This is one that you see echoed a lot by people as soon as they hear you're a vegan (or even a vegetarian) “but where will you get your protein?!”. Most people seem to think that protein is only found in meat. Luckily for us, they're wrong. There are many different sources of protein and it's easy for vegans to get their RDI (recommended daily intake) of protein. It is, however, important to eat a variety of foods throughout the day in order to get all the different essential amino acids. In this post we'll look at why protein is important, how much you need, how much vegans tend to get, different amino acids and how to get them, and food combining.
I am not a dietitian or a nutritionist and I encourage you to talk to a professional before making changes to your diet. This information is intended to be educational and for general interest only and is not intended to be used as nutritional advice.
Protein is used in a variety of different bodily functions. When we eat protein, our bodies break it down and use the amino acids from these proteins to build the proteins we need (Better Health Channel 2011). Protein is used to “build connective tissue, cell membranes and muscle cells” and are used to transport things around the body (Australian Institute of Sport Sports Nutrition 2009). Some of the major sources of protein in a vegan diet are beans, nuts, vegetables and grains. Below is a table of some of the top plant sources of protein, using data from an article on protein by Reed Mangels (n.d.).
Adult humans require between 46 and 64 grams of protein per day. A more detailed look at the RDIs by the Australian Government National Health and Medical Research Centre and New Zealand Ministry of Health (n.d.) can be seen in the table below. These will vary depending on things like age, if you're pregnant or lactating, how healthy you are and how active you are (Australian Government National Health and Medical Research Centre and New Zealand Ministry of Health n.d.).
*I assume that 'women' here refers to people who are assigned female at birth and have a lower level of testosterone production. 'Men' in this grouping seems to refer to people whose bodies produce large amounts of testosterone, which affects protein needs. I am unsure of the affects of taking testosterone on protein needs and encourage people who do this to talk to a doctor or other medical professional.
Vegans have been found to have relatively lower intakes of protein than non-vegans (Key, Appleby & Rosell 2006; Marsh, Munn & Baines 2012). A study on vegans in Germany found that while the majority of vegans had protein intakes that were within the recommended range, many (over 30%) had low intakes and it was recommended that they should consume more protein (Waldmannet al 2003). Even though vegans have been found to have a relatively lower average intake than non-vegans, vegans are more than capable of getting their required protein intake from plants. There are also vegan protein powders available for people if they choose to use those. These are usually used by vegan athletes and bodybuilders. If you'd like to learn more about being a vegan bodybuilder or athlete, head to Vegan Bodybuilding & Fitness.
There are 20 amino acids that the human body utilises to create proteins. Some of these have to be obtained from food and the rest we can make ourselves. The ones that have to be obtained from food are called 'essential' amino acids. There are nine of these and all of them are found, in varying quantities, in plant foods (Australian Government National Health and Medical Research Centre and New Zealand Ministry of Health n.d.). Below I've put together a list of these amino acids and some of the places you can find them, thanks to Self Nutrition Data's website (where you can find many more foods listed). The format is Amino Acid: name of food (mg/200 calories).
Histidine: spirulina (862), kidney beans (818), soy bean tofu (921), mung beans (600)
Isoleucine: spirulina (2213), pak-choi (1483), spinach (1322), alfalfa sprouts (1243)
Leucine: kidney beans (2103), alfalfa sprouts (2322), zucchini (1514), tofu (1650)
Lysine: watercress (2436), mushrooms (1867), kidney beans (1667), asparagus (1555)
Methionine: spinach (478), zucchini (371), mushrooms (356), broccoli (264)
Phenylalanine: pinto beans (940), navy beans (915), sprouted lentils (859), cos lettuce (765)
Threonine: spinach (1104), navy beans (770), broccoli (772), cauliflower (694)
Tryptophan: mung beans (317), kidney beans (303), oat bran (285), cauliflower (247)
Valine: white mushrooms (1931), pak-choi (1150), broccoli (1014), brussel sprouts (65)0)
If a food has all nine essential amino acids in it in the right proportions, it is referred to as a 'complete protein'. Most animal-based foods contain all essential amino acids. Contrary to popular belief however, you don't have to eat all these amino acids in one meal; you can eat a variety of foods that contain all the essential amino acids over the course of a day and still get all that you need (Marsh, Munn & Baines 2012). If you're concerned, it is very easy to combine different food groups to get complete proteins. For example, you can combine cereals and legumes (baked beans on toast) to get all the essential amino acids you need (Better Health Channel 2011).
Protein is very important for health. While it has been found that vegans and vegetarians do have a lower than average intake of protein, they are able to get everything that they need from plants. They can do this by eating protein-rich foods and making sure to eat a variety of foods to get all nine essential amino acids. Therefore, it's completely possible and, for most people, easy to get enough protein on a plant-based diet.
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A big thank you to my friends for proof-reading my posts.
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