What Is a Complete Protein? The Building Blocks for Your Body
A complete protein is a food that contains an adequate proportion of all nine essential amino acids your body cannot make on its own and must obtain from your diet.
At a glance
- Term
- Complete Protein
- What it is
- Dietary protein classification
- Section
- Food and nutrition
- Also called
- Whole protein
- In one line
- It’s a food that gives you all the essential protein building blocks your body can’t make on its own.
What Complete Protein means
Proteins are made up of chemical building blocks called amino acids. Your body uses about 20 different amino acids to build tissues, make enzymes, and perform other critical functions. Of these, nine are considered ‘essential amino acids’ because your body cannot produce them. You must get them from the food you eat. A complete protein is a food source that provides all nine of these essential amino acids in roughly the amounts needed by the human body. This is why they are often referred to as high-quality proteins.
Animal-based foods are the most commonly known sources of complete protein. This includes meat, poultry, fish, eggs, and dairy products like milk, yogurt, and cheese. However, they are not the only sources. A number of plant-based foods also qualify as complete proteins. Soy products, such as tofu, tempeh, and edamame, are complete proteins, as are quinoa, buckwheat, hemp seeds, and chia seeds. This means that complete protein sources are available for various dietary patterns and preferences.
Many plant foods, such as beans, lentils, nuts, and whole grains, are considered ‘incomplete’ proteins. This means they are low in one or more of the essential amino acids. For example, beans are often low in the amino acid methionine, while grains can be low in lysine. However, by eating a variety of plant protein sources, you can easily get all the amino acids you need. This concept is known as protein complementation. Classic food pairings like rice and beans or hummus and pita bread are examples of this.
Getting a sufficient supply of all essential amino acids is necessary for your body to repair cells and make new ones. While thinking in terms of ‘complete proteins’ can be a helpful shorthand, the overall focus should be on eating a varied diet. The idea that you must combine incomplete proteins at every single meal has been revised. Your body maintains a pool of amino acids, so as long as you consume a variety of protein sources throughout the day, you can meet your needs.
What public guidance says
The National Academies’ recommended dietary allowance for protein for adults is 0.8 grams per kilogram of body weight per day.
How to Get Complete Proteins
- Include animal sources like meat, fish, eggs, and dairy in your diet, if you choose to eat them.
- Incorporate complete plant-based proteins such as quinoa, tofu, tempeh, and edamame into your meals.
- Eat a variety of plant foods throughout the day, such as legumes, nuts, seeds, and grains, to ensure you get a full range of amino acids.
- Focus on your overall daily intake rather than trying to perfectly combine proteins at every single meal.
- Read nutrition labels on packaged foods to understand their protein content and sources.
Complete Protein vs. similar terms
| Compared with | How Complete Protein differs | What the other term means |
|---|---|---|
| Essential Amino Acids | A complete protein is a food source that contains all nine essential amino acids. | Essential amino acids are the individual protein building blocks that the body cannot produce on its own. |
Common misconceptions
- Myth: You can only get complete protein from meat and other animal products. Several plant-based foods are complete proteins, including soy, quinoa, and buckwheat. You can also get all essential amino acids by eating a variety of plant foods.
- Myth: You have to combine incomplete proteins at the same meal to get the benefit. Your body can draw on amino acids from foods eaten throughout the day. Focusing on dietary variety daily is sufficient, without needing to combine specific foods in one sitting.
- Myth: A food is not healthy unless it’s a complete protein. Many nutritious foods like beans, lentils, and nuts are incomplete proteins but are excellent sources of fiber, vitamins, and minerals, and contribute to overall protein needs.
Related terms
When to bring in a professional
While protein needs can generally be met through diet, it’s a good idea to speak with a registered dietitian or your doctor in certain situations.
- If you are planning to switch to a vegetarian or vegan diet and want to ensure your nutritional needs are met.
- If you have a medical condition, such as kidney disease, that requires careful management of protein intake.
- If you are an athlete with specific performance goals and are unsure about your protein requirements.
- If you are experiencing unexplained fatigue, hair loss, or poor recovery from exercise, which could be related to your diet.
How this entry was made: drafted with AI assistance from general, widely published definitions, checked in a separate verification pass for invented numbers and claims, and edited by the Millennials Wellness editors. General information only, not medical, financial or legal advice. Last checked October 2026. Our ground rules · Back to the glossary