How does your body use protein?

Muscle growth requires a variety of amino acids, the building blocks of protein that your body uses to repair and strengthen muscle fibers.

Your body requires twenty-one amino acids. Your body can produce twelve of these, but must get the remaining nine from the food you eat. These nine amino acids that must be obtained from food are known as “essential” amino acids and they are: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.

Leucine is an especially important amino acid for muscle growth because it is considered the “switch” that stimulates protein synthesis.

Furthermore, leucine, isoleucine, and valine, are the branched-chain amino acids (BCAAs) that are popular supplements in the bodybuilding community because they make up about one-third of muscle protein. These are important amino acids that are easy to consume in a vegan diet with proper nutrition planning.

Bottom line: If you don’t eat enough essential amino acids (EAAs) for your activity level, your body will have trouble building and repairing muscle, and thus, muscle growth becomes impaired.

What’s the best source of protein?

Plant protein and animal protein have many similarities, but also many differences. In comparing the two, we must analyze three distinguishing variables that set them apart:

1. Different forms of protein digest at different speeds.
2. The body better utilizes some forms of protein than others.
3. Different forms of protein have different amounts of the EAAs our bodies need.

Overall, animal protein is more easily absorbed and assimilated into your body. Animal proteins contain more EAAs per gram and are more easily digested and absorbed.

This does not mean that plant protein is in any way inadequate or even puts vegan weightlifters and athletes at a disadvantage to their omnivorous counterparts. But as vegans, we do need to plan our protein consumption a bit more carefully.

And while they don’t have to worry about protein, the vast majority of omnivores need to plan their fiber, micronutrient, and phytonutrient consumption a little more carefully.

From a wholesome health and wellness perspective, plant protein is preferable because food is a package deal. Plant foods offer a copious array of health-promoting vitamins, minerals, antioxidants, and phytochemicals that animal foods do not. Furthermore, plant protein causes less aging enzyme activation, has less sulphur containing amino acids such as methionine, possesses lower acid-forming capacity in the kidneys, promotes less putrefaction in the colon, has no inflammatory response, and offers no adverse effect on the cancer promoting growth hormone IFG-1.

Here’s my take on the plant protein vs. animal protein debate: In the short-term, animal protein may help to more easily build muscle mass if you take a relaxed approach to your nutrition plan, but in the long term you’ll likely pay a price with your health. With careful planning, plant protein can build muscle just as easily as animal protein without jeopardizing long-term health. You generally need to eat a bit more plant protein than animal protein to get enough essential amino acids (EAAs) to achieve your muscle mass and strength goals. You can ingest multiple protein sources, like pea protein with rice protein, to provide a more balanced amino acid profile.

So what's so bad about eating animal products for protein?

Meat and animal products have high microbial loads, which release bacterial endotoxins. These bacterial endotoxins are responsible for causing inflammation and no amount of cooking gets rid of them.¹ Plant foods do not have high microbial loads and they also possess many anti-inflammatory properties making them ideal for workout recovery and health in general.

Animal products are also high in cholesterol (not just eggs!). Cholesterol itself can cause oxidative stress and inflammation.² This inflammation paralyzes our arteries and impairs their ability to dilate by 50% just hours after eating a high-fat meal.³ Meat is also high in sulfur-containing amino acids such as methionine, homocysteine, cysteine, and taurine. Methionine, in particular, has been shown to increase both inflammation and bodily acidity. ⁴ The highest source of dietary sulfur-containing amino acids such as methionine, is animal protein with fish being the highest and all other forms of animal protein following closely behind.

