Can you get all 9 essential amino acids from plants? The complete guide

October 29, 2025 •

4 min read

For decades, many believed plant proteins were nutritionally inferior because they were 'incomplete'. In reality, a well-planned, plant-based diet can absolutely provide all nine essential amino acids needed for optimal health. This guide will explain how to easily achieve this.

Quick Summary

It is a myth that plant proteins are incomplete; with a varied diet, you can obtain all nine essential amino acids from plant-based sources. Your body effectively pools amino acids from different foods eaten throughout the day to meet its protein needs.

Key Points

Dispelling the Myth: The idea that vegans must combine specific proteins at every meal is an outdated myth. The body pools amino acids throughout the day.
Complete Plant Proteins: Several single plant foods, including soy (tofu, tempeh), quinoa, buckwheat, and hemp seeds, contain all nine essential amino acids.
Power of Variety: Eating a varied diet of legumes, grains, nuts, and seeds naturally ensures you get all essential amino acids over the course of the day.
Complementary Combos: Pairing legumes and grains (like rice and beans) or nuts and legumes helps fill any minor amino acid gaps effortlessly.
Balanced Approach: Focusing on whole foods, variety, and overall calorie intake is more important than stressing over protein completeness in every single bite.
Nutrient-Dense Sources: Plant-based protein sources are also packed with fiber, vitamins, and minerals, offering additional health benefits beyond just protein.

The Myth of the 'Incomplete' Protein

For many years, the idea that plant proteins were 'incomplete' and that vegans or vegetarians needed to meticulously combine specific plant foods at each meal to create a 'complete' protein was widely circulated. This idea was popularized in Frances Moore Lappé's 1971 book, Diet for a Small Planet, though the author has since recanted the statement. This persistent misconception led to unnecessary stress and confusion for those following a plant-based diet. The truth is far simpler and more flexible.

What are essential amino acids?

Amino acids are the building blocks of protein, which our bodies use for vital functions like building muscle, regulating the immune system, and carrying oxygen. There are 20 total amino acids, 11 of which the body can produce on its own. The remaining nine, however, are considered 'essential' because they must be obtained through the diet. These nine are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. All 20 amino acids, including all nine essential ones, are present in every plant, but the amounts vary. This variation is the root of the 'incomplete' protein myth. However, your body is much smarter than once believed; it maintains a pool of amino acids throughout the day from all the foods you consume, not just what's in a single meal.

Plant-Based Complete Protein Sources

Fortunately, several single plant foods are considered 'complete' proteins, containing all nine essential amino acids in sufficient amounts. Including these foods is an easy way to meet your amino acid needs.

Soy Products: Tofu, tempeh, and edamame are excellent complete protein sources derived from soybeans. They are incredibly versatile and can be incorporated into countless recipes.
Quinoa: This ancient grain (technically a pseudocereal) is a nutritional powerhouse and one of the few complete proteins in the plant kingdom. It's a great base for salads and bowls.
Buckwheat: Another gluten-free pseudocereal, buckwheat provides a balanced amino acid profile, with a notable amount of lysine. It can be used in porridge, pancakes, or as a rice substitute.
Hemp Seeds: These little seeds are a nutritional powerhouse, providing a complete protein as well as essential fatty acids. They can be sprinkled on salads, yogurt, or blended into smoothies.
Chia Seeds: Similar to hemp seeds, chia seeds also contain all nine essential amino acids, along with plenty of fiber and omega-3s. They are perfect for puddings or as a thickening agent.
Pistachios: Among nuts, pistachios offer a complete protein profile, making them a fantastic snack option.

The Power of Variety: Complementary Proteins

Beyond single complete sources, you can easily obtain all essential amino acids by eating a variety of plant foods throughout the day. The old rule of pairing specific proteins in a single meal is unnecessary; your body will utilize its amino acid stores to fill any gaps.

How do complementary proteins work?

Legumes like beans, lentils, and chickpeas are rich in most essential amino acids, but often lower in methionine. Grains, nuts, and seeds are typically good sources of methionine but may be lower in lysine. By eating a variety of these foods, you ensure you get sufficient amounts of all nine essential amino acids.

