THE MACRONUTRIENTS: PROTEIN
For decades, protein has been the macronutrient of choice for fitness pros, bodybuilders, and gym rats. Many of us have consumed, or at least heard about, protein shakes, whey isolate, BCAAs, and other supplements. And as of late, much of the current nutrition debates center around low protein versus high protein diets. But let’s backup to the beginning and start from a foundation of science–the first step to understanding that most often gets ignored. So what the heck is protein?
What is protein?
Protein is one of the three macromolecules that humans receive from food—the other two are fat and carbohydrate. Through the digestive process, all three of these “macros” are broken down into smaller and smaller units that provide energy and nutrients for our cells. Proteins, specifically, are made-up of long chains of amino acids that fold into complex shapes, and sometimes even bundle into groups together.
What are amino acids?
Amino acids are small, organic compounds that contain carbon, hydrogen, an amine group, a carboxylic acid group, and a side chain that we call the “R” group. The “R” group is what distinguishes each amino acid from the others.
There are twenty amino acids in total. Nine of those are considered essential, which means they must be consumed to be available, and the remaining eleven can be synthesized by your body.
Like Legos, amino acids can be pulled apart and re-configured in seemingly endless ways to form thousands of different proteins. These proteins are used as a scaffolding for muscle, hair, skin and nails, enzymes, bone, many hormones, and other cell signaling molecules. When it comes to proteins, the structure of the shape dictates its function. So thousands of proteins spanning every inch of your body all have different 3-D shapes that indicate what that protein is used for. Every enzyme for every specific chemical reaction has a distinct sequence of amino acids, which dictates how it folds into its complete shape, which then dictates what its capable of doing. Some proteins contain several dozen amino acids while other contain tens of thousands. A protein called titin is the third most abundant protein in muscle, aside from myosin and actin, and it tends to be approximately 27,000-33,000 amino acids long. We need a lot of amino acids to make all of our proteins!
Amino acids don’t get stored the way fat and carbohydrate can be. Instead, they’re usually being recycled, used as intermediates in other metabolic pathways, kept in the amino acid pool for muscle use, or excreted.
Where can you get amino acids?
Foods labeled as “complete proteins” contain all nine of the essential amino acids necessary in the human diet. Typically, the most complete proteins will come from animal sources such as seafood, poultry, eggs, wild game, beef, and dairy. Additional plant-based complete proteins include quinoa, buckwheat, algae, soybeans.
For many vegetarians or vegans, a diverse set of incomplete proteins must be combined throughout the course of a day in order to receive all the necessary amino acids. These sources can include beans, whole grains, seitan, nuts, and seeds.
How much protein do you need?
First, let’s start with how much protein is currently recommended. In the United States, the Recommended Daily Allowance is 0.8 g per kilogram of bodyweight. For a 150 pound person, that’s about 55 grams of protein. For a 200 pound person, that’s about 72 grams of protein. However, this calculation has two caveats: (1) The RDA’s are most likely going to change, as that dosage has been found to be inadequate to prevent sarcopenia in aging adults, and (2) this dose is the bare minimum to keep a human alive. There is a big difference between not dying and thriving.
Let’s focus on thriving.
According to the The International Society of Sports Nutrition, a sufficient amount of overall daily protein intake is more in the range of 1.4–2.0 g of protein per kg of bodyweight per day for most people to build or maintain muscle mass when combined with exercise. For a 150-pound person, that’s approximately 95-136 grams of protein per day, or 126-180 grams of protein daily for a 200-pound person.
Further large-scale clinical studies have shown that eating up to 4.4 g/kg (2 g/lb) body weight didn’t cause any short-term health problems and supported the construction of more lean mass when combined with resistance training.
Protein Quality
Housed within the adequate intake of proteins is hopefully adequate intakes of each amino acid. Not all amino acids are used in the same way, and each is important. For example, the essential amino acid leucine is also one of the branched-chain amino acids. Leucine is the “start” signal that begins the process of muscle protein synthesis. Because of this, we judge protein content and dosages often in regard to essential amino acid, and particularly leucine, availability. A protein dose of 20–40 g of protein (10–12 g of EAAs, 1–3 g of leucine) seems to be the “sweet spot” for stimulating the growth of new muscle tissue.
