Are you trying to build a more muscular body? I bet you didn’t realize that not only does too much protein not build more muscle; it can cause health issues such as osteoporosis, constipation or diarrhea. Don’t miss understand this statement, adequate protein is critical for a healthy body and some people need more than others.
Many nutrients and compounds are needed to build muscles in our bodies. For the sake of article length, I will limit this discussion to protein intake.
Lets explore the metabolism of protein required for building muscles in the human body!
There seems to be a lot of confusion regarding the amount of protein needed to build muscle mass. What builds muscle? True muscle growth comes from two different biological effects of weight bearing exercise;
- hyperplasia which is the increase in the number of muscle cells
- hypertrophy which is the growth in size of the actual cell.
Both are the result of the stress load on muscle fibers from exercise or strenuous work, which initiates the uptake of amino acids in the form of proteins. Excess amino acids (building blocks used to make proteins) are burned as fuel or metabolized into fat. Your body never likes to use more than 10% of its energy needs from protein. Only so much muscle protein synthesis (MPS) can occur. You can’t force feed muscle cells. The first 3 hours after a workout is the time when the majority of MPS will take place.
It is really amazing how many articles I have read from bodybuilding sources that say a person should consume between 2 to 4 grams of protein for every kg of body weight, or that a person should consume 1 to 1 ½ grams of protein per pound of body weight. That would mean a 200-pound man would need to consume between 200 grams and 363 grams of protein daily. The DRI for protein intake under normal bodily demand would be .8 grams of protein for each kg of body weight. To figure your body weight in kilograms, divide your weight in pounds by 2.2, that number is your weight converted from pounds to kilograms. For the obese the protein intake would be .8 grams for every kg of muscle mass. For an athlete with heavy demands on muscle performance such as a body builder or an Olympic athlete the intake would be 1.6 to 1.7 grams of protein per kg of body weight meaning that same 200 pound man would consume 145 grams of protein at the high-end. An endurance athlete such as those running marathons, iron man events and triathlons requires less because they are not placing as much stress on the major muscle groups. Their needs can be met in most cases with no more than 1.2 to 1.4 grams of protein per kg of body weight. The average person who works out in the gym and is very active hiking and playing organized sports does not need this level of protein intake.
Consuming high quality complex carbohydrates is equally important because it keeps the body from burning those ingested proteins for fuel allowing the body to use the proteins for MPS.
Protein synthesis is most effective when the body is fed adequate complex carbohydrates. This allows the body to use the protein for building muscles, hormones, enzymes and other protein compounds. Without enough complex carbohydrate the body is forced to burn the protein for energy instead. The body prefers carbohydrates as its major source of energy. So make sure at least 50% of your calories are from complex carbohydrates. Weight lifting is an anaerobic action, which requires glucose (sugar) for fuel. Sugar is a form of carbohydrate.
Protein is used for many functions not only muscle growth. Protein is required to build and repair muscle cells, hormones, blood cells, enzymes, antibodies and antigens.
The excess intake of protein can cause serious health consequences. The consumption of a high protein diet typically means the person is also consuming excess saturated fats and cholesterol and less fiber. Excess fats and cholesterol increase LDL and total cholesterol levels increasing the risk for heart disease. Taking excess protein in supplements can also cause digestive issues such as constipation, diarrhea and cramping. Protein metabolism requires a lot of water. Thus excess protein intake may cause dehydration as well.
In addition, animal proteins, particularly from dairy, promote calcium loss and are a promote of osteoporosis.
“Women consuming greater amounts of calcium from dairy foods had significantly increased risks of hip fractures, while no increase in fracture risk was observed for the same levels of calcium from nondairy sources.”
12-year Harvard study of 78,000 women American Journal of Public Health 1997;87
“Consumption of dairy products, particularly at age 20 years, were associated with an increased risk of hip fractures…metabolism of dietary protein causes increased urinary excretion of calcium.”
American Journal of Epidemiology 1994;139
A high protein diet typically results in a lowered consumption of fiber, which is critical for colon health. There is no fiber in meat. As noted in Clinical Nutrition a Functional Approach pg. 27, adequate fiber intake is cardio-protective, glucose regulating and cancer protective. Fiber in a bottle is never an equal to fiber from vegetative foods. A recent Japanese study published in the Asian Pacific Journal of Cancer Prevention, 2002 concluded that as dietary animal protein, fats and oils increase, the incidence of colo-rectal cancer increases. However, colorectal cancer rates decrease as dietary plant protein increases.
As protein replaces vegetative foods the diet could be lacking vital macro and micronutrients such as vitamins, minerals, fiber and phytonutrients that are contained in plant foods and not found in animal foods. A lack of nutrients over time can lead to health issues such as impaired immune function, digestive disorders, fatigue, hormonal imbalances and insulin resistance.
The metabolic synthesis of protein causes different acids to be formed. To neutralize the acids the body must release calcium from bone to bring the body’s pH back into balance. Over time a high intake of proteins can cause osteoporosis. However, certain plant foods that also contain proteins such as grains, nuts and seeds and legumes contain higher levels of potassium which help decrease urinary calcium loss.
For people with decreased kidney function excess protein intake can lead to further impairment of kidney function and even promote kidney disease.
The very high intake of proteins as recommend by many body building and sports health publications and body building organizations is misleading and can cause bodily harm through the dissemination of incorrect dietary information regarding protein intake.
Excess protein, particularly from animals can increase the risk of bone loss, heart disease, obesity, impaired kidney function, cancers and even type II diabetes. The absence of carbohydrate to provide for adequate glucose or glycogen synthesis to fuel the Krebs cycle, ETC and neurological functions will cause the body to use the protein for fuel thus reducing the amount of protein that can be used for bodily functions that require dietary protein. When protein intake replaces complex carbohydrates the diet can be denied important phytonutrients that promote health and may even lower the risk of certain diseases. Furthermore, protein does not increase muscle mass or strength. The stress load on muscles triggers the body to use amino acids provided by dietary proteins to form specific proteins for building and repairing muscle tissues, MPS.
Research published in The Journal Physiology 2001 states “Overfeeding protein does not increase the size of the lean body mass, and amino acids supplied in excess of the requirements of protein synthesis are simply oxidized (Motil et al. 1981; Price et al. 1994) and their carbon skeletons used for fuel or stored as fat. The rise in plasma urea observed in this study supports this interpretation.”
Some of these people will suffer from serious illness and disease from excessive protein intake. Sadly the illness or disease may be caused by their false belief that a high consumption of dietary protein is superior at building muscle mass and muscle strength compared to current DRI recommendations for protein intake.
Wally Bishop C.N.C., I.N.H.C.
Integrative Nutrition Health Coach
The contents of this blog is not and should not be considered medical advice. This blog is for informational purposes only. Always consult with your doctor before making any dietary or lifestyle changes. Never quit taking prescription medications unless advised to do so by your doctor.