Here are some frequently asked questions about protein and vegan nutrition.
What is protein?
Proteins are big molecules that are made up of chains of smaller molecules called amino acids. When you digest a protein, you break it down into the individual amino acids. When your cells make new protein, they put those amino acids back together, in a new order.
Which plant-based foods contain protein?
All living cells contain protein. As a result, all unrefined plant foods contain protein. Some refined foods of plant origin contain little or no protein. Examples include sugar and olive oil.
Do I need to worry about getting enough protein?
Human beings grow remarkably slowly. For that reason, our protein needs are remarkably small. Any practical diet based on ordinary plant-based foods would provide enough protein to meet normal human protein requirements, as long as the person is eating enough food to get enough calories. As Sir William Maddock Bayliss put it, if you take care of the calories, the protein takes care of itself.
Do I need to combine beans with grains to get a complete protein?
No. There is no need to combine different kinds of food in order the complement the proteins. We have known since the 1950s that ordinary staple foods, such as potatoes and rice, contain more than enough protein to meet human nutritional needs. This idea that you need to combine different kinds of food to get a balanced protein source came from studies of rats and pigs. Rats and pigs grow so fast that some feeds, such as corn, might not provide enough of all of the amino acids to allow them to grow as fast as possible. Since human beings grow much more slowly, the balance of amino acids in our food does not limit our growth.
Are vegans at risk for nutrient deficiencies?
Plants contain all but two of the nutrients that are essential in human nutrition. The two exceptions are vitamin D (the sunshine vitamin) and vitamin B12 (which is made by bacteria). A vitamin B12 supplement is the only supplement that is routinely recommended for people who eat a purely plant-based diet. Of course, some people, such as people with cystic fibrosis, have problems with absorbing nutrients from their food. If you have a digestive or metabolic disorder, you should ask a registered dietitian for dietary advice.
Are vegan babies at risk of malnutrition?
Babies that are being neglected are at risk for malnutrition. Babies thrive on breast milk from a healthy, well-fed vegan mother. Women who are pregnant or nursing should ask a registered dietitian for dietary advice.
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