Many of us pay close attention to the fats and carbohydrates that we eat, yet very little consideration is given to how much protein we take in through our diet.
The importance of protein in health is flagrantly understated.
While most people think they are eating enough protein, the recent scientific evidence indicates that we should eat more – much more than the dietary guidelines would have you believe. This is especially true if you want to stay fit and healthy, you would like to perform better, are trying to lose weight, if you are suffering from chronic pain and/or illness, or if you are simply getting older.
If you have been a patient of mine, you have likely been subjected to numerous rants about the importance of protein. This article is a much more structured (and referenced) version of that!
While the purpose of this article is to help you to understand the importance of protein in your diet, the underlying theme is addressing the importance of muscle when it comes to general health and healthspan.
What is Protein?
Protein is just one of 3 macronutrients that you take in through your diet. Even though all 3 macronutrients can be used by your body for energy, carbohydrates are the major player here while fats are mainly used as energy storage.
Protein forms a large portion of the functional and structural parts of our body.
Hormones and enzymes are proteins that carry out bodily functions. Protein also forms our cell walls and components, it acts as scaffolding that holds our cells together to form tissues and organs. It can be found in abundance throughout our whole body, including in our blood, bone, skin, and brain.
A large portion of our body’s protein is stored in muscle.
How Eating Protein Influences Your Muscle
When you eat protein, your gut breaks it down to the basic protein molecules called Amino Acids. The amino acids then get absorbed into the bloodstream and find their home in tissues that need them for building and repair.
Our muscle is actually the largest deposit site for these amino acids (protein) in our whole body. That is because our muscles serve a number of important functions, and they are constantly being broken down and rebuilt.
Even though protein is absolutely essential for thriving muscle (and other tissues), it is important to note that our bodies do not have a reservoir of protein to pull from when our muscles need it. The protein resources our muscles need on an hour by hour, day by day basis, must be delivered in real time through our meals when we eat protein.
And our muscles crave protein!
In fact, they need it for maintenance as well as growth. So much so that researchers have shown that the simple act of eating a protein-rich meal produces a temporary yet significant burst of muscle anabolism (growth) following the meal.
This simply indicates that when our body senses a large-enough intake of protein in a meal, it goes to work. It builds muscle.
The bottom line, and the purpose of me writing this article, is that ingestion of protein in our diet can have a direct influence on the amount and quality of the muscle we keep. Keep this statement in mind while you read through this article.
But… before I can convince you to eat more protein, let me tell you why muscle is so important!
The Importance of Muscle
Our muscles are in a constant flux between muscle breakdown (loss) and muscle synthesis (gain). Depending on which way the balance tilts, determines whether we are gaining muscle, or losing it. The goal is to gain and avoid losing muscle.
Having an abundance of quality muscle is important for a number of mechanical and metabolic reasons.
It is easy to understand that muscle is important to our overall function and ability to do work.
What may be less commonly understood is how maintaining optimal muscle quality and size is also directly linked to the health of our bones and joints, which plays a vital role in staving off chronic pain and illness. Maintenance of adequate muscle can also help us to avoid the fragility associated with old age, and preserve our independence.
Muscle also plays a major role in energy metabolism. Simply put, the more muscle we have, the more energy we burn, even as we rest.
And since about 80% of the sugar we digest from our meals ends up in muscle, it plays a crucial role in keeping our blood sugar stable, avoiding spikes that lead to insulin insensitivity and over time, diabetes.
An individual that lacks muscle is at a much higher risk for a number of conditions that have their roots in metabolic dysfunction. This includes metabolic syndrome, obesity, cardiovascular disease, type 2 diabetes, and cancer. Consequently, this individual is also more likely to live a shorter life.
The take-home point here is that if you are interested in living a long and healthy life, avoiding chronic pain and illness, and maximizing your healthspan and independence, then you should be working towards optimizing the quality and quantity of your muscle. Eating enough protein is essential to achieving this.