The Protein Myth
One of the most common statements surrounding protein consumption is that it will damage your kidneys. However, the genesis for this concept stems from the fact that people with poorly functioning kidneys may do better on a lower protein diet because it lessens the need for glomerular filtration and creatinine clearance–both of which are metabolic events required for protein processing. But those are people with a pre-existing injury/illness. That’s very different than the idea that protein caused that damage. This is an important distinction and essential for releasing this myth.
“Published reviews on this topic consistently report that an increased intake of protein by competitive athletes and active individuals provides no indication of hepato-renal harm or damage. This is supported by a recent commentary that referenced recent reports from the World Health Organization where they indicated a lack of evidence linking a high protein diet to renal disease. Likewise, the panel charged with establishing reference nutrient values for Australia and New Zealand also stated there was no published evidence that elevated intakes of protein exerted any negative impact on kidney function in athletes or in general” (JISSN).
Meta-analyses–studies that systematically assess the results of previous research–continue to find that protein does not damage the kidneys. And because we see such benefits from high-protein diets on preventing muscle loss, decreasing appetite, muscle building, and weight loss, it’s important to acknowledge this.
Protein for Weight Loss
Protein is a dieter’s best friend. First, eating protein tends to make people feel fuller at mealtimes, which makes them eat less, and helps them stay feeling full for longer. This effect on our hunger and satiety hormones makes our lives easier when we’re trying to lose some weight. Second, when dieting, people often lose lean mass as well as fat mass because the body is in an energy deficit. If the diet is high in protein, it can promote muscle sparing, particularly when combined with resistance training. Because there are plenty of available amino acids, our own muscles can be spared from degradation. That way, once the weight is lost we can save some of our metabolic rate from dropping even lower because muscle is energetically expensive. Lastly, protein has the highest thermogenic cost to digest, meaning it costs more calories to digest than other foods. For these reasons, protein helps us shed fat mass, save lean mass, and burn a few extra calories.
Protein for Muscle Gain
The most recent research shows that the fastest digesting proteins that contain high proportions of essential amino acids and adequate leucine are most effective in stimulating muscle protein synthesis. For that reason, consuming protein doses periodically throughout the day, and particularly around workouts, is essential for muscle growth.
After workouts, there is an anabolic window where muscle cells may be more sensitive to protein uptake. For years, bodybuilders have famously used their nutrition to jump into this window with shakes and large meals post-workout. While research has shown that there does appear to be an anabolic window, it likely is several hours long and not as brief as it was once throught to be. For most people, a complete protein meal after a workout is perfectly adequate. However, to take the programming up a notch, a fast-digesting animal protein supplement like whey protein powder should be consumed post-workout because it is ideal at helping your body to make more muscle as compared to a plant-based protein like soy.
Major Takeaways
Overall, we can look at some fantastic research to make sense of the wonderful macronutrient that is protein.
We can see that:
- It supplies vitally important amino acids that give us the building blocks for our whole body
- It provides the nourishment and supplies needed for muscle construction
- It makes us feel fuller for longer
- It burns the most calories during digestion
- It can promote healthy and lean-mass sparing weight loss
- It can optimize performance by promoting lean mass development
- It’s safe to eat
If you want to build muscle, lose some weight, and feel satisfied at meals, investigating your protein intake is an important piece of your nutrition puzzle. Check-in with yourself to make sure that you’re consuming complete proteins at mealtimes or throughout the day, that you’re getting adequate leucine–especially after workouts–and that you’re consuming a complete protein after a workout.
Sources
Brandle E, Sieberth HG, Hautmann RE. Effect of chronic dietary protein intake on the renal function in healthy subjects. Eur J Clin Nutr. 1996;50:734–40.
Devries MC, Phillips SM. Supplemental protein in support of muscle mass and health: advantage whey. J Food Sci. 2015 Mar;80 Suppl 1:A8-A15.
