Part 1 of The Protein Chronicles introduced the vast array of proteins we build and rebuild on a consistent basis.
It also introduced the twenty one, nitrogen-containing building blocks that the body uses to create each different protein - the amino acids.
Part 2 now turns it’s attention to muscle, a tissue vital for health, strength, and longevity.
Your Muscle Is Your Might
I am becoming more and more of a muscle-centric nutritionist and that’s not because I work with a lot of athletes. It’s because everybody’s health, strength, body fat loss and longevity is determined, to a large extent, by the quality and quantity of muscle tissue.
Consider the following;
1. Muscle is the primary tissue that oxidises (burns) fat as fuel.
If you want to decrease your body fat or maintain your body fat levels, then you need to protect your muscle tissue at all costs.
It really doesn’t help that a significant portion of weight loss that occurs with many calorie restricted diets comes from muscle.
I would also apply the same thinking to any athlete who puts in significant miles with too low or no carbohydrate.
It’s true that at a lower heart rate you can utilise body fat effectively as fuel, but body fat can never account for 100% of needed calories. At best it can account for 50-55%. At no carbohydrate intake, the other 50 or 45% would come from glycogen, the storage form of carbohydrate in the muscles. This is finite and once it runs out you simply start breaking down and converting muscle tissue to glucose to make up the energy shortfall.
This is not a good strategy. It’s akin to building a beautiful timber frame home and then using it for firewood.
2. Muscle is the primary site of glucose disposal.
Something has to happen to all the energy contained within the bonds of the carbohydrate you eat.
Regardless of the source, all carbohydrate is eventually broken down to glucose.
Your muscles and other tissues, utilise what it needs, but if no energy is required, that energy has to be stored.
Excess glucose first gets converted to glycogen, a finite store of about 1200-1800 calories that resides in your muscles. The bigger the muscle mass, the bigger the storage capacity.
But once that finite store is full, excess glucose gets shunted to the infinite store - body fat.
If your muscle mass decreases, you literally decrease your capacity to oxidise or burn fat, dispose of glucose, and you limit your glycogen storage capacity. The result - more glucose ends up as fat.
Ever wonder why you put on more body fat after a severe calorie restricted diet?
Of course, the reverse is also true. If you build muscle you build fat oxidation and glucose disposal capability plus you increase your capacity to store excess glucose as glycogen.
3. Muscle tissue has the highest proportion of mitochondria, those bright little energy producing organelles.
More muscle equals more energy producing ability. All you need to do is provide the fuel.
Of note, muscles adapt to training by building even more mitochondria (as long as you supply enough amino acids of course!).
4. Muscle maintains strength, mobility and function.
And while the above is a short little sentence, if you’re 80 years old, it’s everything!
How Do We Lose Muscle?
How many of the below boxes can you tick?
Lack of calories or a pattern of calorie restricted diets over many years
Lack of movement, especially as we age
Lack of protein intake
Menopause and decreasing hormone levels
Prolonged endurance exercise with inadequate fuelling levels
Injury or surgery leading to a lack of weight bearing activity
But the great news is, it’s also pretty easy to maintain and build muscle too!
How Much Protein Do We Need?
Even though I want you to think in terms of amino acid intake, recommended dietary allowances (RDA) are still given as grams of protein. For most adults, the RDA is 0.8g protein per kg of body weight.
This is not informative. That 0.8g/kg depends on context - what are your specific needs? Do you want to build muscle? Are you an athlete or an endurance athlete? Are you post-surgery or suffering from an injury? Are you in a fat loss phase? Menopausal?
Bear in mind that that the RDA is the minimal amount to prevent deficiency. This is vastly different from proactively protecting and building muscle mass.
Most researchers would agree that 1.2-1.8g per kg is more in line with protect and build. And please calculate that using your ideal body weight. If you are 110kg and would like to be more in the range of 90kg, then use 90kg as your reference.
Protein Needs As We Age
As we age we need to think about protein and amino acid intake differently.
Children absorb proteins effectively in whatever dose or format it comes in (allergies and intolerances aside). The important thing for children is the total daily amount, which can range from 14.5g at 1-3 years old to 28.5g at 10 years old.
As long as they get that, they will synthesis new tissue. They will grow.
As we age we have to start thinking both in terms of daily total and the amount per feed or dose.
At 25 years old, an amount of 15g protein at any one feed can stimulate tissue synthesis and growth, measured by the blood biomarker commonly known as muscle protein synthesis (MPS).
But after the age of 25, when we are considered biological adults, research tells us that we need a bigger amount of protein at any one feed to positively affect muscle protein synthesis.
That bigger amount is between 30 to 45g.
It's important to note that our capacity to synthesis new protein doesn’t decrease as we age, we just need to hit 30-45 grams per dose to stimulate it.
That’s key information.
Growing Muscle By Stimulating Muscle Protein Synthesis (MPS)
Let’s go back to leucine, one of the nine essential amino acids.
At a certain blood level this specific amino acid signals the machinery of muscle protein synthesis to get in gear. And I use the word signal purposefully here.
An adult needs to ingest around 2.3-2.6g of leucine to provide an effective signal. That amount is nearly always present within 30g protein.
Lightbulb moment! This is why that 30g dose of protein is so effective.
Once the blood level of leucine rises, it remains high for about 2 hours before returning to baseline. In that time the biomarker for muscle protein synthesis increases. This is what is known as an anabolic (build) response.
Even when leucine returns to baseline, the machinery of muscle protein synthesis stays active. Another 30g of protein (2.3-2.6g leucine) will signal the biomarkers of synthesis to rise again.
Leucine is contained in all animal foods. It’s particularly high in whey protein isolate. Smaller amounts are contained in plant sources such as oats, lentils, peas, soya beans, peanuts and pumpkin seeds. But I bet if you look at a plant based (soya or pea) protein isolate you’d see leucine in good amounts.
Part 3, the last of The Protein Chronicles addresses how we need to eat to get the most out of this amazing macronutrient.
If you don’t want to read all 3 parts of this blog series but want to get the most out of your protein - do this.
Make sure you ingest a minimum of 30g of protein in your first meal of the day.
Concentrate the rest of your protein at meal times versus spreading it out in smaller amounts.
Ingest around 1.2-1.8 grams protein per kilogram per day (all dependant on lean body mass, life circumstance and activity level) but remember to get it in 30g amounts.
If you are a vegetarian or vegan, think about introducing a soya/pea or plant based protein isolate. You are going to need more total protein because bioavailability from plant sources is simply less.
If nutrition is an area of your health that you find confusing and you’d like some clarity - reach out - or make sure you hit that FOLLOW button.
I work with everybody.
Every. Body.
jill@teamjoebarr.com