How much Protein should I consume?

Well, the answer to this question resembles many relationships....it's complicated.

1 in 3 Americans, 50 plus do not meet the recommended protein intake says a 2018 study published in the Journal of Nutrition, Health & Aging.  The study, conducted by Ohio State University and Abbot Health Care, evaluated protein intake in relation to diet patterns and functional outcomes in 11,680 adults aged 51 and older.  What they found was that 1 in 3 adults were not meeting the current daily recommended amount of 0.8 g/k/24hrs of protein.

What were the causes of the protein deficiency found by the study?   

Older adults are consuming less food which can be symptoms of reduced energy needs, genetic predisposition for low appetite, age & disease related anorexia, physical and mental disabilities which limit acquiring and preparing food, food insecurity, financial and social limitations or dental issues.  

So who is at risk for protein deficiency? 

This is not to say that men are not at risk, however the study found that women were at a higher risk of protein deficiency than men.  The study also found that single/divorced/widowed individuals, Non-Hispanic Blacks and adults with education levels between 9th grade and High School/GED were at greater risk for protein deficiency.   

 Why should I be concerned about protein deficiency? 

The study found that those who were protein deficient experienced functional limitations such as stooping, crunching, kneeling, standing for long periods of time, pushing or pulling large objects when compared to cohorts that met protein intake requirements.  Researchers also found that those who did not meet protein requirements had a much higher risk of being nutritionally deficient in other areas such as Vitamin D (96.4%) Choline (96.2%) Vitamin E (93%) and so on. 

As we age, the protein needs to maintain muscle mass, are higher for older adults than they are for younger individuals.  After the age of 30, aged related muscle wasting can set in, which is called Sarcopenia. Regardless of gender, race or ethnicity, we all naturally start to lose some muscle mass. Adults start to lose between 3%-5% of muscle each decade.  Sedentary individuals lose 20%-40% of their muscle mass over the course of adult life. After 50 yoa, decline in muscle mass increases even more.  Muscle strength also declines by approx. 15% per decade in the fifth, sixth, and seventh decades. As shown in the graph, there are a number of other factors which may cause loss of muscle mass.

So how much protein should I consume?

Protein consumption requirements vary by age, gender, physical activity levels, physical activity type, and even the time of day.  If you search the world wide web for protein consumption recommendations, you'll find the current standard recommendation of 0.8 grams of protein per kilogram of body weight for all Americans, which is equivalent to saying everyone should wear the same shoe size.  This recommendation equals 45.6 grams for a 125lb person or 72.8 grams for a 200lb person. Granted it has taken us a number of decades to reach this .8 threshold, many are still not able to reach it.  Unbeknownst to the average person, the recommendation of .8 grams has been shown through various studies to be ineffective at helping older populations to maintain or build muscle mass. And as we also know, people across the world are different.....extremely different. So this one size fits all approach tends to leave many, woefully undernourished when it comes to meeting their specific protein intake requirements.  

The goal in protein consumption is to consume enough protein to overcome the negative effects of muscle degradation which is caused naturally through the aging process and through physical activity.    Achieving this goal, means that people will need to take different paths depending on their particular circumstances. 

 As the graph below shows, protein consumption needs vary by age, gender, and other statuses. 

Credit: Abbott

Before we go into greater detail regarding protein consumption requirements, there are some important facts that you should know. 

