By taking amino acids orally via supplements they can directly go to the bloodstream to be used to build bone, muscle, connective tissues, hormones, enzymes and more without having to rely on the digestive system to build protein. However the right amino acids in the right combination must be taken. Some amino acids are made in the body, the rest are obtained in the diet, these are called the 9 essential amino acids: Leucine, Valine, lsoleucine, Lysine, Phenylalanine,Threonine, Methionine, Tryptophan, and Histidine.
A clinical study involving 500 overweight participants put the subjects on a diet of healthy vegetables and fats. Instead of meat, fish, or dairy they were given the amino acids as a supplement as their only protein source. Subjects lost 2-16 lbs per week while maintaining muscle mass, without feelings of hunger and deprivation. Subjects also reported younger looking skin and stronger, shinier hair.
Amino acids can help improve endurance, improve hair, nails, and skin, prevent injuries, strengthen bones, boost immunity, support better moods and concentration, help to alleviate food sensitivity symptoms, and boost overall wellbeing while helping to reduce the loss of muscle mass, risk of injury and loss of mobility that comes with age.
