Protein in the Vegan Diet -- The Vegetarian Resource Group (2024)

by Reed Mangels, PhD, RD
From Simply Vegan 5th Edition

Summary:It is easy for a vegan diet to meet recommendations for protein, aslong as calorie intake is adequate. Strict protein combining is notnecessary; it is more important to eat a varied diet throughout theday.

SomeAmericans are obsessed with protein. Vegans are bombarded withquestions about where they get their protein. Athletes used to eatthick steaks before competition because they thought it would improvetheir performance. Protein supplements are sold at health foodstores. This concern about protein is misplaced. Although protein iscertainly an essential nutrient which plays many key roles in the wayour bodies function, we do not need huge quantities of it. Only aboutone calorie out of every 10 we take in needs to come from protein.Vegan athletes, especially in the early stages of training, may havehigher protein needs than vegans who exercise moderately or who arenot active. Vegan athletes’ protein needs can range from 0.36 to0.86 grams of protein per pound ². Protein supplements are notneeded to achieve even the highest level of protein intake.

How muchprotein do we need? The RDA recommends that we take in 0.8 grams ofprotein for every kilogram that we weigh (or about 0.36 grams ofprotein per pound that we weigh) ¹. This recommendation includes agenerous safety factor for most people. When we make a fewadjustments to account for some plant proteins being digestedsomewhat differently from animal proteins and for the amino acid mixin some plant proteins, we arrive at a level of 0.9 gram of proteinper kilogram body weight (0.41 grams per pound). If we do a fewcalculations we see that the protein recommendation for vegansamounts to close to 10% of calories coming from protein. [Forexample, a vegan male weighing 174 pounds could have a calorierequirement of 2,600 calories. His protein needs are calculated as174 pounds x 0.41 g/pound = 71 grams of protein. 71 grams of proteinx 4 calories/gram of protein = 284 calories from protein. 284 dividedby 2,600 calories = 10.9% of calories from protein.] If we look atwhat vegans are eating, we find that, typically, between 10-12% ofcalories come from protein ³. This contrasts with the proteinintake of non-vegetarians, which is close to 14-18% of calories.

So, in theUnited States it appears that vegan diets are commonly lower inprotein than standard American diets. Remember, though, with protein,more (than the RDA) is not necessarily better. There do not appear tobe health advantages to consuming a high protein diet. Diets that arehigh in protein may even increase the risk of osteoporosis 4 andkidney disease ⁵.

Table 2 shows the amount of protein in various vegan foods and alsothe number of grams of protein per 100 calories. To meet proteinrecommendations, the typical moderately active adult male vegan needsonly 2.2 to 2.6 grams of protein per 100 calories and the typicalmoderately active adult female vegan needs only 2.3 to 2.8 grams ofprotein per 100 calories. These recommendations can be easily metfrom vegan sources.

It is veryeasy for a vegan diet to meet the recommendations for protein. Nearly all vegetables, beans, grains, nuts, and seeds contain some,and often much, protein. Fruits, sugars, fats, and alcohol do notprovide much protein, so a diet based only on these foods would havea good chance of being too low in protein. However, not many veganswe know live on only bananas, hard candy, margarine, and beer. Veganseating varied diets containing vegetables, beans, grains, nuts, andseeds rarely have any difficulty getting enough protein as long astheir diet contains enough energy (calories) to maintain weight. [SeeFeeding Vegan Kids, Pregnancy and the Vegan Diet, and the section on lactation (page 186, in Simply Vegan), for details about protein needs during these special times.]

What aboutcombining or complementing protein? Doesn’t that make the proteinissue much more complex? Let’s look at a little background on themyth of complementing proteins. Protein is made up of amino acids,often described as its building blocks. We actually have a biologicalrequirement for amino acids, not for protein. Humans cannot make nineof the twenty common amino acids, so these amino acids are consideredto be essential. In other words, we must get these amino acids fromour diets. We need all nine of these amino acids for our body to makeprotein.

Somepeople say that eggs, cow’s milk, meat, and fish are high qualityprotein. This means that they have large amounts of all the essentialamino acids. Soybeans, quinoa (a grain), and spinach also areconsidered high quality protein. Other protein sources of non-animalorigin usually have all of the essential amino acids, but the amountsof one or two of these amino acids may be low. For example, grainsare lower in lysine (an essential amino acid) and legumes are lowerin methionine (another essential amino acid) than those proteinsources designated as high quality protein.

FrancesMoore Lappe, in her book Diet for a Small Planet ⁶ advocated thecombining of a food low in one amino acid with another foodcontaining large amounts of that amino acid. This got to be a verycomplicated process, with each meal having specific amounts ofcertain foods in order to be certain of getting a favorable aminoacid mix. Many people got discouraged with the complexity of thisapproach. Actually, Lappe was being overly conservative to avoidcriticism from the “Nutrition Establishment.” She has sincerepudiated strict protein combining, saying, “In combating the myththat meat is the only way to get high quality protein, I reinforcedanother myth. I gave the impression that in order to get enoughprotein without meat, considerable care was needed in choosing foods.Actually it is much easier than I thought” ⁷.

Werecommend eating a variety of unrefined grains, legumes, seeds, nuts,and vegetables throughout the day, so that if one food is low in aparticular essential amino acid, another food will make up thisdeficit 8,9.

As anextreme example, even if you only ate one kind of grain, bean,potato, or vegetable as a protein source, and ate enough of thatfood, you could meet your protein and amino acid needs. Admittedly,it would be a very monotonous way to eat and you might miss out onother nutrients. We point this out, however, to illustrate the ideathat almost all non-animal protein sources contain all of theessential amino acids. Table 3 above shows the amount of rice,corn, potatoes, or tofu that an adult male would need to eat if herelied on only one food as a protein source. Women would need about20% less food because of women’s lower protein requirements.

See Gluten free diet and protein sources.
See .

References

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