For the short time I worked at a gym as a personal trainer, this question came up often: I'm not a bodybuilder or an athlete, and I'm not trying to build muscle. Should I be concerned about protein consumption?
The answer is yes. Absolutely.
Proteins are used in strengthening muscles, true, but they serve other important roles in the human body as well. Protein in the form of collagen is the building block for skin, hair, ligaments, tendons, teeth, bones, and cartilage. Proteins play a role in healthy hormone and enzyme function. They are the foundation of antibodies. In times of growth (childhood, pregnancy, recovery from illness or surgery), the body relies on proteins to grow and/or repair itself.
Amino acids are the building blocks of protein. There are 9 essential amino acids; "essential" here has the same meaning as "essential vitamins": the body cannot create these amino acids and therefore must be consumed in the diet. There are 11 nonessential amino acids -- their consumption in the diet is not necessary because the body can produce them.
If the body does not get enough protein, it will rob either muscles (or worse, our carbon skeleton) of its proteins to perform the necessary tasks listed above.
A "complete protein" means that the protein source has all 9 essential amino acids; an "incomplete protein" means that the protein source does not have all 9 essential acids. All animal products are complete proteins, but be aware that sometimes, protein quality (and amino acid count) is lost in foods that are highly processed. Most plant products are incomplete proteins with these exceptions: soy, quinoa, chia seeds, buckwheat, hemp, and flax seeds. Click here to read Vegans and Protein.
But be careful, friends -- everything in balance:
Myth: As far as weight is concerned, I can't eat too much protein. Anything beyond what my body needs will be excreted through the urine.
The Science: It is true that the body has limited ability to store protein. It is also true that a portion if the protein is excreted in the urine if it is unused. However, the other portion of the protein is converted to glucose or fat, depending on the body's needs. In other words, protein consumption beyond what the body needs has the same fate as carbohydrates or fat in excess: the body turns it into fat. Additionally, individuals with kidney disease, osteoporosis, diabetes or liver disease should consult with their physician prior to adopting a high-protein diet.
So how much protein do I need? According to the RDA, the minimum daily intake to meet nutrition requirements is .8g/kg/day. If a woman weighs 130 lbs, which is 59kg, this would be 47g each day. The American College of Sports Medicine suggests that athletes consume 1.2g - 2.0g/kg/day. In other words, if the 130-lb woman is very active, she needs 70g to 118g each day.
Interested in important considerations with protein and sports performance? Click here!