How much protein do I need per day?

Around 0.8 g per kilogram daily for a healthy adult — roughly 56 g at 70 kg. Healthy older adults are often advised 1.0–1.2 g/kg; athletes commonly use 1.2–2.0 g/kg.

Do I have to combine rice and beans in the same meal?

No. The body pools amino acids across the day, so eating legumes and grains at different meals works equally well.

Is soy safe to eat daily?

Yes. Human studies show neutral-to-beneficial effects on hormones, breast cancer risk and cardiovascular markers at ordinary intakes of one to three servings per day.

What is the easiest high-protein plant meal?

Try lentils or chickpeas with a grain, olive oil and greens. Protein, preparation time and cost depend on portions, ingredients and whether the legumes are already cooked.

Do plant proteins absorb worse?

Some plant proteins are less digestible than animal proteins, with large differences between foods and processing methods. Adequate intake and varied protein sources help meet needs.

All guidesNutrition science9 min read

Protein on a plant-based diet: what the evidence actually says

Protein is a common worry on plant-based diets. Here is the requirement, the arithmetic, and the research on plant versus animal protein.

In short

The adult reference requirement is about 0.8 g of protein per kilogram of body weight per day; most people in high-income countries eat far more than that already.
Studies generally find adequate average protein intake in vegans; enough calories and protein-rich foods help meet individual needs.
Combining foods at every meal is unnecessary — the body maintains a free amino-acid pool across the day.
Higher plant-protein intake is associated with lower all-cause mortality; higher red and processed meat intake with the opposite.

Key numbers

0.8 g/kg

Reference protein requirement for healthy adults

US National Academies

1.0–1.2 g/kg

Suggested protein target for healthy older adults

ESPEN

18 g

Protein in one cooked cup of lentils

USDA FoodData Central

Not established

Protein-deficiency prevalence in adequate-calorie vegan diets

Mariotti & Gardner, 2019

The requirement is smaller than the marketing suggests

For a healthy 70 kg adult, the US protein reference intake is roughly 56 g per day. Meals containing oats, soy milk, lentils and tofu can meet this, depending on portions. Needs differ in pregnancy, older age and sport; athletes commonly use about 1.2–2.0 g/kg/day. Beans, soy, seitan, grains and nuts can contribute.

Amino acids: the 'incomplete protein' idea was retired decades ago

Most plant protein sources supply all nine essential amino acids, in differing proportions. Legumes tend to be lower in sulphur amino acids and grains in lysine. Eating varied protein sources across the day generally meets needs without deliberate pairing at each meal.

Soy has a favourable essential-amino-acid profile; quinoa, buckwheat, amaranth and hemp also contribute useful protein.
Lysine is the amino acid worth a thought: legumes, soy, seitan-plus-beans and pistachios cover it.
Digestibility varies by food and processing; cooking and other preparation methods can improve it.

Health outcomes track the package, not just the protein

Plant protein foods often supply fibre and unsaturated fat; some animal protein foods supply more saturated fat, and red meat supplies haem iron. Cohort analyses associate replacing some animal protein with plant protein with lower mortality. These observational findings do not isolate the effects of amino acids from the rest of the food or lifestyle.

Muscle: training and adequate protein both matter

Trials often find similar strength gains with plant and animal protein during resistance training, especially with adequate total intake. Some analyses favour animal protein for certain lean-mass outcomes. Plant proteins vary in leucine and digestibility; protein choice, portions and overall intake matter, particularly in older adults.

What actually goes wrong

Cutting animal foods without replacing their energy and protein can lead to inadequate intake. Build meals around legumes or soy, add grains and suitable fats, and check overall intake. Illness, restrictive eating and individual needs can also affect protein status.

The data

Protein per 100 g of common plant foods (USDA FoodData Central)

Peanuts25.8 g protein · raw
Tempeh20.3 g protein
Firm tofu17.3 g protein · calcium-set
Edamame11.9 g protein · cooked
Lentils9 g protein · boiled
Chickpeas8.9 g protein · boiled

At a glance

Approximate protein per 100 g as eaten, with illustrative servings; products vary

Food	Protein /100 g	Typical serving	Protein per serving
Red lentils	9 g	1 cup (200 g)	18 g
Chickpeas	9 g	1 cup (165 g)	15 g
Firm tofu	17 g	150 g block	26 g
Tempeh	19 g	100 g	19 g
Seitan	25 g	100 g	25 g
Soy milk	3.3 g	250 ml	8 g
Wholemeal pasta	5 g	180 g cooked	9 g
Peanut butter	25 g	2 tbsp (32 g)	8 g

Common objections

ClaimYou need animal protein to build muscle.

What the evidence showsPlant proteins can support muscle growth with resistance training and adequate intake. Trials often find similar strength gains, although some lean-mass outcomes favour animal protein.

ClaimPlant proteins are incomplete.

What the evidence showsMost plant protein sources supply all essential amino acids in different proportions. A varied diet with enough protein generally meets needs without pairing foods at every meal.

ClaimVegans are commonly protein-deficient.

What the evidence showsSurveys generally find adequate average vegan protein intake, but some people have low intake. Adequate calories and regular protein-rich foods are important.

Questions people ask

How much protein do I need per day?: Around 0.8 g per kilogram daily for a healthy adult — roughly 56 g at 70 kg. Healthy older adults are often advised 1.0–1.2 g/kg; athletes commonly use 1.2–2.0 g/kg.
Do I have to combine rice and beans in the same meal?: No. The body pools amino acids across the day, so eating legumes and grains at different meals works equally well.
Is soy safe to eat daily?: Yes. Human studies show neutral-to-beneficial effects on hormones, breast cancer risk and cardiovascular markers at ordinary intakes of one to three servings per day.
What is the easiest high-protein plant meal?: Try lentils or chickpeas with a grain, olive oil and greens. Protein, preparation time and cost depend on portions, ingredients and whether the legumes are already cooked.
Do plant proteins absorb worse?: Some plant proteins are less digestible than animal proteins, with large differences between foods and processing methods. Adequate intake and varied protein sources help meet needs.