Why are Chickpeas Not a Complete Protein?

October 31, 2025 •

3 min read

While a single cup of cooked chickpeas provides a respectable 15 grams of protein, like most legumes, chickpeas are not a complete protein. This is due to a deficiency in one or more of the nine essential amino acids that our bodies cannot produce, and must obtain from our diets.

Quick Summary

Chickpeas are an incomplete protein because they are low in the essential sulfur-containing amino acid, methionine. This is common among legumes, which can be combined with grains to provide all essential amino acids for a balanced vegan diet.

Key Points

Incomplete Protein: Chickpeas lack the full spectrum of essential amino acids required for a 'complete protein' classification.
Limiting Amino Acid: The primary reason chickpeas are an incomplete protein is their low content of the essential amino acid methionine.
Complementary Pairing: Pairing chickpeas with grains (like rice or wheat) or seeds (like sesame seeds in tahini) creates a complete protein profile.
Daily Intake Matters: The body can combine amino acids from different foods consumed over the course of a day, so complementary foods don't need to be eaten at the same time.
Beyond Protein: Chickpeas offer significant nutritional benefits beyond protein, including high fiber, complex carbohydrates, and essential minerals.

Understanding the 'Complete' Protein Concept

Protein is a crucial macronutrient made of amino acids, with nine being 'essential' as the body cannot produce them. A 'complete protein' source contains all nine essential amino acids in sufficient amounts. Animal products are typically complete proteins, while most individual plant sources, including chickpeas, are considered 'incomplete'.

The Limiting Amino Acid in Chickpeas

Chickpeas are not a complete protein primarily because they are low in the essential sulfur-containing amino acid methionine, although they are rich in others like lysine. Methionine is the 'limiting amino acid,' meaning it's the one in the lowest proportion relative to our needs. This is characteristic of legumes but easily managed by combining foods.

The Power of Complementary Proteins

Modern nutrition confirms that the body can combine amino acids from different foods eaten throughout the day. This makes 'complementary proteins' an effective strategy for plant-based diets. Pairing chickpeas with foods high in methionine compensates for their deficiency.

Classic Complementary Protein Combinations

Chickpeas and Grains: Grains like rice and wheat are high in methionine. Combining chickpeas with rice or having hummus on whole-wheat bread provides a complete protein.
Chickpeas and Seeds: Sesame seeds, found in tahini, are rich in methionine. This is why hummus (chickpeas and tahini) is a complete protein.
Chickpeas and Nuts: Adding nuts to chickpea dishes can also help balance amino acid intake over the day.

Comparison of Protein Sources: Chickpeas vs. Complete Proteins


Feature	Chickpeas (Incomplete Protein)	Quinoa (Complete Protein)	Beef (Complete Protein)
Completeness	No (low in methionine)	Yes (all essential amino acids)	Yes (all essential amino acids)
Limiting Amino Acid	Methionine	None	None
Dietary Pairing	Best when paired with grains or seeds	Can be eaten alone for a complete protein	Can be eaten alone for a complete protein
Typical Lysine Content	High	Sufficient	Sufficient
Typical Methionine Content	Low	Sufficient	Sufficient
Fiber Content	High	High	None
Saturated Fat & Cholesterol	Low fat, no cholesterol	Low fat, no cholesterol	Often high fat, contains cholesterol

The Myth of 'Protein Combining'

The outdated idea that complete proteins are needed at every meal is incorrect. The body uses amino acids from various foods eaten throughout the day. Consuming a diverse range of protein sources daily ensures the body gets all essential amino acids. This simplifies meeting protein needs on a vegan or vegetarian diet, as different plant proteins can complement each other over the day.

The Nutritional Benefits of Chickpeas

Beyond protein, chickpeas offer significant health benefits. They are high in fiber, supporting digestion and weight management, and provide complex carbohydrates for energy. They are also rich in folate, iron, and phosphorus. Growing chickpeas is also more environmentally sustainable than many animal proteins. Their versatility makes them a popular ingredient globally. For detailed nutritional information, refer to scientific reviews, such as those published by the British Journal of Nutrition.

Conclusion

Chickpeas are incomplete proteins due to low methionine content. However, this is easily addressed by consuming complementary foods like grains and seeds throughout the day, as the body effectively combines amino acids. Chickpeas are highly nutritious, offering fiber, vitamins, and minerals, making them a valuable part of a balanced diet. A varied plant-based diet is key to obtaining all essential amino acids for optimal health.

Frequently Asked Questions

A complete protein is a food source that contains all nine of the essential amino acids that the human body cannot produce on its own.

Chickpeas are deficient in the sulfur-containing essential amino acid, methionine.

No, you do not. The body maintains a pool of amino acids, so combining different plant-based proteins throughout the day is sufficient to meet your needs.

Yes, traditional hummus is a complete protein because it combines chickpeas with tahini (sesame seeds), which supplies the missing methionine.

Some plant-based foods that are naturally complete proteins include soy products (tofu, tempeh, edamame), quinoa, hemp seeds, and nutritional yeast.

A simple way is to serve a chickpea curry with rice or have a sandwich with hummus on whole-wheat bread.

Yes, chickpeas are a valuable source of protein for plant-based diets, but it's important to consume them as part of a varied diet that includes grains and seeds to ensure all essential amino acids are acquired.