Classic complementary protein combinations:

Rice and beans or lentils
Hummus and whole-grain pita bread
Peanut butter on whole-wheat bread
Tofu or tempeh with wild rice
Lentil soup with a side of multigrain bread

Plant Protein Comparison Table


Food Source	Protein (per serving)	Completeness	Key Amino Acid Notes
Tofu (1 cup)	~20g	Complete	Excellent source of all EAAs, very high protein
Lentils (1 cup cooked)	~18g	Nearly Complete	High in lysine, lower in methionine
Quinoa (1 cup cooked)	~8g	Complete	Contains all 9 EAAs in sufficient amounts
Chickpeas (1 cup cooked)	~15g	Nearly Complete	Good source of lysine, complement with grains
Hemp Seeds (3 tbsp)	~10g	Complete	Easily digestible source of all EAAs
Brown Rice (1 cup cooked)	~5g	Nearly Complete	Good methionine source, low in lysine
Almonds (1 oz)	~6g	Nearly Complete	Versatile, pairs well with other proteins
Buckwheat (1/2 cup)	~3g	Complete	Good source of lysine for a grain

Creating a Balanced Plant-Based Diet

To ensure you meet all your essential amino acid needs, focus on three key strategies: variety, frequency, and quantity. By varying your protein sources throughout the day, you can naturally create a complete amino acid profile without worrying about combining specific foods in every single meal. Prioritize eating a wide range of legumes, whole grains, nuts, and seeds. A good rule of thumb is to 'eat the rainbow,' as variety ensures a broad spectrum of nutrients and amino acids. To further boost your intake, consider plant-based protein powders or fortified plant milks, which often provide a convenient, complete protein source. For those with specific dietary requirements, a registered dietitian can provide personalized guidance. The old worries about plant protein are outdated, and a balanced, plant-centric diet can easily provide all the building blocks your body needs.

Conclusion

In conclusion, the answer to the question, Can you get all 9 essential amino acids from plants? is a definitive yes. The long-standing myth of 'incomplete' plant protein has been debunked by modern nutritional science. Many plant foods, such as soy, quinoa, and hemp seeds, are complete proteins in their own right. For foods that may be lower in certain essential amino acids, simply eating a variety of different plant-based protein sources throughout the day is sufficient, as the body can pool amino acids from different meals. By embracing variety and whole foods like legumes, grains, nuts, and seeds, anyone can easily build a protein-rich, balanced, and healthy plant-based diet.

Medical News Today offers further insights into the history and science behind essential amino acid requirements. This demonstrates that for a well-planned plant-based diet, a lack of essential amino acids is not a concern, and that relying on animal protein for completeness is a misconception.

Frequently Asked Questions

A handful of plant foods are complete proteins, meaning they contain all nine essential amino acids in sufficient amounts. These include soy products (tofu, tempeh, edamame), quinoa, buckwheat, hemp seeds, chia seeds, and pistachios.

No, this is an outdated recommendation based on a long-debunked myth. Your body is capable of storing and recycling amino acids from different meals throughout the day. A varied diet is all that is needed to ensure you get all essential amino acids.

Complementary proteins are pairs of plant foods that, when combined, provide a complete set of essential amino acids. For example, legumes are often lower in methionine, while grains are lower in lysine. Eating them together or at different times of the day ensures you receive a full amino acid profile.

Yes, many successful athletes and bodybuilders follow plant-based diets. As long as adequate calories and a variety of protein sources are consumed, it is entirely possible to meet protein needs and build muscle on a plant-based diet.

While there can be differences in the bioavailability and specific amino acid ratios, a well-planned plant-based diet provides all the necessary amino acids for optimal health. Plant-based proteins also come with added fiber, vitamins, and minerals that animal proteins lack.

Focus on including a variety of legumes, whole grains, nuts, and seeds in your meals. Snacks like a handful of almonds or a smoothie with hemp seeds are also easy ways to boost your protein intake.

Protein deficiency is very rare in developed countries and is almost unheard of for vegans who eat a balanced diet with sufficient calories. Most concerns stem from misconceptions rather than actual dietary shortfalls.