What about plant-based proteins?

Your body breaks down protein in foods into amino acids, which it then uses to make proteins for building muscles, skin, organs, connective tissues, bones, hair and nails. Protein is also needed for healthy immune function and to make enzymes and hormones.

Here, I will be focusing on the muscles.

Muscles are crucial for posture, movement, breathing, and protecting joints and organs.

To maintain, repair and build muscle tissue, the body will use available amino acids from the protein in your last meal to make the proteins it requires. This process is called muscle protein synthesis and requires two conditions to be met:

• All essential amino acids present
• Enough of the amino acid leucine

Research shows that an increase of around 2.6g of leucine in the bloodstream triggers muscle protein synthesis in 20-year-old healthy males. This amount is equivalent to that found in about 110g or 3.9oz of cooked lean beef.

As we age, we need more leucine at a meal – perhaps up to 4.4g (190g or 6.7oz cooked lean beef) to trigger this same process.

So, what about plant-based protein?

Remember, you need all essential amino acids present, plus adequate leucine.

Bean-based sources of protein do not contain all essential amino acids in sufficient quantities. Experts say you need to pair them with rice, for example, to ensure all amino acids are present. So how much would you need in one meal to meet your leucine threshold? About 2–3 cups (330–490g or 11.6–17.3oz) of cooked chickpeas plus 2–3 cups (390–585g or 13.8–20.6oz) of cooked rice! Is it possible to eat that much in one sitting?

Quinoa has all the essential amino acids, but to meet the 2.6–4.4g leucine threshold, you would need to eat 5.5–9.25 cups of cooked quinoa in one meal!

You can see that in order to eat enough plant-based protein per meal to meet the leucine threshold and ensure all essential amino acids are present, you need to be eating an awful lot!

Remember, I am talking about muscle maintenance and repair here, which is an essential bodily function.

I’ll be going more in-depth on the topic of protein in posts to come, including bioavailability.