• First and foremost, amino acids are extremely important to every cell in the body. Your body uses amino acids to build and repair tissues; to make enzymes, hormones, and other chemicals.  Amino acids are the building blocks for bones, muscles, cartilage, skin, and blood.  
• Protein deficiency may cause stunted growth, muscle/joint pain, anemia, bone density issues, reduced muscle mass, fatigue, brain fog, hair thinning or hair loss, or swollen or puffy skin (edema). 
• When compared to carbohydrates and triglycerides (fat), proteins have the highest turnover rate. This means that protein breaks down and is created at a faster rate than other macronutrient. Protein turnover is the balance between protein breakdown and protein creation (synthesis).  Always remember these simple rules; When protein creation is greater than protein breakdown, than an anabolic state exists creating more muscle tissue.  When protein breakdown is greater than protein creation, than a catabolic state exists and no muscle tissue is created and existing muscle tissue deteriorates.
• On a small scale, proteins can serve as an energy source, when converted into fat or glucose.
• The human body cannot store proteins, like it stores fat and carbohydrates.
• The human body cannot create (synthesize) all 20 amino acids used to build proteins; meaning essential amino acids must be consumed.  
• When there is an amino acid deficiency, muscle tissue is broken down to get amino acids to build protein.
• Skeletal muscles are the major repository of amino acids, followed by the liver. 
• Amino Acids are the building blocks for proteins; they are not synonymous.
• Strenuous exercise increases protein breakdown and decreases protein synthesis (creation of new protein).  Recovery period acts in an opposite manner.  
• Older Adults benefit postprandial (after a meal) more from a fast protein such as Whey Isolate and younger individuals have greater protein retention from a slow protein like Casein.
• Plant based proteins undergo greater splanchinic extraction (retention of dietary amino acids by the gut and liver for their own needs) and subsequent urea synthesis than animal derived proteins. 
• Animal based, not plant based, proteins contain other biologically active compounds such as creatine, Vitamin B12, taurine, carnosine, conjugated linoleic acid (CLA), carnitine, iron, and cobalamin which favorably influence muscle physiology. 
• Animal based proteins have higher Protein Digestibility Corrected Amino Acid (PDCAA) Score or Digestibility Indispensable Amino Acid (DIAA) Score, and Biological Value, than plant based proteins.
• Plant based proteins are incomplete (except Soy) and do not contain all of the essential amino acids (e.g. lysine, methionine, cystein, threonine). 

 The chart below represents additional protein consumption recommendations from various credible sources.  

 Now let's take a look at a typical daily meal. 

 *Biological Value is a measure of the proportion of absorbed protein which becomes incorporated into the proteins of the organism's body.  

 As the table shows, a person can still be deficient in meeting their protein needs, even though the food choices used in our example are healthy choices.   In this case, overall protein intake for a 125lb person was a plus 14.9 grams and a negative 27.8 grams for a 200lb person. Also understand the protein needs increase based on activity level and age.  The biological value for each protein type quantifies how much protein is incorporated into the proteins of the organism's body.  For example, the BV for chicken breast is 79, which means that 79% (34 grams) of the 43 grams is expected to be incorporated into the proteins of that person's body; ultimately lowering the total protein used by the body.  So for you fast food consumers, you should certainly beware since most fast food operations use lower quality, processed foodstuffs to make their meals, making it even harder to reach your daily macro and micro nutrient requirements.  

So what can you do to meet your protein intake requirement?

Well, one can always eat more food to increase protein intake.  However, who has time these days to make or consume additional meals throughout the week?  The first thing one should consider is to select higher quality protein sources.  Using higher quality protein sources helps to ensure more amino acids are available for the body to use.  Just remember biological value....  A second recommendation is to fill the protein gap, by consuming a high quality protein replacement meal or powder.  As shown in the chart below, Whey Protein Isolate has the highest biological value of all protein sources.  Additionally, a Whey Protein Isolate has lower lactose content making it easily digestible.  Just make sure the Isolate is not mixed with a lower quality protein such as a concentrate.  A Whey concentrate protein and Casein protein have higher amounts of lactose, making them harder to digest for many people and are lower on the protein quality scale.   

Krok-Schoen, J. L., Price, A. A., Luo, M., Kelly, O. J., & Taylor, C. A. (2019, February 19). Low Dietary Protein Intakes and Associated Dietary Patterns and Functional Limitations in an Aging Population: A NHANES Analysis. Retrieved May 7, 2019, from https://link.springer.com/article/10.1007/s12603-019-1174-1

Osterweil, N. (n.d.). The Benefits of Protein. Retrieved May 7, 2019, from https://www.webmd.com/men/features/benefits-protein#1

Protein Deficiency: Signs, Symptoms, and Recommendations. (2019, January 23). Retrieved May 9, 2019, from https://www.humann.com/nutrition/protein-deficiency/

Roitman, J. L. (2006). ACSMs certification review. Philadelphia, Pa.: Lippincott Williams & Wilkins.