Everyone knows that protein is important, but how many people actually know why this is the case? What is it about protein that makes it more desirable than fats and carbohydrates? People will say that it helps with fat loss, but how so? This article will attempt to give you an idea, not only of the benefits of protein but why protein is responsible for these benefits.
The Benefits of Protein
There are many benefits of protein, too numerous to mention in just one article, so we're only going to look at the most effective and interesting ones here.
Benefit #1. Protein increases your Metabolism
In 2004 Halton & Fu did a review of 15 studies that looked into the effects of protein on thermogenesis
<1>. They found that high protein diets increased thermogenesis compared to low protein diets, they also found
high protein to be more effective than high fat or high carbohydrate. Thermogenesis is the production of heat that leads to rising body temperature in humans. This leads to an increase in your metabolism.
How does it do this? There are three macronutrients: protein, fat, and carbohydrates. Out of the three, protein is the hardest macro for the body to break down. This means that the body will expend more effort to digest which results in increased thermogenesis. A study by Bray
et al (2015) found that hig h protein intake was correlated with increased energy expenditure
<2>.
Benefit #2. Increase Muscle Size and Strength
Exercise has a huge role on muscle size and strength (obviously) but without protein, this would not be the case
<3>. It is important to note that protein alone would not increase muscle size or strength, only when combined with exercise. Protein can help preserve muscle during a diet or prevent the loss of muscle when aging, but we'll cover this later.
How does it do this? When you exercise you perform many contractions of the muscle, this leads to muscle fibre damage. It might sound like a bad thing, but actually it is necessary if you want to increase your muscle size or strength. After a workout, your body needs to repair these damaged fibres, and make them stronger. It does this through a process known as muscle protein synthesis (MPS). This is where the body uses protein to repair and rebuild the fibres, for MPS to occur you need to have sufficient protein in your system. The more protein you take, the more you have available for MPS. Which is why Tarnopolsky
et al (1992) stated that an athlete requires double the daily protein of a sedentary person
<4>. There are other factors that affect MPS, sleep quality and duration, Testosterone and Growth Hormone release (either naturally or unnaturally acquired), and the quality of the workout. But none of this matters if your protein levels are insufficient.
Benefit #3. Improve Recovery from Exercise
After a heavy session, a complete lack of protein can cause your muscles to break down (known as catabolism). Increasing your protein intake will help your muscles recover from the exercise, it won't have much of an effect on DOMS (Delayed Onset Muscle Soreness - the reason you hate training) but it will help you.
How does it do this? Through the same process that we looked at earlier, muscle protein synthesis. Whilst MPS is crucial for building bigger and stronger muscles, it is also crucial for recovery.
Benefit #4. Protein can Improve Recovery from Injury
Studies have shown protein to be effective at helping people recover from traumatic injuries.
How does it do this? You're probably thinking, well if protein helps you recover from exercise then,
of course, it helps you recover from injury. Whilst it does work in the same way, there is a subtle difference. When recovering from exercise, protein is used to increase the benefits. Whereas when recovering from traumatic injuries (including burns) protein is used to prevent catabolism. This is because a traumatic injury will lead to a stress-response
<5>, which releases Cortisol.
Benefit #5. Protein can Strengthen Bones
One of the biggest problems for the elderly is the loss of bone mineral density, this seems to affect women more than men but everyone can be affected by it. Increasing protein intake has a great effect on bone maintenance
<6>.
How does it do this? It seems that it is not necessarily that a high protein diet is
good but rather the fact that a low protein diet is
bad for bone health. Lowered amounts of protein can lead to lower growth hormone levels which adversely affects bone mineral density. Also, a lack of protein can lead to less calcium being absorbed by the intestines
<7>. It should be noted that for a long time, there was a belief that high protein could also be responsible for loss of bone mineral density. This was thought to be because they claim that protein leads to loss of calcium due to its effect on blood acid level. This theory seems to be less popular now, but if you're worried about Osteoporosis then maintaining a medium protein diet (staying within the recommended level) whilst increasing dietary calcium is probably your best bet. However, if you're under 60 you probably shouldn't be worrying too much about this.
Benefit #6. Protein Can Help You When Dieting
Increasing your protein can help you diet in a number of ways, it can help with body composition, hunger, and prevent the loss of muscle tissue.
How does it do this? The Halton review we mentioned earlier
<1> looked at the effect of protein on satiety, this is the feeling of fullness you get after a meal. It found that eleven out of fourteen studies found that increasing the protein content of a meal led to "increased subjective ratings of satiety". Meaning that people who ate more protein felt fuller for longer, which does not automatically lead to fat loss but would lead to a lowered desire to snack between meals. The most important role that increased protein has on dieting is the protection of muscle tissue (or FFM as it is often known). This may not seem too interesting to some of you, but the last thing you want to do is lose muscle. What happens when you diet is that your body breaks down fat cells to make up for the lost calories, leading to loss of body fat. But what also happens is that the body breaks down muscle tissue as well, luckily you can reverse this by increasing your protein intake as the protein will help achieve muscle protein synthesis. This is doubly important if you are also exercising (which you should be if you want good results).
Conclusion So now you know the many benefits of protein intake, and more importantly you should now have an understanding of
how protein causes these benefits. Remember there are many ways that you can increase your protein intake, such as: Meat, fish, dairy, pulses, protein powders, and eggs. You should also start tracking your calories as this will give you a clearer idea of what your current protein intake is, and how much you need to increase it by. According to a study by Helms, Aragon, & Fitschen (2014) the ideal intake of protein for a regular person is 1.2-2.2g/kg bodyweight (so 120-220g for a 100kg person). Or 2.3-3.1 for somebody interested in pursuing natural bodybuilding
<8>.
