Protein is important for maintaining muscle and bone mass, for keeping the immune
system strong, and to prevent fatigue.
People not familiar with vegan nutrition often assume it is terribly hard to get enough protein on a vegan diet, and that's if they even think there is any protein in plant foods at all (how they think vegans survive is an interesting question, though many of them probably don't think we do). On the other hand, once "educated", most vegans have the diametrically opposite view, considering it impossible for someone not to get enough protein on a vegan diet.
The truth lies somewhere in the middle. It is easy to get enough protein on a vegan diet if you eat multiple servings of legume-based foods each day. But there are many vegans who are probably not getting enough protein for optimal long-term health. If a vegan does not eat legume-based foods, it can be difficult to get enough of the amino acid lysine.
Vegans who do not eat enough calories to maintain their weight also need to pay special attention to making sure they are getting enough protein.
Twenty amino acids are used to build protein, but they are not the only amino acids. Carnitine and taurine are amino acids which are not building blocks of protein, but the discussion here is limited to the protein amino acids.
Because some amino acids are essential, the RDA for amino acids should be as important as the RDA for protein. But because the RDA for protein takes into account the RDA for amino acids, the amino acid RDA is rarely mentioned. The essential amino acids are found in fairly consistent amounts in average Western diets and the RDA for protein is calculated with typical diets in mind.
Proteins in the human body tend to have a consistent percentage of the essential amino acids. The percentages of essential amino acids in both animal and soy products closely mimic those found in human proteins, and they are, therefore, considered complete or high-quality protein. Non-soy plant proteins have a lower percentage of at least one amino acid, although all legume products are pretty close to soy.
Some people are under the false impression that all non-soy plant proteins are completely devoid of at least one essential amino acid. The truth is that all plant proteins have some of every essential amino acid (see Table 3). Legumes are lower in the amino acid methionine while most other plants foods are lower in lysine.
In an effort to make sure vegetarians were getting enough of all the amino acids, in the early 1970s in her book Diet for a Small Planet, Frances Moore Lappe popularized the idea of combining plant proteins at each meal in order to get a "complete" protein. By mixing beans and grains, you can make sure that you are getting both methionine and lysine at each meal.
It is now well known that our livers store the various essential amino acids and so it's not critical to combine different protein sources at each meal. The 2009 American Dietetic Association's Position Paper on Vegetarian Diets says:
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People not familiar with vegan nutrition often assume it is terribly hard to get enough protein on a vegan diet, and that's if they even think there is any protein in plant foods at all (how they think vegans survive is an interesting question, though many of them probably don't think we do). On the other hand, once "educated", most vegans have the diametrically opposite view, considering it impossible for someone not to get enough protein on a vegan diet.
The truth lies somewhere in the middle. It is easy to get enough protein on a vegan diet if you eat multiple servings of legume-based foods each day. But there are many vegans who are probably not getting enough protein for optimal long-term health. If a vegan does not eat legume-based foods, it can be difficult to get enough of the amino acid lysine.
Vegans who do not eat enough calories to maintain their weight also need to pay special attention to making sure they are getting enough protein.
High Quality or Complete Proteins
Proteins are made out of chains of amino acids. Some amino acids can be made by the
body (generally from other amino acids), but some cannot. The ones that cannot are known
as "essential" or "indispensable."Twenty amino acids are used to build protein, but they are not the only amino acids. Carnitine and taurine are amino acids which are not building blocks of protein, but the discussion here is limited to the protein amino acids.
Because some amino acids are essential, the RDA for amino acids should be as important as the RDA for protein. But because the RDA for protein takes into account the RDA for amino acids, the amino acid RDA is rarely mentioned. The essential amino acids are found in fairly consistent amounts in average Western diets and the RDA for protein is calculated with typical diets in mind.
Proteins in the human body tend to have a consistent percentage of the essential amino acids. The percentages of essential amino acids in both animal and soy products closely mimic those found in human proteins, and they are, therefore, considered complete or high-quality protein. Non-soy plant proteins have a lower percentage of at least one amino acid, although all legume products are pretty close to soy.
Some people are under the false impression that all non-soy plant proteins are completely devoid of at least one essential amino acid. The truth is that all plant proteins have some of every essential amino acid (see Table 3). Legumes are lower in the amino acid methionine while most other plants foods are lower in lysine.
In an effort to make sure vegetarians were getting enough of all the amino acids, in the early 1970s in her book Diet for a Small Planet, Frances Moore Lappe popularized the idea of combining plant proteins at each meal in order to get a "complete" protein. By mixing beans and grains, you can make sure that you are getting both methionine and lysine at each meal.
It is now well known that our livers store the various essential amino acids and so it's not critical to combine different protein sources at each meal. The 2009 American Dietetic Association's Position Paper on Vegetarian Diets says:
"Plant protein can meet requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults, thus complementary proteins do not need to be consumed at the same meal."For more information on which foods have "complete" proteins, see JackNorrisRd.com blog post, Complete Proteins.
Read The Complete Article Here