Protein

“Where do you get your protein?” is the question every vegan has heard, and it is almost always a bad question — not because protein doesn’t matter (it does, a lot), but because the premise is backwards. Plant-based diets, built on ordinary whole foods, overshoot protein requirements for nearly everyone without any special planning. The real question is not whether a vegan can get enough protein, but why an entire generation of eaters has been trained to worry about a problem they do not have.

This pillar covers what protein is, how much you need, the “complete protein” myth, practical daily targets, the best plant sources, and the handful of situations where more deliberate planning pays off (athletes, seniors, rapid-growth life stages).

What protein is

Protein is a macronutrient built from 20 amino acids. Nine of those are “essential” — meaning the human body cannot synthesize them and must take them in through food. The other eleven can be built from what’s on hand.

When you eat protein, your body does not use it as protein. It breaks the chains down into their component amino acids and reassembles them into the proteins you need: muscle fibers, enzymes, antibodies, hormones, structural tissues, skin and hair. Every protein-containing food you eat contributes amino acids to a shared pool from which your body builds what it needs.

How much you actually need

The official numbers:

• RDA (U.S.): 0.8 g per kg of body weight per day.
• EAR (estimated average requirement): 0.66 g/kg — where the RDA safety margin starts.

In practice, most nutrition researchers now think the RDA is the floor, not the ceiling. More protein is better for:

• Older adults — 1.0–1.2 g/kg to resist sarcopenia (age-related muscle loss).
• Athletes and strength trainees — 1.4–2.0 g/kg to maximize training adaptations.
• Weight loss — 1.2–1.6 g/kg to preserve lean mass in a calorie deficit and keep satiety high.

For a 70 kg (~154 lb) sedentary adult, that translates to:

• Minimum: 56 g/day (RDA)
• Comfortable: 70–90 g/day
• Training hard: ~100–140 g/day

These targets are easy to hit on a plant-based diet. You simply have to actually eat.

The “incomplete protein” myth

The idea that plant proteins are “incomplete” is one of the most persistent errors in popular nutrition writing. It comes from a misreading of Frances Moore Lappé’s Diet for a Small Planet (1971), which was based on methodology that was outdated within a decade.

Here’s what’s actually true:

1. Every whole plant food contains all nine essential amino acids. Not one is missing from rice, wheat, beans, lentils, oats, potatoes, or spinach. They differ in proportions, not presence.
2. “Protein combining” at a single meal is unnecessary. The body maintains an amino-acid pool over a 24-hour window. Eating rice at noon and beans at dinner has identical effect to eating them together.
3. The Academy of Nutrition and Dietetics has explicitly retracted combining recommendations in every edition of its position paper since the 1990s.

Some plant foods are relatively lower in one particular amino acid (legumes are modestly low in methionine; grains are modestly low in lysine). But eating a varied plant-based diet over the course of a day covers every requirement by default. You do not need to calculate.

Digestibility and DIAAS

The modern way to score protein quality is DIAAS (Digestible Indispensable Amino Acid Score), which measures both amino acid profile and how much of each amino acid the body actually absorbs.

Typical DIAAS scores:

• Cow’s milk: ~1.2
• Eggs: ~1.1
• Beef: ~1.0
• Soy protein isolate: ~0.9
• Tofu / soybeans: ~0.9
• Chickpeas: ~0.8
• Wheat: ~0.4
• Rice: ~0.6

Plants score lower on average, but two things matter more than the raw number. First, in practice people eat combinations (rice + beans = ~0.8). Second, DIAAS is calibrated for minimum adequacy, not maximum benefit — for a healthy adult consuming adequate total calories and varied whole foods, the differences largely vanish.

Top plant protein sources

Rough protein per typical serving:

Food	Serving	Protein (g)
Seitan	100 g cooked	21–25
Tempeh	100 g	19
Firm tofu	100 g	15–17
Edamame	1 cup	17
Lentils, cooked	1 cup	18
Black beans, cooked	1 cup	15
Chickpeas, cooked	1 cup	14
Peanut butter	2 tbsp	8
Soy milk (unsweetened)	1 cup	7
Hemp seeds	3 tbsp	9
Pumpkin seeds	1/4 cup	9
Quinoa, cooked	1 cup	8
Oats, dry	1/2 cup	7

A sample day hitting 100 g of protein easily:

• Breakfast: oatmeal with soy milk + 2 tbsp peanut butter + 1 tbsp hemp seeds → ~25 g
• Lunch: tempeh wrap with hummus and vegetables → ~30 g
• Snack: edamame → ~17 g
• Dinner: lentil stew with brown rice → ~28 g
• Total: ~100 g

No powders, no tracking apps, no fancy shopping.

For athletes

Plant-based athletes win titles, set world records, and out-train omnivorous peers. The practical guidance:

• Aim for 1.6–2.0 g/kg per day, distributed across 4–5 meals of ~25–40 g each.
• Lean on soy, seitan, legumes, and — if convenient — a pea/soy/rice protein powder to close gaps.
• Post-workout nutrition benefits from ~0.3 g/kg of protein within a couple of hours; a scoop of pea protein or a large bowl of lentils does the job.

For seniors

Older adults preserve muscle better at ~1.0–1.2 g/kg, with protein spread evenly across meals (not loaded into one big dinner). Plant-based options work, but pay particular attention to:

• Total intake — appetite shrinks with age; deliberately prioritize legumes and soy.
• Leucine threshold — each meal ideally contains at least 2–3 g of leucine to trigger muscle protein synthesis. Soy, tempeh, seitan, and lentils hit this; a salad with a sprinkle of chickpeas may not.
• Resistance training — matters more than protein source. Muscle is built by lifting, not by drinking.

Common misconceptions

• “You need animal protein for muscle growth.” Meta-analyses of resistance training show no significant difference between animal- and plant-protein supplementation for strength and hypertrophy when total protein and training are matched.
• “Plant protein causes kidney stress.” Not in healthy kidneys at realistic intakes. In people with existing kidney disease, plant protein is actually easier on the kidneys than animal protein.
• “Soy causes hormonal problems in men.” The best available meta-analyses — including Messina 2021 — find no effect on testosterone or estrogen in men at realistic dietary levels.
• “You need to eat protein immediately after working out.” The “anabolic window” is wider than marketing suggests — several hours on either side of training is fine.

What the evidence does not say

• It does not say protein doesn’t matter. It does, especially as you age.
• It does not say that plant and animal proteins are identical at the amino acid level. They differ. The practical consequences for varied plant-based eaters are minimal to none.
• It does not say everyone should eat high-protein. Endurance athletes, sedentary seniors, and strength-training teenagers all have different optimal intakes.

The punchline

Protein is almost a solved problem for vegans. Eat legumes, soy foods, and whole grains every day. Throw in some nuts, seeds, and the occasional protein-forward meal built around tempeh, tofu, or seitan. You will meet or exceed your needs without thinking about it.

If you are an athlete, senior, or in a high-demand life stage, track for a week or two to calibrate. After that, eat normally and enjoy your dinner.