Are you protein deficient?
INTRODUCTION
This information is mostly summarised from Peter Attia’s “the drive” podcast #224 with Professor Don Layman. Professor Layman’s work has helped to define the role of BCAA’s in skeletal muscle metabolism, and his research focuses on understanding the protein and amino acid requirements needed for adult health. In addition, Examine.com is referenced throughout for accurate scientific definitions and supporting research.
BRIEF SUMMARY ON AMINO ACIDS
We should approach “protein” intake like we do with vitamins. There are a number of different amino acids we need in the correct balance to build and repair cells in the body and synthesise and absorb nutrients, as there is a varied recommended intake of vitamins A,B,C,D, and so on.
There are 20 amino acids, of which 9 are Essential Amino Acids (EAAs), of which there are 3 Branch Chain Amino Acids (BCAAs). The 9 EAAs we must consume from our diet, the other 11 we can synthesise, so it is particularly important we get the right balance. The 3 BCAAs are considered the most anabolic (building muscle), with Leucine being fundamental to trigger mtor and muscle protein synthesis.
RDA & WHAT IS THE RIGHT AMOUNT
The body needs to make / replace approximately 300g of protein each day, with liver enzymes turning over every hour, muscle protein every 30 days, and collagen every 100 days. The body replaces every protein 4x year.
Of carbohydrates, fats and proteins, only protein contains nitrogen, and hence nitrogen balance is used as the basis for calculating RDA. This generally underestimates requirements as nitrogen is also present in others forms in foods, and we lose nitrogen from the body in the form of sweat, urine, stool etc. In addition these RDA’s are calculated for an average population, in an environment that is unlikely to match you as an individual.
A popular way to calculate protein requirement is as a % of your body weight. Generally somewhere around 0.8–1.6g / kg body weight is used for normal exercising adults. Professor Layman suggests the upper end of 1.6g / kg, which for a 70kg adult is 1.6 x 70 = 112g of protein each day. Note he does say if you can hit this target you can use a variety of sources, but if you are only getting 60–80g /day, you must ensure this is the perfect balance of amino acids, more to come.
PROTEIN SOURCES
However as previously mentioned, not all proteins are equal, they each have their own amino acid balance and bio availability. Generally, meat sources are in approximately the right amino acid ratio, as all animals are trying to accomplish the same task — build and repair cells in the body and synthesise and absorb nutrients. Hence a good whey isolate might be 95% bio available and have the correct balance.
Plants on the other hand need protein for a different purpose. They have fibres attached and use the amino acids for building stems, leaves, flowers etc. Hence plant proteins are generally only 60–70% bio available (with isolates being slightly higher), and in a different balance to what we need, with important amino acids like methionine being far too low.
For example, a particularly bad example for plant protein — if you were to read “protein quantity” on the side of a cereal box, for wheat bran, only 40% is bio available. Hence 5g of protein is actually only 2g once processed by the body, and in the wrong allocation of amino acids.
STRUCTURING YOUR PROTEIN INTAKE
The body cannot store amino acids like it can glucose or fats, and hence sometime after consuming your last amino acids, the body becomes catabolic, meaning the liver is breaking down skeletal muscle amino acids to provide to vital organs like the heart and brain. The longest fast of a 24 hour period is generally up to breakfast (it’s in the name), hence it’s most critical to get an adequate quantity of balanced amino acids.
After kicking off muscle protein synthesis, largely through the generation of mtor, the body stays in a protein anabolic state for some hours, and hence at lunchtime a smaller quantity of protein should keep your body anabolic.
Around 30–40g of amino acids from a balanced protein powder like whey concentrate or isolate, or meat source should be adequate to start muscle synthesis. Note this is 30–40g of amino acids, not of the supplement or food. If consuming plant protein, you are likely to need more, and might want to supplement with specific amino acids that are not present in high enough quantities. Professor Layman targets Leucine, Lysine and Methionine as the critical amino acids, of which Leucine appears to the most beneficial for muscle synthesis. 3–4g of leucine should be adequate.
Hence if you were to consume 90g of quality protein per day, a 40 / 10 / 40 split over breakfast / lunch / dinner would be potentially optimal.
EFFECTS OF AGE
As we age, our DNA degrades and produces less effective RNA which in turn builds lower quality amino acids. Hence as we become older, it becomes more difficult to heal, build muscle, repair cartilage etc. Therefore, even though our calorie consumption might come down with age, it’s important we consume more protein, and hence a higher % of overall calories, to make up for those inefficiencies. Amino acid supplements like collagen peptides would help target specific areas of regeneration too.
SUMMARY
Amino acids in the correct balance should be considered as a minimal requirement per day, not as a % of calories. The 9 EAAs we must consume from food sources, with different amino acid balances. RDA might not be the most effective way to estimate your requirements, especially when different food sources have different bio availability. Using your body weight x 1.6 will give as good estimate of your requirement if you are physically active. Breakfast is the most important, so front load your protein intake to kick off the production of mtor and muscle synthesis. Ensure you consume at least 30g of balanced amino acids, and 3–4g of leucine, to start the anabolic process. As we age, our body’s capability to produce amino acids degrades, and hence we have a higher requirement.
