protein quality

💪🏼 In the last post on protein, I mentioned that 20 g/protein should be consumed every 3-4h for optimal muscle protein synthesis (which is essential to avoid age-related sarcopenia), although ~40g may be required if the protein quality is compromised. So how can it be compromised?

 💪🏼 Protein quality is determined by the amino acid composition, their bioavailability and digestibility. 

 💪🏼 Animal protein is considered as a complete protein, which means that it entails all essential amino acids (EAA). In contrast, plant proteins generally lack 1 or more EAA, which means that a few food sources need to be combined to achieve a full EAA profile.

 💪🏼 Complete plant proteins include: buckwheat, quinoa, chia, soy & its derivative products (e.g. tofu), hemp, amaranth, spirulina, nutritional yeast, mycoprotein (quorn).

💪🏼 Plant protein combinations that make up a full EAA profile include:

1. Peanut butter & whole wheat toast

2. Hummus & pitta

3. Beans & rice

4. Lentils & rice

5. Lentil soup & whole wheat bread

6. Pasta & peas

7. Spinach salad & sunflower seeds

 💪🏼  The general tip on how to combine plant proteins to get a complete protein is to mix grains with pulses or nuts & seeds.

💪🏼 In terms of bioavailability, some plant proteins may be encapsulated, making them harder to digest. Broadly, 60-80% of plant proteins are available, while animal proteins are >90% available.

 💪🏼 Nevertheless, processing can increase the bioavailability of proteins, which means that more protein can be extracted by the body from chickpea flour than from whole chickpeas, for example. However, fibre is lost in exchange for more protein, which means that adding some extra vegetables to your meal may be a good idea 😊

 💪🏼 Interestingly, cooking (heat) may reduce protein availability in some foods (e.g. eggs) due to molecular bonds being broken (process known as protein denaturation), although it can increase the availability of other proteins by breaking the encapsulation layer (e.g. some plant proteins). Just another example showing how complex nutrition really is! 🙉🤯