Unfortunately, there are many scenarios that favour muscle breakdown over muscle synthesis. Let’s dig deeper into these.
Conditions That Favour Muscle Loss
Hanging on to muscle may prove to be harder than most people think. In fact, it’s a constant uphill battle to hang on to our lean mass.
Here are the top three reasons why people lose muscle:
- They aren’t active enough
- Their diet sucks
- They are getting older
When it comes to most of our body’s tissues, the “use it or lose it” principle applies. This is particularly true for muscle.
Just like calcium is leached out of our bones at a higher rate when we don’t regularly stress our bones through weight-bearing activity, the same occurs with protein from our muscles, but at a much higher rate.
Muscle is one of the most adaptive tissues in our whole body. It is changing constantly as a result of the demands that we make of it. If the demands go away, so does muscle.
A recent experiment showed that just 5 days of immobility resulted in a loss of about 3.5% of leg muscle mass, which represents about 150 gram loss of lean muscle tissue. This loss in muscle size coincided with a 9% loss in muscle strength. Did I mention that this happened in just 5 days?!
Blown away yet?
Another study showed that a 2-week reduction (75%) in steps taken throughout the day was enough to produce a 4% loss of muscle in the legs. The decreased activity was also enough to essentially throw the study subjects into a pre-diabetic state, complete with a modest increase in whole body inflammation.
Remember how just eating enough protein can lead to an anabolic effect, where the body temporarily increases the rate of muscle synthesis?
It appears that even a short bout of low activity is enough to make our body less sensitive to protein-rich meals, limiting this anabolic response. Following the two weeks of reduced activity, the same study found a 26% reduction in this anabolic effect in its subjects (more on this later).
Clearly, even a short period of reduced activity can wreak havoc. These consequences get even more grim with longer sedentary periods, like after surgery, or when recovering from an illness like cancer.
The reality is, everyone has been through a sedentary period in their lives, whether voluntarily or involuntarily.
If you have ever been laid out for days or weeks by an illness, you have lost a significant amount of muscle, and have suffered other related consequences, whether you noticed them or not. And, I bet it took you a lot longer (and more effort), to return to normal! Anyone who’s had training derailed by illness or injury can attest to this.
Here is another dose of reality – you don’t actually need to be ill or completely sedentary to lose muscle.
Do you know of someone who doesn’t perform regular exercise? They are most likely losing muscle.
To maintain your body’s muscle, you need to move. Specifically, you need to move against resistance.
Resistance exercise is THE most potent stimulus for muscle synthesis and it is absolutely essential if you want to grow or maintain your muscle. This is especially important as you age (see below). A little bit goes a long way, and more is always better.
Combining a regular resistance exercise regimen with optimal protein intake is the recipe for success if the goal is to maintain, and even gain quality muscle.
LOW PROTEIN IN THE DIET
As mentioned above, protein is an integral part of all tissues of the body. These tissues, especially muscle, are in a CONSTANT state of remodeling. And, unlike carbs and fats, our body does not have a means to store amino acids (protein). It can make some of them, but not all of them.
Using our muscles (or exercising) naturally damages our muscles on a microscopic level, stimulating our body to break the muscle down and rebuild it. Without adequate delivery of protein from our diet, the muscle breakdown will exceed the muscle synthesis, tipping the scale towards net muscle loss.
We simply cannot rebuild or gain muscle if our diet is low on protein.
Scientific evidence shows that the people who regularly eat more protein benefit by having more lean muscle mass and strength. This is especially notable in seniors, and older individuals who eat little protein have been shown to have higher rates of disability compared to those who consume protein-rich meals multiple times per day.
Once again, the above evidence is true because our bodies rely so heavily on us supplying it with protein at meal-time. Just ingesting protein will cause a temporary “anabolic” effect where muscle synthesis is significantly increased.
If you don’t eat enough protein, you are missing a crucial window of opportunity to increase muscle synthesis multiple times per day. Eat enough, and you increase the likelihood that the balance between muscle breakdown and muscle synthesis leans towards growth!