And if that wasn’t bad enough, these sulfur-containing amino acids raise our bodies’ acid loads, which we have to buffer with alkaline minerals including calcium which is leached out of our muscles to maintain our body’s slightly alkaline 7.4 pH. Beyond diminished athletic performance and inhibited muscle synthesis, the acidic environment produced by animal products promotes cancer and other diseases.⁵ Highly acidic animal-based diets cause calcium to be leached out of the muscles. Thankfully, the ingestion of potassium-rich alkaline foods such as fruit and vegetables relieves the mild metabolic acidosis that occurs with the ingestion of a typical American diet that is rich in protein.”⁶

The Need for “Plant Protein Combining” is a MYTH

Contrary to popular belief, plant proteins are not “incomplete” (meaning they are missing essential amino acids). The “incomplete protein” myth and the faulty research that spawned it was thoroughly debunked by MIT years ago. All protein found in grains, legumes, vegetables, and fruits is “complete.”

What is true, however, is that some forms of plant proteins are lower in certain amino acids than others, making certain sources better than others. For example, the protein found in peas and rice is superior to the protein found in hemp. Rice protein is a great choice. It has a high biological value – around 80 percent similar to beef – and tastes great in my opinion.

I like rice and pea protein sources because they’re similar to animal protein in terms of amino acid profile and protein digestibility.

While it is true that plant foods are lower in amino acids across the board than animal foods, you do not need to a fact that originated the myth of “protein combining.” With the exception of the animal protein gelatin, ALL proteins, plant and animal, contain all nine essential amino acids. In other words, pretty much all proteins are “complete” proteins. You do not need to combine food sources to get complete proteins. This is a myth that was widely popularized in Vogue in 1975. You don’t have to worry about “mixing” protein sources as a vegan. “High quality” versus “low quality” proteins are terms generally used to distinguish the relative proportions of the different essential amino acids found in certain foods. The more closely the proportion matches our own proteins, the higher its “quality.”

How much protein do we need?

People tend to get a lot more protein than they need.

First of all, it is impossible to not get enough protein unless you are not eating enough. In a study of about 13,000 people, only about 3% were not getting enough protein simply because they weren’t eating enough. Unless you plan on starving yourself, it is impossible not to get protein from your diet. As long as calorie intake is adequate, it is easy for vegetarians and vegans to meet recommendations for protein. Every plant on the planet contains protein!!

“An almost global consensus is that adults need no more than 0.8 to 0.9 grams of protein per kilogram per day to satisfy their protein needs.”¹ This equates to 0.36 to 0.41 grams of protein per pound of bodyweight per day. So, a 100 pound person needs about 39 grams of protein per day, a 150 pound person needs about 58 grams of protein per day, a 180 pound person needs about 70 grams of protein per day, and a 200 pound person needs about 77 grams of protein per day.

According to a 2013 study of 71,751 participants, those eating plant-based diets average about the same amount of protein intake (grams/day) as non-vegetarians.²

That's great, but how much protein do athletes, specifically bodybuilders, need?

Just because your favorite athlete eats a certain way does not mean it actually helped them achieve their accomplishments, it just means that they achieved their accomplishment in spite of their diet.

This study found no difference in whole body protein synthesis or indices of lean body mass in strength athletes consuming 0.64 grams versus 1.1 grams or more of protein per pound of body weight. The protein oxidation was much higher for the latter group indicating a nutrient overload.¹

This study performed on a group of novice bodybuilders found that there was no different in mass or strength gains between those consuming 0.61 grams and 1.19 grams of protein per pound of body weight. For maximum protein synthesis, the researchers recommended 0.75 grams per pound of bodyweight.²

This study on collegiate-level strength athletes found no differences in body composition, strength, or resting hormonal concentrations between those consuming 0.77 grams and 0.91 grams of protein per pound of body weight.³

The research indicates that the optimal level of protein intake is approximate 0.75 grams per pound of muscle mass.

My standard advice for protein intake when bulking is 0.9 grams of protein per pound of body weight per day. When cutting, you should consume around 1.1 grams of protein per pound of body weight per day.

These numbers are slightly higher than the recommended values in the cited studies because the digestibility of plant protein is about 10 to 30 percent lower than animal protein, depending on the food. To my knowledge, there are no studies analyzing the daily protein needs of athletes on a plant-based diet.