THE MACRONUTRIENTS: PROTEIN
For decades, protein has been the macronutrient of choice for fitness pros, bodybuilders, and gym rats. Many of us have consumed, or at least heard about, protein shakes, whey isolate, BCAAs, and other supplements. And as of late, much of the current nutrition debates center around low protein versus high protein diets. But let’s backup to the beginning and start from a foundation of science–the first step to understanding that most often gets ignored. So what the heck is protein?
What is protein?
Protein is one of the three macromolecules that humans receive from food—the other two are fat and carbohydrate. Through the digestive process, all three of these “macros” are broken down into smaller and smaller units that provide energy and nutrients for our cells. Proteins, specifically, are made-up of long chains of amino acids that fold into complex shapes, and sometimes even bundle into groups together.
What are amino acids?
Amino acids are small, organic compounds that contain carbon, hydrogen, an amine group, a carboxylic acid group, and a side chain that we call the “R” group. The “R” group is what distinguishes each amino acid from the others.
There are twenty amino acids in total. Nine of those are considered essential, which means they must be consumed to be available, and the remaining eleven can be synthesized by your body.
Like Legos, amino acids can be pulled apart and re-configured in seemingly endless ways to form thousands of different proteins. These proteins are used as a scaffolding for muscle, hair, skin and nails, enzymes, bone, many hormones, and other cell signaling molecules. When it comes to proteins, the structure of the shape dictates its function. So thousands of proteins spanning every inch of your body all have different 3-D shapes that indicate what that protein is used for. Every enzyme for every specific chemical reaction has a distinct sequence of amino acids, which dictates how it folds into its complete shape, which then dictates what its capable of doing. Some proteins contain several dozen amino acids while other contain tens of thousands. A protein called titin is the third most abundant protein in muscle, aside from myosin and actin, and it tends to be approximately 27,000-33,000 amino acids long. We need a lot of amino acids to make all of our proteins!
Amino acids don’t get stored the way fat and carbohydrate can be. Instead, they’re usually being recycled, used as intermediates in other metabolic pathways, kept in the amino acid pool for muscle use, or excreted.
Where can you get amino acids?
Foods labeled as “complete proteins” contain all nine of the essential amino acids necessary in the human diet. Typically, the most complete proteins will come from animal sources such as seafood, poultry, eggs, wild game, beef, and dairy. Additional plant-based complete proteins include quinoa, buckwheat, algae, soybeans.
For many vegetarians or vegans, a diverse set of incomplete proteins must be combined throughout the course of a day in order to receive all the necessary amino acids. These sources can include beans, whole grains, seitan, nuts, and seeds.
How much protein do you need?
First, let’s start with how much protein is currently recommended. In the United States, the Recommended Daily Allowance is 0.8 g per kilogram of bodyweight. For a 150 pound person, that’s about 55 grams of protein. For a 200 pound person, that’s about 72 grams of protein. However, this calculation has two caveats: (1) The RDA’s are most likely going to change, as that dosage has been found to be inadequate to prevent sarcopenia in aging adults, and (2) this dose is the bare minimum to keep a human alive. There is a big difference between not dying and thriving.
Let’s focus on thriving.
According to the The International Society of Sports Nutrition, a sufficient amount of overall daily protein intake is more in the range of 1.4–2.0 g of protein per kg of bodyweight per day for most people to build or maintain muscle mass when combined with exercise. For a 150-pound person, that’s approximately 95-136 grams of protein per day, or 126-180 grams of protein daily for a 200-pound person.
Further large-scale clinical studies have shown that eating up to 4.4 g/kg (2 g/lb) body weight didn’t cause any short-term health problems and supported the construction of more lean mass when combined with resistance training.
Protein Quality
Housed within the adequate intake of proteins is hopefully adequate intakes of each amino acid. Not all amino acids are used in the same way, and each is important. For example, the essential amino acid leucine is also one of the branched-chain amino acids. Leucine is the “start” signal that begins the process of muscle protein synthesis. Because of this, we judge protein content and dosages often in regard to essential amino acid, and particularly leucine, availability. A protein dose of 20–40 g of protein (10–12 g of EAAs, 1–3 g of leucine) seems to be the “sweet spot” for stimulating the growth of new muscle tissue.