Unfortunately, this anabolic effect of simply eating protein is greatly affected by your age.
Let’s face it, getting older is tough on the body. Aging is marked by a steady decline in many bodily functions, including those in muscles.
Sarcopenia is a term used to define the progressive age-related decline in muscle mass and function (strength). This phenomenon is stealthy and has real health-related consequences. This process can start earlier than you might think, and progress at an alarming rate.
It can be seen in some individuals as early as their 30s, where the average loss of muscle mass is about 0.8% per year. By the time you are over the age of 60, you may be losing up to 3% of muscle mass per year due to sarcopenia.
Since sarcopenia changes the composition of your muscles over time, the declines in muscle strength tend to be much more drastic than the declines in muscle mass. This decline in muscle function can have dire consequences on the health of your bones and joints, your ability to function, and as a result, your independence as you age.
As mentioned previously, the loss of lean muscle tissue also affects your ability to burn energy and regulate sugar which can have dramatic consequences on your risk of developing chronic systemic diseases.
Our two best assets in the fight against sarcopenia are performing regular resistance exercise (by far the best asset), and eating enough quality protein in our diet.
I want to emphasize the qualifier “ENOUGH” here. It is important we eat enough protein for our age as the typical anabolic response we get when we eat protein in our diet gets blunted as we get older.
Researchers call this “anabolic resistance”. And to put things in perspective, if the goal is to maximally stimulate muscle synthesis after ingesting a meal rich in protein, it would require that an older adult (65+yo) almost twice as much protein when compared to a younger adult (18-37yo) (more on this below).
Compounding the problem, due to the aging digestive system, our body simply becomes less efficient at using dietary protein as we age, once again emphasizing the importance of increasing our protein intake as we age.
Unfortunately, rather than increasing protein consumption to compensate for these biological challenges of aging, researchers say that as we age, our dietary protein intake tends to decline progressively.
Evidently, life makes it easy to lose muscle. But let’s now switch the conversation to conditions that favour muscle growth.
Conditions That Favour Muscle Gain
Indeed, it is much easier to lose muscle then to maintain it.
Besides injecting yourself with anabolic steroids, the most potent stimuli for nurturing muscle growth are:
- Performing resistance exercise and;
- Eating enough quality protein.
Although getting enough resistance exercise and eating adequate amounts of protein does take effort, it is a small price to pay when you factor in the fact that maintaining quality muscle is so important for retaining pain-free function, for the prevention of chronic diseases and for staying independent as we age.
PERFORM REGULAR RESISTANCE EXERCISE
I guess all those grunting gym-rats can’t be wrong… right?
If you want to optimize your muscle and the benefits that come with that, you cannot do it with just regular aerobic exercise… or yoga… or walking… etc.
The most effective way of maintaining muscle is by regularly forcing it to work against resistance!
Resistance exercise not only triggers our body to immediately begin to synthesize muscle, it actually puts the exercised muscle in a prolonged anabolic state, where the increased muscle synthesis continues for several DAYS. And, if you regularly consume protein in your diet, the muscle synthesis outweighs the muscle breakdown.
However, I fear that too many people overthink resistance exercise.
In a recent article, I explained how resistance exercise does not need to be complicated in order for it to be effective. It does not have to involve heavy lifting, elaborate training regimens, or expensive equipment.
In fact, exercises that utilize your own body weight, but are performed until fatigue (i.e.: less weight but more repetitions) are enough to grow muscle, and may actually produce similar strength gains.
So keep it simple, but be consistent! Watch the video below to see an example of an easy at home workout.
Oh… and eat your protein.
EATING ENOUGH PROTEIN
Finally we have arrived at the very reason for me writing this article! As you can guess by this point, I believe most people should eat more protein. Give me a few more paragraphs to convince you.
Do you think you are eating enough protein?
