Plant protein: role, food sources and daily intake

In short:

1. Protein, whether from plants or animals, contributes to an increase in muscle mass and to the maintenance of normal bones, according to the EU register of claims.
2. Reference benchmark: 0.83 g of protein per kilo of body weight per day for adults, including food, according to EFSA.
3. Legumes, soy, whole grains, nuts and seeds are the best food sources of plant protein.
4. Combining legumes and grains across the day, not necessarily at the same meal, covers all 9 essential amino acids.

Plant protein interests more and more people: vegetarians, vegans, athletes cutting back on dairy, or simply those curious to diversify their sources. What remains is to find out what is actually established about its role, how much is needed each day, and which foods provide the most. This fact sheet sets out what is established.

Plant protein at a glance

What is plant protein, and what does the register of claims say

Plant protein is protein whose source is a plant: legumes, soy, grains, nuts or seeds, as opposed to animal protein (meat, fish, eggs, dairy).

In Europe, the EU register of nutrition and health claims¹ recognises two claims for protein, with no distinction of origin: it contributes to an increase in muscle mass, and it contributes to the maintenance of normal bones. These claims apply to any food that is a source of protein, whether dairy, egg or plant, provided the food supplies a sufficient amount¹.

How much protein do you need per day

The reference benchmark published by EFSA² (population reference intake) is 0.83 g of protein per kilo of body weight per day for adults, including food. This figure corresponds to an average requirement of 0.66 g/kg/day, increased to cover the needs of 97.5% of the population.

According to the European surveys cited by EFSA², actual average adult intake is most often already at or above this 0.83 g/kg/day benchmark, including ordinary food intake.

Who should pay particular attention to their intake

• Vegetarians and vegans: a well-planned plant-based diet, with varied sources and sufficient energy intake, covers protein and essential amino acid needs, according to the Academy of Nutrition and Dietetics³. The risk mainly comes from a diet that is not varied enough or insufficient in calories.
• Older adults: appetite and digestive absorption often decrease with age, which can reduce protein intake even though needs do not fall. Medical or dietary advice helps adjust the diet.
• Kidney disease: some kidney diseases require limiting protein intake. No dietary change or supplement without medical advice in this case.
• Athletes on a calorie-restricted diet: reducing calories while maintaining sufficient protein intake helps preserve muscle mass; a health or sports professional can help adjust the amounts.

The best food sources of plant protein

For the exact content of each food, the ANSES Ciqual table⁴ gives the detailed nutritional composition of foods eaten in France.

Combining plant proteins well

Taken on its own, a legume is generally low in sulphur-containing amino acids (methionine, cysteine), while a grain is generally low in lysine. Combining the two families covers all 9 essential amino acids⁵, which explains the popularity of pairings such as lentils and rice, or chickpeas and couscous.

Soy and quinoa are exceptions: their amino acid profile is considered complete on its own, making them useful sources for anyone who does not eat animal products.

Plant proteins also exist as concentrated powders (pea, soy or rice isolate, or blends), used in sports nutrition as an alternative to whey or outside of weight training, as described in the guide on protein powder without weight training.

Plant protein and physical activity

Protein contributes to an increase in muscle mass, whether it comes from plants or animals¹. The International Society of Sports Nutrition (ISSN) position stand on protein and exercise gives three useful benchmarks⁶:

• 1.4 to 2.0 g of protein per kilo of body weight per day for most athletes;
• servings of around 20 to 40 g, spread every 3 to 4 hours;
• 700 to 3,000 mg of leucine per serving, with the full set of essential amino acids.

A 12-week study published in 2015 by Babault and colleagues⁷ found no significant difference between pea protein and whey on biceps thickness gains, for an equivalent intake and training programme. What matters, for a plant source as much as for an animal one, is the total daily intake and a complete essential amino acid profile at each serving. To place protein among other supplements for exercise, the sports nutrition guide reviews the supplements that help, and the creatine fact sheet details another benchmark for weight training, the 3 g a day dose.

Plant protein versus animal protein: the differences

Both families provide useful protein: what matters is the variety of sources and the total daily intake, not origin alone.

Common beliefs about plant protein

Precautions for use

• Soy and phytoestrogens: as a precaution, ANSES recommends that pregnant or breastfeeding women and young children limit foods and supplements rich in phytoestrogens, including soy⁸.
• Food allergies: soy is one of the allergens subject to mandatory labelling; always check the ingredient list if you are allergic.
• Kidney disease: protein restriction may be necessary; no change without medical advice.
• Variety of sources: a diet based on a single plant source increases the risk of not covering all essential amino acids.

Key points

• Protein contributes to an increase in muscle mass and to the maintenance of normal bones, whatever its origin.
• Reference benchmark: 0.83 g of protein per kilo of body weight per day for adults (EFSA), 1.4 to 2.0 g for most athletes (ISSN).
• Legumes, soy, whole grains and pseudo-cereals, nuts and seeds are the best food sources.
• Varying sources across the day is enough to cover all 9 essential amino acids, with no need to combine them at the same meal.

Frequently asked questions

Sources