The Importance of Getting Enough Dietary Protein

Protein is an essential macronutrient that plays a crucial role in maintaining overall health and well-being. Proteins are comprised of amino acids, which are often referred to as the building blocks of life, as it is responsible for supporting various body functions and processes.

Protein is vital for the structure, function, and regulation of organs and tissues. Proteins support the cytoskeleton of cells and play a key role in the synthesis of collagen, an essential structural protein. Enzymes, which are proteins, facilitate the chemical reactions necessary for cellular, tissue, and organ function. Proteins like insulin act as hormones, while antibodies are proteins that support the immune response to infection. The detoxification system within the liver relies on proteins for metabolic regulation and protein synthesis.

One of the key roles of protein in the body is its contribution to the production of hormones and neurotransmitters. Hormones are chemical messengers that regulate numerous bodily functions, such as metabolism, growth, and reproduction. Neurotransmitters play a crucial role in communication between nerve cells in the brain and are essential for mood regulation, cognition, and motor function.
Protein is also essential for the maintenance of bones and muscles. Bones require protein for constant rebuilding, while muscles, primarily made up of protein, rely on adequate intake for growth, repair, and strength.

The Recommended Dietary Allowance (RDA) for dietary protein intake is 0.8 g/kg of body weight per day. While this recommendation prevents deficiency, optimal protein requirements may vary based on factors like age, activity level, and overall health. As we age, protein requirements tend to increase due to decreased muscle mass, reduced nutrient absorption, and changes in metabolism. Seniors may need around 1.0-1.2 grams of protein per kilogram of body weight per day. Endurance athletes (those who participate in activities like running, cycling, or swimming regularly) generally need to consume 1.2 to 1.4 grams of protein per kilogram of body weight per day.

When the body does not receive enough protein, it can lead to health issues like muscle loss, weakened immune function, poor wound healing, and fatigue. Long-term protein deficiency can increase the risk of conditions like osteoporosis and sarcopenia.

Protein should comprise about 20-30% of daily caloric intake according to the Institute for Functional Medicine. High-protein foods include lean meats, poultry, fish, eggs, dairy products, legumes, nuts, and seeds. Resources like the USDA National Nutrient Database and nutrition labels on packaged products can help determine the protein content of various foods. Various supplements can also support protein requirements. Common types of protein supplements include whey, casein, collagen, and plant-based proteins like pea, soy, rice, and hemp, each offering distinct benefits.

The Digestible Indispensable Amino Acid Score (DIAAS) is a method used to evaluate the quality of dietary proteins by measuring the digestibility of each individual indispensable (essential) amino acid at the end of the small intestine, specifically the ileum. A DIASS score, indicating protein quality based on amino acid composition and digestibility, is beneficial for choosing high-quality protein sources. However, a readily accessible database for DIASS scores is still in development and not required on food labels.

In conclusion, protein is crucial for supporting many of the body’s structures, functions, and the regulation of organs and tissues. Meeting optimal protein requirements is vital for overall health and well-being, especially as we age. By incorporating protein-rich foods into a balanced diet, individuals can ensure they meet their body’s needs and support optimal health.

References:
Moughan PJ, Lim WXJ. Digestible indispensable amino acid score (DIAAS): 10 years on. Front Nutr. 2024 Jul 3;11:1389719. doi: 10.3389/fnut.2024.1389719. PMID: 39021594; PMCID: PMC11252030.
Wolfe RR, Rutherfurd SM, Kim IY, Moughan PJ. Protein quality as determined by the Digestible Indispensable Amino Acid Score: evaluation of factors underlying the calculation. Nutr Rev. 2016 Sep;74(9):584-99. doi: 10.1093/nutrit/nuw022. Epub 2016 Jul 24. PMID: 27452871; PMCID: PMC6322793.