While that could very well be true, it is important to define what “enough” really means, and whether you could benefit further by eating more.
The current dietary guidelines suggest that the Recommended Daily Allowance (RDA) for adult protein intake is 0.8 grams of protein per kilogram of bodyweight per day (ie.: 0.8g/kg/d). These RDA values are designed to meet the basic needs of the healthy adult population.
While 0.8g/kg/d is enough protein to avoid malnutrition, a very good argument can be made for eating more. Significantly more for that matter. Afterall, is avoiding malnutrition the goal? Or is the goal to optimize?
Assuming that gaining muscle is the ultimate goal (and it should be), adapting strategies to maximize muscle gain should be used.
Studies have shown that the anabolic effect that occurs in muscles after a protein containing meal (temporary stimulating a spike in muscle synthesis) is increased with progressively higher quantities of protein in the meal.
This means that eating 20 grams of protein in a meal is better at stimulating more muscle synthesis then eating 10 grams of protein.
In a healthy “average” individual in their mid-20s, eating approximately 20 grams of protein, or more accurately 0.24 grams per kilogram of bodyweight (ie: 0.24g/kg) in a single MEAL, seems to take full advantage of the anabolic effect of eating protein, and will stimulate muscle synthesis to the maximum in most cases.
So, if this person eats 3 meals per day, they can get away with following the RDA (0.8g/kg/day) and still capitalize on the maximum anabolic effect of protein ingestion as 3 meals of 20g IS EQUAL TO a total of 0.8g/kg/day in an average (75kg) individual. Keep in mind that this recommendation is based on averages.
What happens if this fictitious person eats more protein?
Since the anabolic effect is maximized, eating more protein will likely result in the body using it for energy, or disposing of it.
In contrast to the younger population, healthy OLDER adults tend to require a greater dose of protein at mealtime to garish the same anabolic effect.
One pivotal study showed that older individuals are less sensitive to protein intake, and in order to see the same maximal levels of meal-related muscle synthesis, participants over the age of 65 had to ingest, on average, 0.40g/kg of body weight in a single meal. This equates to 30g for a 75kg person. The younger counterparts were able to attain those same results with an average protein meal of 0.24g/kg of body weight, OR approximately 20g (consistent with the information above).
These numbers may seem shocking, but they don’t even tell the full story.
The authors point out that the recommendations to maximally stimulate muscle synthesis with ingested protein may be even higher in some people as:
- The subjects used in this study were healthy participants (young and old). People who are less healthy may be less sensitive to the anabolic effects of eating protein and therefore may need to eat more (see “Getting Older” above).
- The ingested protein used to test what dose is best at maximally stimulating muscle synthesis was high quality, animal-based and highly digestible protein (whey protein). People getting their protein from other sources (like plants) may need to eat more to maximally benefit from the anabolic response of eating protein.
- The recommendations quoted are AVERAGES, and that for some individuals, to stimulate maximum muscle synthesis may take up to 0.60g/kg if they are older, and up to 0.40g/kg if they are younger.
So, tell me…
Do You Still Think You Are Eating Enough Protein?
In summary – muscle is important! It allows us to keep moving, decreases our risk of chronic illness, and helps us maintain independence and quality of life.
We now know that for a number of reasons, it is very easy to lose muscle. Fortunately for us, we have two effective strategies to both build and maintain muscle.
- Perform resistance exercise regularly. Period. This is the most potent tool that we have to build muscle, and prevent muscle loss.
- Consume adequate protein. Simply ingesting protein is a potent stimulus for muscle synthesis. However, if you are working out, this will help you make the most of the time and energy that you are spending exercising – don’t let your effort go to waste!
In a future article, I will provide more info on the protein intake recommendations, and give you the tools to apply your newfound knowledge practically – with real life strategies to utilize in your daily life to help you to maximize your ability to gain and maintain muscle.
And YES, there will be a discussion about plant vs. animal protein!
In the meantime, if you have any protein-related questions, HIT ME UP!