Recently I have been noticing lots of info out there about too much protein being a bad thing, and I wanted to sort through it all so I have it straight. Personally, I have noticed that as my training load has decreased over the past few 3-4 years, my protein cravings have decreased as well. I think my days of finishing off a 20 oz steak are over (yes, it really happened, and quite frequently). As with many things, I think if you listen to your body it will give you a good idea of what it needs. Putting that all aside, here is my breakdown on what you should know about protein.
First of all, what is protein? It is a macronutrient that provides the building blocks for all living tissue in the body. In humans, there are 20 amino acids that are created to build proteins(and many more that don’t form proteins). Of these amino acids 10 are considered non-essential because our bodies are capable of producing them. Another 9 of these are considered essential since our bodies cannot produce them itself; we must obtain them from food. There is also one that is deemed semi-essential since it needs to be consumed only under certain circumstances. It is important to note that the essential amino acids are not more important than the non-essential amino acids; the terms are simply differentiating that you must obtain the essentials from your diet.
So that brings us to the next question, what are amino acids? Amino acids are organic compounds which contain at least one amino group (-NH2) and a carboxy (-COOH) group. They are the basis of all life processes and essential for all metabolic activities.
You’ve also probably heard of something called BCAAs. Three of these essential amino acids, leucine, isoleucine and valine are considered branched-chained amino acids (BCAA) because they have a branched molecular structure. They differ from other amino acids because they’re broken down primarily in muscle, instead of in the liver. Research has shown that BCAAs can help improve exercise performance.
Ok, so now that we have the basics sorted out how much protein do we need on a daily basis? And how does this differ when adding in physical activity? What are the risks of too much or too little protein?
Many experts recommend consuming 0.7 - 1.0 grams of protein per pound of lean body mass. To calculate this specifically you will need to know your body fat percentage. If you don’t know it, you can make an approximate calculation.
Suggested Protein Intake Example Calculation:
For a 130 lb person with 25% body fat:
130 - (.25 X130) = 97.5 lbs lean body mass
At .7g per lb lean body mass: 97.5 X .7 = 68.25g protein
At 1.0 g per lb lean body mass: 97.5 X 1.0 = 97.5g protein
So for this person the range for daily protein intake would be 68 - 98 grams, depending on age and activity level. Our protein needs increase as we age, and athletes also require more protein than a sedentary people. If your goal is to build muscle you will want to stay near the top of your intake range. If you’re looking to maintain your current body composition then your protein intake will be somewhere in the middle. If your goal is too lose muscle mass you will want to stick to the bottom (or possibly just below) of your calculated range. However, we are each an experiment of one, so it may take some trial and error to determine what the right protein intake is for you. Some athletes will require much more than 1g protein per pound of lean body mass to build and/or maintain muscle mass. But even for athletes it’s important to match protein intake with activity level, because there are risks associated with protein intake that’s too high.
What are these risks of too much protein consumption? Here is a list of a few of them.
1. Extra protein gets converted to glucose. Your body can’t store large amounts of protein so it converts excess protein to glucose (via gluconeogenesis) and if you don’t need the extra glucose it is converted into fat.
2. Consuming excess protein stimulates mTOR (mammalian target of rapamycin). mTOR is a nutrient signaling pathway that plays an important role in the aging process and in cancer cell growth. When mTor is stimulated it promotes growth, of both normal and abnormal cells. It also limits the destruction of damaged cells. BCAAs, leucine, in particular, will activate mTOR. You need this pathway activated to build muscle; but you want to be cautious with taking in more than you need.
3. Consuming too much protein can stress the kidneys. Your body must remove more nitrogen waste products from your blood, which stresses your kidneys. This can result in chronic dehydration.
4. Long term excess protein consumption can accelerate oxidation, glycation, and leptin and insulin resistance. Basically this means accelerating cellular functions therefore accelerating the aging process.
What are the risks of too little protein consumption? Here is a list of a few of them.
1. Extended low protein intake can slow metabolism, leading to lethargy, fatigue and weight gain.
2. If the foods you eat don’t provide enough amino acids, your body breaks down protein rich tissues (your muscles) to access them. This muscle wasting is called sarcopenia.
3. Low protein intake may impair your immune system, leaving you susceptible to a greater number and/or more severe infections.
Now that you have an idea of how much protein you need, here is my breakdown on protein supplements:
In general, protein quality is determined by the amount and types of amino acids that it contains; animal proteins are more complete than plant based proteins. Bioavailability is the percentage of absorbed protein that can actually be used by your body. This does not explain the amount of protein, but how much of the available protein can be synthesized by your body.
Bioavailability of Common Protein Supplements - Descending Order:
Animal Based Proteins:
All Whey: Contains all essential among acids, enhances immune system, high in leucine (promotes muscle growth and recovery after endurance and resistance training)
Whey Isolate- Fast absorbing, lactose free, higher protein content than concentrate
Whey Concentrate- low lactose level
Whey Hydrolysates- partially broken down by exposing the protein to heat, acid or enzymes that break apart the bonds linking amino acids (basically “pre-digested”), absorbs even faster than isolates or concentrates, can taste bitter
Denatured Whey- has been processed at a high temperature
Undenatured Whey- has been processed in such a way that harmful organisms are destroyed, but the heat sensitive amino acids that make it bioactive are not harmed
Egg White: Contain all essential amino acids, second only to whey protein as a source of leucine
Casein: Contain all essential amino acids, absorbs more slowly than whey providing more steady release of amino acids
Plant Based Proteins:
Rice: Contains all of the essential amino acids, but is too low in lysine to be considered a complete protein
Soy: Can have heart health and hormone balancing benefits, but can also be highly allergic. Soy can help protect against cancer by filling estrogen receptor sites (which prevents more dangerous estrogens from doing so, reducing cancer risk)
Pea: Amino acid profile is similar to whey, but with lower bioavailability, popular with vegans
Hemp: Contains all essential amino acids, but with lower bioavailability than animal proteins
Side Note: Whey Protein vs Collagen?
I frequently get asked which is better, whey or collagen protein? The answer is they serve different purposes. Collagen supplies amino acids that are required by the body to build connective tissue and regulate cell growth. As we age our collagen making ability decreases, so supplementing with collagen becomes increasingly important. It supports skin, muscle, cartilage, ligaments, hair and helps stimulate bone growth. Collagen is also high in glycine, an anti-inflammatory amino acid, and low in cysteine. Whey protein is great for building lean muscle mass and losing fat, as it’s loaded with BCAAs. It also contains larger amounts of cysteine, which helps boost levels of glutathione (cellular antioxidant) but you need to use caution when having it in high doses consistently.
How much and what type of protein can be confusing, so I hope I clarified some of these questions! Including too much protein in your diet is a common mistake, especially for people who are transitioning to eating fewer carbs. When you’re cutting carbs from your diet you need to put an emphasis on adding healthy fats, otherwise it’s easy to fill the gap with unneeded protein. My take away for athletes - have your protein shake after training when you need to build and repair muscle; but skip the extra protein on your easier days. If you are in the habit of having a post workout shake, you can simply skip the protein and focus on the other ingredients like fruits, vegetables, green and red powders and other superfoods. I think that I have covered the basic run down to get people started here, but as I was writing this I realized how much more detail I'd like to cover! So, I decided to break into two parts - stay tuned for Protein Part 2!