Carbohydrates, proteins, and fats are the three macronutrients our bodies can break down into energy or use as a building material. Our body readily uses carbohydrates and fats as fuel sources and while it can use protein as an energy source - it does so with reluctance.
Here’s why:
The word protein is rooted in the Greek word prōteîos meaning “primary” or “first”. It is responsible for nearly all of the work that is carried out in every cell and we need adequate dietary protein to maintain the structure, function, and regulation of every tissue and organ in our body. Protein influences numerous processes in the body and can impact everything from our satiety, hormones, and sleep to our mood, immunity, and detoxification capacity. Protein is also the key nutrient that feeds and repairs our muscles - the organ that is largely responsible for maintaining a healthy metabolism, as well as optimal body composition.
Protein Quality and Quantity Matters
Many of us know about the power of quality carbohydrates and fats. We understand the need to have them in balance when it comes to fuelling our bodies and, as a society, have become very clued up on what to look for when choosing the best sources for our health and well-being.
So the question is, what about protein quality and quantity?
Protein is not just protein. The quality of a protein source can be determined by three characteristics:
- the amount of protein in the food (how many grams of protein per serving)
- the number of essential amino acids in the protein source.
- the digestibility of the protein source.
Protein-rich foods contain a mix of essential and non-essential amino acids. Essential amino acids are the protein building blocks we cannot make ourselves and must consume from our food every day. Non-essential and conditional amino acids are ones we can make ourselves or only need more of then in times of stress and illness.
Plant-based protein sources are, in general, of lower quality and bioavailability than animal protein sources. They do not contain adequate levels of all of the 9 essential amino acids and often contain lower amounts of protein per serve. This is why when we eat plant-based protein sources we generally need larger amounts of these protein-rich plant foods to ensure adequate intake of net protein and to ensure we are meeting our daily essential amino acid requirements.
Complete sources of protein that contain all 9 essential amino acids are necessary for the growth and maintenance of every tissue in our bodies. This is because the body is constantly forming new tissues and replacing old ones. The rate of this protein turnover varies from tissue to tissue - for example, it takes 4-5 days to completely replace the intestinal mucosa in our gut, 3 months to replace every muscle cell, and almost 10+ years to replace our bone cells.
To form tissue and replace old tissue, the body needs all of our essential building blocks - our essential amino acids. When an essential amino acid is limited or unavailable, our bodies cannot complete new tissue formation - this can result in delayed healing, repair, rejuvenation, and poor overall function.
Of the 9 essential amino acids - Leucine, Methionine, and lysine are the most essential to human life.
Leucine is one of the 3 branched-chain amino acids (BCAA’s) our muscles utilize as fuel during exercise and is important for maintaining our metabolic well-being, physical health, and body composition. Leucine has a threshold (2.2-2.5g) dose per meal that needs to be met to stimulate muscle protein synthesis and boost metabolic health. Leucine works alongside the two other BCAAs, valine and isoleucine, to promote muscle health, performance, and greater metabolic health outcomes.
Methionine is a sulfur-containing amino acid needed for a critical number of processes including methylation. We need methylation to repair DNA damage, detoxify hormones, maintain our mental well-being, produce energy, and much much more.
These three extremely essential amino acids are low in plant-based protein sources but are readily available in all animal proteins. This is why animal-based proteins are considered to be of great importance in the human diet when it comes to health, healing, and ageing but also highlights the need for those following a plant-based diet to place greater emphasis on getting enough protein at every meal.
So How Do I Know If I Am Getting Enough?
Signs you may not be getting enough protein:
- Increased appetite
- Trouble losing weight (especially when you feel like nothing works)
- Trouble building muscle mass and loss of existing muscle mass
- Low energy levels and fatigue
- Poor concentration, focus, and memory
- Moodiness and mood swings
- Blood sugar swings
- Slow wound healing
- Low immunity
- Poor sleep
So How Do I Ensure I Get Enough Protein?
Regardless of whether you get your protein from plants or animals, literature suggests that adult bodies need > 1.2 g/kg of body weight at rest. This increases to 1.6g/kg for the recreational exerciser and between 1.6-2.2g/kg of body weight of the athlete, anyone eating a solely plant-based diet or using a caloric deficit to lose weight.
What does this look like in reality?
For a 60 kg female who enjoys regular exercise, 96g of net protein per day would be required to meet her need of 1.6g/kg of body weight. This could look like; 150g-160g of cooked salmon for breakfast, 114g-120g of cooked chicken breast for lunch, and 114g-120g of cooked ground beef for dinner.
For many people the idea of protein for breakfast is the hardest - this is why at the BePure Clinic we often recommend our clients use an allergy-friendly protein powder at breakfast. This quick, tasty, and easy protein option can be readily mixed into smoothies, porridge, and chia puddings.
