An increasing number of people ask about whether it's possible to sustain a vegan / vegetarian diet whilst getting enough proteins. With some of the richest sources of protein including beef, chicken, fish and eggs, many people are of the opinion that without these foods you can't possibly get enough protein in your diet. Whilst it may be the most straightforward way of reaching the recommended protein intake in terms of throwing together a meal and guaranteeing sufficient intake (see protein requirements below), in a world where more and more people are becoming aware of the the consequences of meat consumption on our individual health and that of our planet, it's important we understand how we can source proteins elsewhere in our diets.
Know your proteins
Proteins are the building blocks for life and play a hugely important role within every living organism. They form everything from our DNA to our hormones, enzymes and cells!
A protein is made up of smaller monomers called amino acids. Of the 20 amino acids used in the human body, there are 8 called ‘essential amino acids’. The body cannot manufacture these amino acids itself and therefore they must be sourced from the diet.
They include: Phenylalanine, Valine, Leucine, Isoleucine, Lysine, Threonine, Tryptophan, and finally Methionine. Histidine is essential for infants, but not for adults.
Animal vs. Plant-based Sources
Animal sources are ‘complete’ protein sources, which means they contain all the essential amino acids, whereas most plant foods do not. However, it’s a common misconception that you need to get your protein from meat. Even though there are certain amino acids in meat that are lacking in plant-based sources, you can still obtain all the essential amino acids from a vegetarian diet. The key is to eat a balanced and varied diet!
The following plant-based sources are in fact complete proteins, meaning they contain all the essential amino acids the body needs:
Quinoa (8 grams of protein / 1 cup)
Buckwheat (6 grams of protein / 1 cup)
Soy: tofu (10 grams / ½ cup) or tempeh (15 grams / ½ cup). N.B. the harder the tofu, the more protein it contains!
Chia seeds (4 grams / 2 tablespoons)
Eggs are also a great source of complete protein for vegetarians
Other foods such as nuts, seeds, legumes, grains and vegetables can be good sources of protein however they are considered ‘incomplete proteins’ because they are missing one or more of the essential amino acids. The 4 essential amino acids missing from most plant foods are lysine, tryptophan, methionine and phenylalanine (see sources below).
This is where food paring and variety comes in. For example, beans are high in the amino acid lysine but low in methionine. Rice, on the other hand, is low in lysine but high in methionine. When you put them together, you have the perfect pair and therefore as long as you regularly consume your complete proteins (listed above) and consume plant-based foods in combination e.g. rice and beans, they you’re good to go!
LYSINE: Beans, hemp seeds, chia seeds, spirulina, avocados, soy (tofu, tempeh), almonds, cashews, lentils and chickpeas
TRYPTOPHAN: Spinach, asparagus, nuts (almonds), peanuts, sesame seeds, pumpkin seeds, soy (tofu, tempeh), oats, hemp seeds, chia seeds, avocados, bananas, quinoa, lentils, leafy green vegetables, mushrooms, carrots, peppers, chickpeas
METHIONINE: Sunflower seeds & butter, hemp seeds, chia seeds, brazil nuts, oats, figs, whole grain rice, beans, legumes, onions, cacao, raisins
PHENYLALANINE: Pinto beans, peanuts, pumpkin seeds, sesame seeds, pecans, chickpeas, lentils, rice, avocado, almonds, leafy green vegetables, olives
Calculating Your Intake
To calculate your recommended intake of protein (average man & women):
0.8 grams per kilo of your body weight e.g. 0.8 x 80kg = 64g protein per day
There are some useful apps and websites for helping you calculate your dietary intake, including:
My Fitness Pal (app)
If you’re exercising, you may want to consider buying a protein powder. Pea and hemp protein powders are good choices as they are complete protein sources containing all the amino acids your body needs. Note that some aren’t the tastiest so shop around and read reviews!