Complete Protein Sources: A Practical Guide to All 9 Essential Amino Acids

National Wellness Index Resources · Last updated August 2026

Protein is built from 20 amino acids. The body can produce 11 of them on its own, but the other nine — the "essential" amino acids — have to come from food. A food that supplies all nine in one go is called a complete protein. Foods that are missing or low in one or more are called incomplete proteins.

Animal-based complete proteins

Every major animal protein source is naturally complete: meat, poultry, fish, eggs and dairy all supply the full set of essential amino acids. Eggs and Greek yoghurt are particularly convenient everyday options — compact, versatile, and easy to add to most meals.

Plant-based complete proteins

These are especially useful for vegetarians and vegans who want a complete protein without needing to combine multiple foods deliberately.

What about incomplete proteins?

Foods like beans, lentils, chickpeas, nuts, oats, brown rice and chia seeds are rich in protein but are individually missing or low in at least one essential amino acid. That doesn't make them lesser foods — they're still valuable sources of protein and fibre. The outdated idea that you must combine complementary proteins (like rice and beans) in the same meal has been dropped by most current dietetic guidance. What actually matters is getting a reasonable variety of protein sources across the day, not necessarily on the same plate.

Practical everyday combinations

• Greek yoghurt with oats and fruit — a complete protein plus fibre
• Tofu or tempeh stir-fry with rice and vegetables
• Eggs on wholegrain toast with beans
• Lentil soup with a side of bread through the day, alongside another protein source at a different meal
• Hummus (chickpeas) with wholegrain pitta and a handful of nuts as a snack