The Protein Myth
One of the most common statements surrounding protein consumption is that it will damage your kidneys. However, the genesis for this concept stems from the fact that people with poorly functioning kidneys may do better on a lower protein diet because it lessens the need for glomerular filtration and creatinine clearance–both of which are metabolic events required for protein processing. But those are people with a pre-existing injury/illness. That’s very different than the idea that protein caused that damage. This is an important distinction and essential for releasing this myth.
“Published reviews on this topic consistently report that an increased intake of protein by competitive athletes and active individuals provides no indication of hepato-renal harm or damage. This is supported by a recent commentary that referenced recent reports from the World Health Organization where they indicated a lack of evidence linking a high protein diet to renal disease. Likewise, the panel charged with establishing reference nutrient values for Australia and New Zealand also stated there was no published evidence that elevated intakes of protein exerted any negative impact on kidney function in athletes or in general” (JISSN).
Meta-analyses–studies that systematically assess the results of previous research–continue to find that protein does not damage the kidneys. And because we see such benefits from high-protein diets on preventing muscle loss, decreasing appetite, muscle building, and weight loss, it’s important to acknowledge this.
Protein for Weight Loss
Protein is a dieter’s best friend. First, eating protein tends to make people feel fuller at mealtimes, which makes them eat less, and helps them stay feeling full for longer. This effect on our hunger and satiety hormones makes our lives easier when we’re trying to lose some weight. Second, when dieting, people often lose lean mass as well as fat mass because the body is in an energy deficit. If the diet is high in protein, it can promote muscle sparing, particularly when combined with resistance training. Because there are plenty of available amino acids, our own muscles can be spared from degradation. That way, once the weight is lost we can save some of our metabolic rate from dropping even lower because muscle is energetically expensive. Lastly, protein has the highest thermogenic cost to digest, meaning it costs more calories to digest than other foods. For these reasons, protein helps us shed fat mass, save lean mass, and burn a few extra calories.
Protein for Muscle Gain
The most recent research shows that the fastest digesting proteins that contain high proportions of essential amino acids and adequate leucine are most effective in stimulating muscle protein synthesis. For that reason, consuming protein doses periodically throughout the day, and particularly around workouts, is essential for muscle growth.
After workouts, there is an anabolic window where muscle cells may be more sensitive to protein uptake. For years, bodybuilders have famously used their nutrition to jump into this window with shakes and large meals post-workout. While research has shown that there does appear to be an anabolic window, it likely is several hours long and not as brief as it was once throught to be. For most people, a complete protein meal after a workout is perfectly adequate. However, to take the programming up a notch, a fast-digesting animal protein supplement like whey protein powder should be consumed post-workout because it is ideal at helping your body to make more muscle as compared to a plant-based protein like soy.
Major Takeaways
Overall, we can look at some fantastic research to make sense of the wonderful macronutrient that is protein.
We can see that:
- It supplies vitally important amino acids that give us the building blocks for our whole body
- It provides the nourishment and supplies needed for muscle construction
- It makes us feel fuller for longer
- It burns the most calories during digestion
- It can promote healthy and lean-mass sparing weight loss
- It can optimize performance by promoting lean mass development
- It’s safe to eat
If you want to build muscle, lose some weight, and feel satisfied at meals, investigating your protein intake is an important piece of your nutrition puzzle. Check-in with yourself to make sure that you’re consuming complete proteins at mealtimes or throughout the day, that you’re getting adequate leucine–especially after workouts–and that you’re consuming a complete protein after a workout.
Sources
Brandle E, Sieberth HG, Hautmann RE. Effect of chronic dietary protein intake on the renal function in healthy subjects. Eur J Clin Nutr. 1996;50:734–40.
Devries MC, Phillips SM. Supplemental protein in support of muscle mass and health: advantage whey. J Food Sci. 2015 Mar;80 Suppl 1:A8-A15.