So we’ve looked at protein before, as a macronutrient. We know it’s extremely important for our bodies, and it gets a lot of attention, especially among body builders, strength trainers and crossfit gurus. But what exactly does this macronutrient do for you? Today, we’ll dive into this building block in some detail and see if we can’t unravel how it works, why it’s so important to your body, and just how much you should be consuming.
What is protein?
To quote myself from the macronutrients article referenced above:
Proteins are an important part of a balanced diet, they help with growth, preserving lean muscle mass and ensuring a healthy immune system that functions properly. Proteins are found in meats, poultry, fish, cheese, milk and to a lesser amount in fruits and vegetables. When eaten, protein is broken down into amino acids (the building blocks of proteins). There are two types of amino acids – essential amino acids that must be supplied by our diets and non-essential amino acids, which our bodies can produce themselves. Below is a list of the essential amino acids and a general overview of what they do for your body (warning – we’re about to get a little chemistry-ish!):
• histidine – maintains the myelin sheaths which surround and insulate nerves. Histidine is required for the production of histamine, and is often used in the treatment of anemia, allergies, rheumatoid arthritis and other inflammatory reactions.
• isoleucine – is important in hemoglobin synthesis and regulation of blood sugar and energy levels.
• leucine – stimulates protein synthesis and assists with muscle building.
• lysine – plays an important role in the production of enzymes and hormones, as well as the formation of bones and muscles.
• methionine – one of the major roles of methionine in the body is that it can be used to produce other important molecules critical for normal cell function. It is involved in the production of cysteine which is used to build proteins in the body.
• phenylalanine – plays a key role in the biosynthesis of other amino acids and is important in the structure and function of many proteins and enzymes. Phenylalanine is converted to tyrosine, used in the biosynthesis of dopamine and norepinephrine neurotransmitters.
• threonine – this amino acid is vital in the folding and function of proteins. Protein folding is the process by which a protein structure assumes its functional shape. By coiling and folding into a specific three-dimensional shape they are able to perform their biological function.
• tryptophan – our bodies convert it to 5-HTP (5-hyrdoxytryptophan), and then to serotonin, melatonin, and vitamin B6 (nicotinamide). Serotonin is a hormone that transmits signals between nerve cells.
• valine – is important for smooth nervous system and cognitive functioning.
The best sources for these essential amino acids come from proteins found in animal sources because animal sources contain ALL essential amino acids, while proteins from most plant sources do not. That’s not to say that you should shy away from a vegetarian diet if that’s your thing, (Chia and Hemp seeds for example do contain ALL essential amino acids) but realize that it’s a lot easier to get the ESSENTIAL aminos from a diet that includes animal sources. If you choose to be a vegetarian on your fitness journey, that’s great, but do your homework and make sure you’re taking care of your body’s needs.
So this tells us a LOT about what protein is – basically a collection of amino acids, but how does your body use protein to synthesize muscle? Is eating protein alone enough to build muscle?
In a word, no. Protein requires a one-two punch to build bigger, stronger muscle. When we exercise, we create micro-tears in the muscles we use, some exercise modes create more tears than others (resistance training for example). The body then uses the amino acids that it breaks down from the protein we consume to surround and fill in the tear, making the muscle bigger and stronger. Because of the need for these tears, and the repair process, protein levels alone aren’t enough to make yourself stronger.
To be honest, I was a little let down by the simplicity of this explanation. While I certainly didn’t expect elevated consumption levels of protein to create muscle, I thought there would be a lot more to the formation of muscle than just a repair job to the existing muscle. However, our bodies prefer simplicity over complexity, so it makes sense that there wouldn’t be a huge biological magic to the process.
Are there any dangers to protein?
Generally speaking, no. Protein is a macronutrient after all, so it’s a building block of – well – you. So over consumption typically reflects as weight gain (excess protein not used by the body is usually stored as fat).
