Do vegans get enough protein? How much you need, and who falls short

Most vegans get enough protein. In the UK’s EPIC-Oxford study, vegans averaged 0.99 g a day per kilogram of body weight, above the 0.83 g recommended dietary allowance. The average hides a minority, though: 16.5% of the vegan men and 8.1% of the women reported intakes below the estimated average requirement.

Those two percentages are the part worth reading. They come from EPIC-Oxford’s own comparison of each vegan’s reported intake with the estimated average requirement (EAR) of 0.66 g per kg, as reported in a 2019 review by Mariotti and Gardner, who estimated the confidence intervals at 12.1% to 20.9% for the men and 5.8% to 10.4% for the women. That is roughly 1 in 6 men and 1 in 12 women (our arithmetic). The review’s reading is that these survey results “tend to indicate that a small fraction of vegans may have an insufficient protein intake,” and that this “may be obscured by a much higher and very sufficient intake in the overall population”. So “vegans get plenty” and “some vegans may not” are both true, and which one applies to you depends on your plate rather than your label. If you eat a lot of seitan, tempeh and tofu, our guide to meat substitutes has their protein per serving.

How much protein you need

The reference figures the review uses are 0.83 g per kg of body weight a day, the RDA, which meets or exceeds the requirement of 97.5% of people, and 0.66 g per kg, the EAR. Here is what 0.83 g comes to at a few body weights (our arithmetic, rounded):

Body weight	Protein a day at 0.83 g/kg
130 lb (59 kg)	about 49 g
150 lb (68 kg)	about 56 g
180 lb (82 kg)	about 68 g
200 lb (91 kg)	about 75 g

The old version of this page put a 150 lb vegan at “54 to 68 grams” at the basic level, which mixes up the grams and the kilograms. 150 lb is about 68 kg (our arithmetic).

Do vegans need more than that, to make up for plant protein? The review answers with the studies that measure requirements directly. A meta-regression of nitrogen balance studies by Rand and colleagues found no differences between animal, vegetable and mixed protein sources, which the review reads as suggesting a similar total protein requirement; it notes that the vegetable diets in those studies mixed cereals and legumes or used good-quality soy, with no rice-only or bean-only diets.

Training changes the target. The International Society of Sports Nutrition puts 1.4 to 2.0 g per kg a day as sufficient for most exercising people building or keeping muscle, which for the same 150 lb person is roughly 95 to 136 g (our arithmetic). Older adults are less settled; the review notes it remains a matter of debate whether their requirement is higher, or only higher in the frail elderly, and that France has set its RDA for older adults at 1 g per kg while other agencies have not endorsed a higher one.

Where the grams come from

Legumes fill most of the table below, and per gram, seitan and tofu are the densest (our arithmetic). By USDA’s figures, plus Upton’s label for the seitan (our arithmetic for the serving sizes):

Food	Serving	Protein
Firm tofu made with calcium sulfate	½ cup, 126 g	about 21.8 g
Upton’s Naturals Traditional Seitan	2 oz, 57 g	18 g
Lentils, cooked	1 cup, 198 g	about 17.9 g
Black beans, cooked	1 cup, 172 g	about 15.2 g
Chickpeas, cooked	1 cup, 164 g	about 14.5 g
Quinoa, cooked	1 cup, 185 g	about 8.1 g
Peanut butter	2 tbsp, 32 g	about 7.1 g

The seitan’s first ingredient after water is vital wheat gluten. Half a cup of tofu, a cup of lentils and a cup of chickpeas add up to about 54 g before breakfast toast or a spoon of peanut butter enters the picture (our arithmetic). Quinoa’s reputation outruns its numbers. A cooked cup has about 8.1 g, under 40% of what half a cup of tofu carries (our arithmetic). That is not a reason to skip it, only a reason not to count it as the protein.

Do you have to combine proteins?

Not at every meal. The review takes on the old advice to pair proteins within each meal and finds no evidence yet that isolated single plant proteins need to be supplemented with other proteins in the same meal; a reasonable variety of sources over the course of the day “appears to be appropriate”. When diets are at least slightly varied, the authors call strict attention to complementary amino acid patterns “simply over-precautious”.

Lysine is the amino acid that comes up. For the EPIC-Oxford vegans, based on an average body weight of 65 kg, the review calculated lysine intakes of 43 mg per kg against an estimated average requirement of 30 mg per kg, and concludes that an insufficient lysine intake “is not therefore expected”. It sees a possible limit only for vegans with a low protein intake whose protein would come from grains alone, which it calls “an unrealistic situation in developed countries”.

Who should look harder

The review’s reassurance is for adults whose diets are at least slightly varied. It names its own exceptions, people who are not eating enough energy and people who habitually avoid “legumes, nuts and seeds, or protein-rich analogs”. Among older adults, it expects a marginal intake to be most likely in elderly vegan women of small stature with an inactive lifestyle. It also cites a French NutriNet-Santé figure, 27% of vegans getting less than 10% of their energy from protein, the lower bound of acceptable intake, and calls that comparison an indirect assessment. Training is a separate case, a higher target rather than a risk group, and the ISSN range above is the one to use. If any of that sounds like you, count a few ordinary days against the tables above, and take the numbers to a registered dietitian if they come up short.

Where the evidence stops

The part I’m least sure about is how many vegans are truly short. Standard intake methods, questionnaires and recalls alike, are good at ranking people from lower to higher intake and weak on absolute numbers, the review says, with the largest uncertainties at both the low and the high end, and those uncertainties “tend to overestimate the proportion of individuals with insufficient intakes”. So the 16.5% and 8.1% may be high. Direct markers don’t settle it either way: the review finds no evidence of protein deficiency among vegetarians in Western countries, from what it calls a small number of studies. I would still rather a reader check their own plate than borrow the average. If you have counted and food alone doesn’t get you to your number, our comparison of vegan protein powders ranks them on lead.