Why consuming adequate protein is vital for maintaining your daily health and quality of life
The human body is predominantly made up of proteins that are continuously being created, destroyed, converted, deconstructed, and reconstructed.
Proteins are chains of amino acids (a.k.a. building blocks) linked together via peptide bonds.
Nitrogen, found in amino acids, is used for the body to facilitate growth and reproduction.
All protein chains are not formed the same and each sequence has a specific function within the body.
Protein’s Primary Functions
- It’s used to create/repair ligaments, tendons, hair, nails, muscles, teeth, and organs
- Participates in many functions such as waste removal, healing, and growth
- Maintains the body’s immunity via antibodies that are created with proteins
- Helps build and maintain muscular and tissue structure
- Participates in numerous functions e.g. acting as enzymes for digestion
- Helps maintain blood acid-base balance and fluid balance in the body and cells
- Provides many elements of the blood and helps it clot
- Transports substances around the body such as nutrients, iron, and oxygen
- If needed, but not preferably, it can be used as an energy source
- Helps the body produce enzymes for digestion and energy creation
- Helps makeup many hormones that regulate body functions e.g. blood glucose control
Amino Acids – Building Blocks
- There are twenty different amino acids used in the body to create proteins
- Proteins cannot be formed if they do not have the required amino acids
- A well-balanced diet will provide the body with the essential building blocks it needs
Amino acids - three categories:
- Essential - can either not be created within the body or enough cannot be created to meet the bodies needs, so they must be consumed in the diet
- Non-Essential - can be created within the body
- Conditional - are non-essential amino acids that become essential during times that the body requires higher quantities than it is able to produce. For example, during wound healing, childhood, and or pregnancy. Additionally, if a person has PKU (Phenylketonuria) the body cannot produce tyrosine, therefore tyrosine becomes essential and must be consumed.
Daily Protein Needs
An individual’s daily protein needs differ as much as we do individually and our protein needs are dependent upon many factors. This is why Registered Dietitians (RDs) calculate specific protein needs for their clients/patients using evidence based recommendations and each individual’s specific data.
When RDs calculate protein needs for an adult, the recommendations would be based upon age, gender, current health conditions, current medications/side effects, current weight, current activity level, and any other important factors. For example, an underweight 70-year-old woman recovering from open heart surgery would have significantly higher protein needs than a healthy average weight 70-year-old woman that walks briskly twice a week.
For the U.S. general public, the RDA (Recommended Daily Allowance) recommends the following to maintain a "healthy" adult body: 0.8 g (grams) protein per kg (kilogram) of bodyweight. For example, a 130-pound person (divide pounds by 2.2 for kg) would need approximately 47 g of protein daily. This recommendation is often debated by professionals because they feel it only provides the basic protein needs to keep the body from becoming ill and does not fully meet the true needs of the body.
Some of the situations that can increase an individual’s protein needs are:
- Specific age groups such as infants, children, adolescents, and older adults
- Wound healing
- Many chronic diseases
- Many types of medications
Additionally, some medical conditions actually decrease an individual's protein needs such as chronic kidney disease.
Unless you have identified increased protein needs, more is not always better. Too much protein can cause excess nitrogen leading to kidney damage, increased excretion of calcium from the body, and an increased risk of kidney stones.
The DRIs (Dietary Reference Intakes), from the USDA (United States Dept. of Agriculture), provide the recommended average daily nutrient intake for healthy individuals*. It is important to note that the recommendations are for "healthy" individuals, which indicates no deficiencies, diseases, obesity, and many other indicators based on age, gender, etc. for each specific group.The DRI, recommends protein by g (grams)/d (day) and the specific recommendations are broken-down into the following groups:
- Pregnancy, and
*Click Nutritional Armor Blog about DRI and link to calculate your daily recommendations
Food Protein Sources
- Nuts and Seeds
- Beans and Peas
- Meat and Poultry
- Soy products
Please see table below for the grams of protein provided by a sample of protein sources.
Protein Per Serving
From a protein quality standpoint, we often hear about complete and incomplete proteins. This does not mean that one is better than the other, it simply means that complete proteins, such as eggs and dairy, have adequate levels of all essential amino acids and that incomplete proteins are either missing some or are limited in them.
It is key that your diet includes a variety of protein sources to allow the body to acquire adequate levels of all essential amino acids. Some years ago, it was recommended that different protein sources that “complement” each other be consumed at the same meal. Currently, the recommendation is to consume the "complementary" proteins within the same day to provide the body with adequate essential amino acid levels.
For example, pinto beans, a legume, are high in lysine but low in methionine. If pinto beans were your only source of protein that day, you would be missing adequate levels of two essential amino acids. However, if that same day you also consumed brown rice, a whole grain, that is low in lysine but high in methionine you would have provided the body with adequate levels of both methionine and lysine because the different proteins made up for each others shortcomings.