Protein: The Building Blocks of Life

The foundational structure of the human body is protein. It is common knowledge that muscles are largely comprised of this substance, but where else does protein play a role? Bone, skin, hair, organs, and even the immune system need protein for structure and proper function. It is essential that we consume adequate dietary protein to maintain these structures and functions. Sufficient protein in the diet also helps with satiety and improving the muscle: fat mass ratio.

There are several methods to estimate the protein needs. The US RDA (Recommended Daily Allowance) for dietary protein is 0.8 grams protein/kg body weight/day (about 0.4grams/pound body weight/day). However, individual needs can vary based on level of physical activity, age, and certain health conditions. Research supports the following protein intake related to levels of physical activity: 1.0 grams/kg /day with light activity; 1.3 grams/ kg/day with moderate activity; 1.6 grams/kg/day with intense activity.

There is evidence that higher protein consumption (1.2-1.6 grams/kg/day) can minimize the age-related loss of muscle mass (sarcopenia) which can lead to frailty in aging adults. If kidney function is impaired or other health conditions are present, advice from a health care provider regarding individual protein needs should be sought.

What are some general guidelines for targeting adequate protein intake? Consuming a portion of protein-rich food the size of the palm of your hand at lunch and at dinner, plus one or two ounces of protein at breakfast, will provide optimal protein for most people. Another helpful visual aid is to fill about ¼ of your plate with protein-rich foods: Beef, pork, poultry, fish, eggs; milk and milk products are additional animal sources of protein. Remember that plant foods such as legumes (beans, peas, lentils), soy products, nuts, and seeds are rich sources of protein and provide the added benefit of fiber and phytonutrients that are only supplied from plants. The proteins found in grains and vegetables contribute to overall protein consumption as well.

Remember to choose a variety of protein sources in your diet. Variety really is “the spice of life”!

References: Appl Physiol Nutr Metab, 2016 May;41(5):565-72.doi: 10.1139/apnm-2015-0550. Epub 2016 Feb 9.

Protein "requirements" beyond the RDA: implications for optimizing health

National Institute of Health,  https://pubmed.ncbi.nlm.nih.  Dietary Protein Intake and Human Health