Let's talk protein: Why it's king of good health and body composition

Updated: Apr 6, 2020


Protein is not just a bodybuilder's food. It is essential to many aspects of our health.

If your priority is to improve your body composition (ie, you want to lose body fat, or you want to build muscle), it's particularly important to include sufficient protein in your diet. Even if you religiously adhere to a super strict, low calorie diet, you're probably not going to see the results you're after unless you eat an adequate amount of foods rich in protein.


A basic recap on protein


Proteins are chains of amino acids, used to build and maintain tissues in the body. Our bodies use proteins to make not just muscle, but also bone, skin, hair, and nails. Proteins also generate different enzymes, hormones, neurotransmitters and antibodies to enable normal bodily functions.


The first step is to stick to a consistent, adequate daily protein intake for the biggest bang for your buck.

Dietary protein is crucial because our body can't make all of the amino acids that it needs to function properly. After you eat a food rich in protein, your body digests the protein into its amino acid components. The amino acids then enter the blood stream, available for tissues to use.



How does protein affect body composition?


Protein supports our body to:

  1. Build muscle. Muscle isn't just for bodybuilders. If you want to look better, then you should care about your muscle mass. Muscle mass doesn't just make you strong - it also enhances your metabolism, improves insulin sensitivity and helps to stabilise blood glucose, all things that will make it easier to lose body fat and keep it off.

  2. Protect and maintain muscle while we lose fat. Research shows that people who lose weight on a diet higher in protein lose more weight from body fat than muscle tissue, especially if the person combines this diet with weights training [5]. Most people say that they want to lose 'weight', but really they want to lose fat and have a healthy shape (ie, to look fit rather than flabby.) It's muscle mass that makes you look good when you're lean!

  3. Maintain a higher daily resting metabolic rate, because our resting metabolic rate is largely based on our fat-free mass.

  4. Bump up daily energy expenditure, because protein takes more energy to digest than either carbohydrates or fat.

  5. Promote cell repair and recovery, which allows us to train harder and safer.

How much protein do I need to eat?

Current guidance recommends that adults consume just under 0.8 g / kg of protein a day [1]. So, for a 55 kg female, this would equate to 44 g of protein each day to meet the minimum requirements for basic human function.

However, this minimum amount may not be the optimal amount for you. It is based on the needs of a sedentary adult who isn't particularly active and doesn't hold a considerable amount of lean mass. It's meant to represent a level of intake necessary to replace muscle loss and avert protein deficiency [4].


Dietary protein is crucial because our body can't make all of the amino acids that it needs to function properly.

The minimum threshold may be appropriate to meet the needs of a person who doesn't train or exercise. But research suggests that it does not reflect the protein needs of a person who trains hard and wants to optimise their body composition. It's not enough to provide the amino acids your body needs to build and maintain lean tissue, repair training-induced muscle damage and offset the oxidation of amino acids while you exercise [2].

What does the research say?

There is research to suggest that people who are physically active and train regularly will benefit from a higher protein intake.

The International Society of Sport Nutrition takes the position that healthy, exercising people should consume 1.4 - 2.0 g / kg a day, based on the nature and intensity of their training. As a guide, they say that people who do endurance exercise should eat levels at the lower end of this range, people who exercise sometimes but not consistently tend to fall in the middle of the range, and people who do strength or high power training should eat levels at the upper end of this range [2]. Other studies support the general recommendation that people who do weights training need at least 1.6 g / kg a day of protein to maximise muscle protein synthesis [4]. There's also some evidence that novice lifters may need a little more protein at first (around 1.7 g / kg a day) to match the shift in their muscle protein synthetic rate, and that the protein requirements of seasoned lifters tends to decrease slightly (to around 1.4 g / kg a day) because their body becomes more efficient at protein utilisation [4].


The International Society of Sport Nutrition takes the position that healthy, exercising people should consume 1.4 - 2.0 g / kg a day, based on the nature and intensity of their training.

Ultimately, the numbers are a guide only. Everyone has their own individual protein needs, and can adjust up or down from this number to suit them. What's optimal for you will depend on a number of variables. Everyone is different. Some general factors to consider include:

  • How active you are day to day.

  • How hard and how often you train.

  • How much lean mass you have.

  • The other foods you eat (for example, I tend to eat slightly more protein when I eat less carbohydrates).

  • Whether you are dieting (for example, I bump up my protein a little if I'm in an energy deficit).

  • The quality of the protein source.

  • The timing of the protein intake.

  • How your efficiently your body uses protein (hormones like insulin come into play here).

  • Your genetics.


Does timing matter?

Personally, I believe that nutrient timing matters. But only if you have the basics right first.

Look at it this way. You could implement the 'perfect' nutrient timing system (if such a thing exists). But this will be pointless if you don't eat enough protein each day. If your number one priority is to build muscle, the total amount of protein you consume is the most important predictor of hypertrophy [4].


You may need to eat 'more' protein than you normally do to reach an optimal intake for you, but there's no benefit in more protein for the sake of it. In fact, too much protein could actually set you back.

Don't fixate on the details too early. The first step is to stick to a consistent, adequate daily protein intake for the biggest bang for your buck. Then, when you have your 'protein foundation' firmly in place and some familiarity with your body and its protein needs under your belt, you can test and measure different protein timing protocols to enhance your results. As you build experience, it becomes harder to put on muscle. Then it's time to use all the tools at your disposal. Protein timing is one of many tools that you can use to enhance your results.

Personally, I have a daily ball park protein figure that works for me. Most of the time, I will keep my protein around this amount, and adjust carbs and fats to suit my training phase. In numbers, I'd say this equates to about 90 per cent of my results. In other words, if I eat the right amount of protein for my body and its needs each day, this is pretty much all I need to do to in terms of protein to look and feel fantastic.



Remember - more is not necessarily better!

You may need to eat 'more' protein than you normally do to reach an optimal intake for you, but there's no benefit in more protein for the sake of it. In fact, too much protein could actually set you back. While total protein intake correlates to an increase in muscle mass, there is an upper limit [4].

If you want to lose fat ...


Keep in mind that protein is not a free-for-all when you're on a fat loss diet. Your body can convert the excess protein that it doesn't need into glucose for energy. That's not ideal if your aim is to carefully monitor your energy balance.

If you want to build muscle ...


Here's the kicker - even if your priority is to build muscle, too much protein is not your friend. An over supply of protein can cause problems in digestion, which means that your body won't be able to absorb the nutrients you consume as effectively. If you eat to fuel muscle gain, then you want to do all things in your power to support your body to put the foods you eat to work!

Sources

  1. National Health and Medical Research Council, Nutrient Reference Values for Australia and New Zealand including Recommended Dietary Intakes (2006).

  2. B Campbell et al, 'International Society of Sports Nutrition Position Stand - Protein and Exercise'. Journal of the International Society of Sports Nutrition (2007) 4:8.

  3. L Norton and G J Wilson, 'Optimal Protein Intake to Maximise Muscle Protein Synthesis'. Agro Food Industry hi-tech (2009) 20:2.

  4. B J Schoenfeld et al, 'The Effect of Protein Timing on Muscle Strength and Hypertrophy: A Meta-Analysis'. Journal of the International Society of Sports Nutrition (2013) 10:53.

  5. G Brinkworth and P Taylor, 'The CSIRO Low-Carab Diet' (2017).