Dietary Principles
Principles, practices and guidelines for a holistically health supporting diet
Protein Principles
Protein Principles for Optimal Health
There is debate over whether a high protein or low protein intake is most supportive of health. Advocacy for a low protein intake is typically based on concern that a higher protein intake will upregulate metabolic processes that accelerate aging and age related disease risk. There is some evidence for this albeit mainly in mice.
Set against this, advocacy for a higher protein intake is usually based on the certainty that higher protein intakes support increased muscle, and muscle is a highly current and long term health supporting organ, providing functionality (being able to *do* stuff), reducing the risk of injury, and acting as an endocrine organ, secreting myokines with multiple health supporting effects.
If you choose to prefer the higher protein approach, the key principles to apply are:
1. Total Protein Intake
There is a fair consensus that for actively exercise individuals, protein intakes of 1.4 to 2.0 grams per kilo bodyweight (0.63 to 0.9 grams per lb) is safe and supports improved recovery and adaptation to exercise
2. Protein Dosing Per Meal
There is a demonstrated increase in muscle protein synthesis from meals that contain a minimum of 25 grams of protein and 3-4 grams of the leucine amino acid, making this an ideal target to apply per meal.
You may read that there is a "maximum" amount of protein one can benefit form within a single meal, but initial research that led to this understanding was using extremely rapidly digesting whey protein. Slower digesting proteins and mixed meals will change that picture completely.
3. Protein Intake Timing
Since there is no effective longer term 'pool' of amino acids for the body to use, unlike stores of fat and glucose, and since there will be an upper limit to how much protein can be effectively utilised from a single meal, it is ideal to take in protein rich meals 3 or more times daily.
For example, if aiming for 100 total grams of protein daily, 3 meals each containing 30+ grams.
4. Protein Quality
The key quality features are how well the amino acid profile of a protein sources matches what is typically needed, and how much of the protein in a food will be digested and absorbed.
Great wholefood sources include eggs, muscle meat, organ meat, fish, bivalves (such as mussels), cottage cheese and some dairy.
It is possible to obtain sufficient protein for all the above from plant-based sources, with some caveats. One is that the amino acid composition is often less ideal in plant based sources compared to the better animal based sources such as whey, egg, fish and lean meats. One can address this by combining different sources and eating more total protein.
Secondly, wholefood plant based protein is usually bound up in a complex fibrous matrix that may render some of the protein undigested as it passes through the small intestine.
Last, plant based protein sources often contain more carbohydrate than protein. Plant-based protein powders can work around this issue.
Top plant based options include fermented soy products (tempeh, some tofu, natto) and lupin or lupini beans, which have a far higher protein content than all others. Mycoprotein, from fungi, is also a great option, for example, from the Quorn brand (available in the UK)
5. Protein Powders
Protein powders are not essential for most, but do provide simple and quickly available protein which can be consumed alone or mixed into a meal, shake or soup.
Protein powders will often not provide the added nutritional qualities - micronutrients and phytonutrients - that wholefood sources do, so they are ideally used as part of, but not the only and not the main protein source.
In addition to the popular whey and vegan blends suitable for shakes and smoothies, one can use savoury proteins such as beef, pea and pumpkin seed for adding to soups and dips and as the "flour" base for high protein bread.
> Link goes to the International Society of Sports nutrition Position on Protein and Exercise