Plant-based protein, without the hand-waving
You can hit any reasonable protein target on a plant-based diet. It takes more deliberate planning than an omnivorous one, and the reasons why are more interesting than the usual argument suggests.
The short answer
Plant-based protein works. It's less convenient, not less viable.
Two genuine differences are worth understanding, and then a third claim you can safely discard:
- Digestibility. Plant proteins are typically absorbed slightly less completely than animal proteins — the gap is usually in the range of 5–15%.
- Leucine content. Plant proteins are generally lower in leucine, the amino acid that acts as the main trigger for muscle protein synthesis. This matters most if you're training to build muscle.
- Protein combining — this one is a myth. More on that below.
The practical response to the first two is the same: eat somewhat more, and lean on the denser sources. Adding roughly 10–20% to your target covers it.
The sources that actually deliver
Per 100 g, cooked or as eaten unless stated.
| Food | Protein per 100 g | Notes |
|---|---|---|
| Seitan | 25 g | Wheat gluten — the densest of the lot. Not coeliac-friendly. |
| Tempeh | 19 g | Fermented soy. Firm, nutty, holds up to frying. |
| Firm tofu | 17 g | Silken is much lower, around 5 g. Press it first. |
| Edamame | 11 g | The easiest high-protein snack on this list. |
| Lentils, cooked | 9 g | Cheap, filling, and a genuine staple. |
| Black beans, cooked | 9 g | Similar for chickpeas and kidney beans. |
| Peanuts | 26 g | Also 49 g of fat. A fat source with protein in it. |
| Pumpkin seeds | 30 g | Dense but calorie-heavy; good as a topping. |
| Quinoa, cooked | 4 g | Far lower than its reputation implies. |
| Wholemeal bread | 13 g | Small amounts add up across a day. |
| Soy milk | 3 g | Roughly matches dairy milk. Almond milk is about 0.5 g. |
| Pea protein powder | 80 g | Isolated. Neutral-tasting versions exist; shop around. |
Two entries worth pausing on. Quinoa's protein reputation comes from it being a complete protein, which is true and largely irrelevant — at 4 g per 100 g cooked, you would need an implausible quantity for it to matter. And nuts are a fat source: excellent food, poor protein strategy.
Why digestibility matters, and how much
Not all protein you eat is absorbed and used. Nutritionists score this with DIAAS, the FAO's recommended measure of protein quality, which accounts for both how completely a protein is digested and whether it supplies all the essential amino acids in useful proportions.
On that scale, animal proteins like whey, egg and milk score above 1.0. Soy sits around 0.9. Most legumes and grains land between 0.5 and 0.8, held back by being low in one particular amino acid — lysine in grains, methionine in legumes.
This is a real effect but a modest one, and it's routinely overstated in both directions. It doesn't mean plant protein doesn't count. It means that if your target is 130 g, aiming for around 150 g from mostly plant sources gets you to the same place.
The protein-combining myth
You may have been told that plant proteins are "incomplete" and must be paired within a single meal — rice with beans, hummus with pitta — to form a complete protein.
This idea comes from Frances Moore Lappé's 1971 book Diet for a Small Planet. It was influential, it was wrong, and Lappé herself removed the claim from the 1981 edition after the evidence went against it.
The reason it doesn't hold: your body maintains a circulating pool of amino acids, replenished from food and from ordinary protein turnover in your own tissues. Amino acids eaten at breakfast are still available at lunch. There's no requirement to assemble a complete profile at each sitting.
What remains true is the underlying nutritional point, just at the scale of a day rather than a meal: eat a variety of plant protein sources and the profile takes care of itself. Beans and grains still complement each other well. You just don't need to eat them off the same plate.
If you're training
This is where the leucine difference earns attention. Muscle protein synthesis responds to a leucine threshold — roughly 2.5–3 g in a meal — and plant proteins carry less leucine per gram than animal ones.
Two straightforward adjustments:
- Larger doses per meal. Where an omnivore might get a full response from 25 g of whey, a plant-based equivalent may need 35–40 g to clear the same threshold.
- Favour soy and pea. Both are relatively leucine-rich for plant sources. Soy in particular has held up well in direct trials against animal protein for muscle gain when total intake is matched.
The overall picture from the research is reassuring: when total protein is adequate, differences in muscle and strength outcomes between plant-based and omnivorous diets are small. "Adequate" is doing real work in that sentence, which is the whole argument for tracking it.
A day that gets to 130 g
- Breakfast: 250 g soy yoghurt, 30 g pumpkin seeds, 40 g oats — about 25 g.
- Lunch: lentil and chickpea salad, 200 g cooked legumes, wholemeal pitta — about 28 g.
- Snack: 150 g edamame — about 17 g.
- Dinner: 200 g firm tofu or tempeh stir-fry with 200 g cooked rice — about 44 g.
- Evening: pea protein shake with soy milk — about 28 g.
That's roughly 140 g, comfortably above a 130 g target once you allow for digestibility. It also illustrates the real difference from an omnivorous diet: the protein arrives in a lot of small instalments rather than two or three large ones, which is precisely the situation where keeping a running total beats trying to remember.
Common questions
Can you get enough protein on a vegan diet?
Yes. Legumes, soy products, seitan, and whole grains can comfortably cover any normal target. It takes more planning than an omnivorous diet because plant foods are generally less protein-dense per calorie, and because plant protein is somewhat less efficiently used by the body.
Do vegans need more protein than meat eaters?
Somewhat. Plant proteins are typically digested slightly less completely and are lower in leucine, the amino acid that most strongly triggers muscle protein synthesis. A reasonable adjustment is to add about 10–20% to your target, or roughly 0.2–0.3 g per kilogram of body weight.
Do you need to combine plant proteins at every meal?
No. The idea that plant proteins must be carefully paired within a single meal was popularised in the 1970s and later retracted by its own author. The body maintains a pool of amino acids, so what matters is the variety across your day, not within each sitting.
What is the highest protein plant food?
Seitan, at roughly 25 g per 100 g, and it's mostly protein by calories. Among whole foods, tempeh (19 g), firm tofu (17 g) and lentils (9 g cooked) are the practical workhorses.
Plant-based makes tracking more useful, not less
When your protein arrives 8 g at a time across the whole day rather than 40 g at dinner, mental arithmetic stops working. PRO.TEIN tracks the one number and shows you the year as a calendar of squares.
Where these numbers come from
Protein values are typical figures from the USDA FoodData Central database. The digestibility discussion draws on the FAO's DIAAS framework, which replaced PDCAAS as the recommended method for scoring protein quality. The leucine threshold discussion draws on van Vliet, Burd and van Loon's 2015 review in the Journal of Nutrition. The complete-protein combining claim originated in Frances Moore Lappé's Diet for a Small Planet (1971), a position she publicly revised in the 1981 edition.
This is general information, not medical advice. It can't account for your circumstances. If you have kidney or liver disease, diabetes, are pregnant or breastfeeding, or are managing any medical condition, your protein needs may differ substantially — speak to a doctor or registered dietitian before changing your diet.