However, there is some mixed data online that suggest that over consumption could “impose a metabolic burden on the bones, kidneys and liver” and could also “be associated with increased risk for coronary heart disease due to intakes of saturated fat and cholesterol or even cancer” (per The National Center for Biotechnology Information). The reason I say “mixed data” is that it’s unclear whether the results reported are due to elevated protein levels or the sources of the protein (eg red meat or processed / fast foods). I’ve linked the referenced article in the resources below if you’d like to learn more about this.
So how much protein should you be consuming per day?
The U.S. Recommended Daily Allowance for protein is 0.8 grams per kilogram of body weight per day (convert your pounds to kilograms by multiplying your weight by 0.453592 – or use this handy converter 🙂 ) It appears that this formula for protein consumption is the same for men and women. To further compound any confusion you may have about protein, Harvard Health suggests that “Athletes who have large muscles and work out hard may need 20% more”
So for me – a 185 pound human being – that would be:
83.9 kg x .8 or 67 grams of protein per day.
If you’re presuming that I’m a muscular athlete (debatable!) then, according to Harvard, I should consume an additional 13.4 grams of protein (20% x 67 + 67) for a maximum total of:
80.4 grams of protein per day.
There are plenty of online calculators out there that will help you determine your protein intake, but I’m not sure I’m a fan. I tried one on calculator.net that took into account my age, weight, gender and how frequently I work out, and received 3 results claiming between 63 grams and 222 grams daily! That’s a WILD swing in results. I think I’ll stick with the US RDA and on day’s I’m feeling really crazy, I’ll shoot for the Harvard version. I’d rather play it safe and face a possibility of “less gains” than pay it fast and loose with 222 grams per day and maybe be facing colon cancer someday. No thanks. This experiment in health and fitness is about health for me, but if you want to go crazy and eat nothing but protein to hit tat high mark, by all means, here’s the link to the calculator so you can check out your own recommendation.
So what are some good natural sources for protein?
When looking for protein, lean (low fat) proteins are the ones you want to go for. Some good healthy sources include:
- Egg Whites
- Skinless, White Meat Poultry (Chicken or turkey breast)
- White Fish
- Lean Beef
- Pork Loin
- Plain Greek Yogurt (No sugar – you want sweet? Add fresh fruit)
- Beans or lentils
- Low-Fat Cottage Cheese
- Low-Fat Milk
- Peanut Butter (In moderation, this can be a calorie hog)
What about supplements?
Look, 60-80 grams of protein is a lot to consume, so it makes sense to add in supplements like protein shakes / powders if you’re having trouble hitting those numbers.
Protein powders come in 3 common forms – concentrates, isolates and hydrolysates. The most pure form being the hydrolysates, with the other 2 containing more impurities in the form of fats and carbs (so still not bad!)
The most common form of protein, and from my research, the most favored, is whey protein. Whey protein is synthesized from milk, so it does contain lactose, which can be a problem for some people, however, it is digested quickly and is rich in BCAA’s, including leucine, which plays a major role in muscle growth and recovery. In fact, a study shows that whey protein increases muscle protein synthesis 31% more than soy protein and 132% more than casein protein.
There are numerous other types of protein powders, including caesin, egg, pea, soy and wheat, but as mentioned, whey seems to be the best option based on my research.
One thing I did find while researching proteins relates to pea powder – a choice popular among vegetarians and vegans. Some organic pea proteins have been found to contain high levels of glyphosate. Glyphosate is an endocrine disruptor that has been linked to liver disease, birth defects and reproductive problems. It may also kill beneficial gut bacteria and damage the DNA in human embryonic, placental and umbilical cord cells. For those of you using this protein, I’d be curious to hear what you know about this in the comments, and if this is news to you, please consider a safer alternative like soy or wheat.
If you’re looking for a recommendation, I’d use Bodylogix Natural Grass-Fed Whey Protein Powder, NSF Certified, Vanilla Bean. It’s NSF certified and tastes great.
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Harvard Health – Good nutrition: Should guidelines differ for men and women?