Vegans need about 20% more protein than the standard recommendation, bringing the target from 0.8 grams per kilogram of body weight per day to roughly 1.0 g/kg. For a 150-pound (68 kg) person, that’s about 68 grams of protein daily instead of 54. The increase compensates for the lower digestibility of plant proteins compared to animal proteins, which means your body extracts less usable protein from each gram you eat.
Why Vegans Need More Than the Standard RDA
The official protein RDA of 0.8 g/kg/day was set for all adults, including vegans, but it was largely established using animal-protein studies. Plant proteins have a lower “biological value,” meaning your body converts less of what you eat into usable amino acids. A nitrogen balance study in minimally active male vegans found that participants needed about 12 extra grams of protein per day (factoring in a 74% digestibility rate for vegan diets) to offset what their bodies couldn’t absorb. That works out to roughly 0.96 g/kg/day.
Rounding up to 1.0 g/kg is a practical target for most adult vegans who aren’t highly active. If you weigh 70 kg (about 154 pounds), that’s 70 grams per day. At 80 kg (176 pounds), aim for 80 grams.
What Makes Plant Protein Less Efficient
Two things work against you. First, most plant proteins score lower on the DIAAS scale, which measures how well your body digests and uses the amino acids in a food. Egg, dairy, and meat proteins score above 100 (classified as “excellent”), while soy and whey score above 75 (“high quality”). Pea, rice, oat, fava bean, and hemp proteins all fall below 75. That doesn’t make them useless, but it means you need a larger serving or a smarter combination to get the same effect.
Second, plant foods contain natural compounds called antinutrients, particularly phytates and tannins, that interfere with protein and mineral absorption. Tannins reduce protein digestibility directly, while phytates block absorption of iron, zinc, and calcium. The good news: soaking beans and grains before cooking, sprouting seeds, and fermenting foods (think tempeh, miso, or sourdough bread) all reduce these compounds significantly.
The Lysine Factor
Lysine is the amino acid most likely to fall short on a vegan diet. Grains like rice, wheat, and oats contain very little of it relative to what your body needs. The estimated average requirement is 30 mg of lysine per kg of body weight per day, and research shows vegans average about 43 mg/kg, which is adequate but leaves less margin for error than omnivores have.
The fix is straightforward: eat legumes daily. Lentils, chickpeas, black beans, and soy foods are all rich in lysine. Nuts and seeds help too. As long as your diet includes a mix of legumes, nuts, and seeds alongside grains, lysine intake is unlikely to be a problem. You don’t need to combine them at every meal; your body pools amino acids throughout the day.
Protein Targets for Active Vegans
If you exercise regularly, the numbers go up. The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for athletes, and vegan athletes should aim toward the higher end of that range. In practice, that means:
- Endurance athletes (runners, cyclists): 1.4 to 1.6 g/kg/day
- Strength and power athletes (lifters, sprinters): 1.7 to 2.0 g/kg/day
- During a weight-loss phase: 1.8 to 2.7 g/kg/day, to preserve muscle mass while in a calorie deficit
For a 70 kg vegan who lifts weights, that’s 119 to 140 grams of protein per day. During a cutting phase, it could reach 189 grams, which takes genuine planning but is achievable with protein-dense foods and supplementation.
Targets for Older Adults
After age 65, protein needs rise regardless of diet because the body becomes less efficient at building and maintaining muscle. An international expert panel recommends 1.0 to 1.2 g/kg/day for older adults, with up to 1.5 g/kg/day for those managing chronic illness. Combining this protein with resistance exercise twice a week produces clear benefits for both muscle mass and leg strength.
For older vegans, adding the 20% digestibility buffer pushes the practical target to about 1.2 to 1.4 g/kg/day. Spreading intake across meals matters here too. Aiming for 25 to 30 grams of protein per meal helps maintain muscle protein synthesis throughout the day, which becomes especially important with aging.
Targets During Pregnancy and Breastfeeding
Pregnant vegans need an additional 25 grams of protein per day during the second and third trimesters, bringing the total to roughly 70 grams per day (or about 0.5 grams per pound of body weight). Protein needs during breastfeeding remain at the same elevated level. Because plant protein is less digestible, erring slightly above 70 grams is a reasonable approach.
Best Vegan Protein Sources
Not all plant foods are created equal when it comes to protein density. Per 100-gram serving:
- Tempeh: 20 g (fermented, so antinutrients are reduced)
- Seitan: 18 g (made from wheat gluten, very low in lysine)
- Lentils (cooked): 10.5 g
- Pumpkin seeds: 8.5 g
- Tofu (firm): 7 g per 85-gram serving
Soy foods (tofu, tempeh, edamame) are particularly valuable because soy is one of the few plant proteins that scores as “high quality” on digestibility scales and contains a strong amino acid profile, including lysine. Seitan is protein-dense but nearly devoid of lysine, so it works best paired with legumes rather than as your primary source.
Making Each Meal Count
Muscle protein synthesis is triggered by an amino acid called leucine. Research shows you need about 3 grams of leucine in a meal to fully activate the process. A 20-gram serving of whey protein hits that threshold easily, but a 20-gram serving of plant-based protein typically provides only about 1.5 grams of leucine, roughly half of what’s needed.
A recent study in young men and women found that when plant-based protein was fortified with extra leucine to reach the 3-gram mark, muscle protein synthesis increased by about 16% compared to the unforted plant protein, matching the response from whey. You can replicate this by either eating a larger portion of plant protein per meal (30 to 40 grams instead of 20) or by choosing leucine-rich plant foods. Soy, peanuts, and lentils are among the best plant sources of leucine.
Spreading your protein across three or four meals rather than loading it into one or two also helps. Each meal is a separate opportunity to trigger that synthesis response, so 30 grams at breakfast, lunch, and dinner will build more muscle than 10 grams at two meals and 70 at another.
Quick Reference by Body Weight
- 55 kg (121 lbs), general adult: ~55 g/day
- 70 kg (154 lbs), general adult: ~70 g/day
- 85 kg (187 lbs), general adult: ~85 g/day
- 70 kg, strength athlete: 119–140 g/day
- 70 kg, older adult (65+): 84–98 g/day
- Pregnant/breastfeeding (2nd–3rd trimester): ~70+ g/day
These numbers are higher than what you’ll see on most generic nutrition charts, which typically assume animal-protein diets. The adjustment isn’t dramatic, but it’s consistent: eating a wider variety of protein-rich plant foods, favoring legumes and soy, and paying attention to meal distribution will close the gap without requiring anything extreme.