Understanding What Are Good Sources of High Quality Complete Protein

January 11, 2026 •

4 min read

According to research, proteins are considered the building blocks of life, playing a crucial role in nearly every biological process. A high-quality complete protein is one that contains all nine essential amino acids that our bodies cannot produce on their own. Understanding what are good sources of high quality complete protein is essential for maintaining and repairing tissues, supporting immune function, and building muscle.

Quick Summary

This guide outlines the best sources of high-quality complete protein, detailing options from both animal and plant-based foods. It clarifies what constitutes a complete protein, highlights specific examples, and explains how vegans and vegetarians can meet their needs through proper food pairing.

Key Points

Essential Amino Acids: High-quality complete proteins contain all nine essential amino acids that the body cannot produce on its own.
Animal Sources: Meat, poultry, fish, eggs, and dairy are all reliable sources of complete protein.
Plant-Based Options: Quinoa, soy products (tofu, tempeh), buckwheat, and hempseeds are notable plant-based complete protein sources.
Combining Proteins: Vegans and vegetarians can get all essential amino acids by eating a variety of incomplete plant proteins throughout the day (e.g., rice and beans), not necessarily in the same meal.
Balanced Diet: Opting for a mix of high-quality protein sources ensures you also get a wide range of other important nutrients like vitamins, minerals, and fiber.

What is a Complete Protein?

Proteins are large, complex molecules essential for body function, composed of smaller units called amino acids. Of the 20 amino acids, nine are 'essential' because the human body cannot produce them and must obtain them through diet. A complete protein source is a food that contains adequate proportions of all these nine essential amino acids. These essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The biological value and digestibility of a protein determine its overall quality, with higher quality proteins being more readily used by the body.

Animal-Based Sources of High-Quality Complete Protein

Animal products are the most common and direct sources of complete protein. This is because their amino acid profile closely matches the needs of the human body. These sources also tend to have a higher overall protein content per serving compared to many plant-based alternatives.

Meat and Poultry: Lean cuts of beef, pork, turkey, and chicken are excellent sources. Skinless chicken breast, for instance, provides a high concentration of protein with relatively low fat.
Fish and Seafood: Salmon, tuna, cod, and other types of fish are not only rich in complete protein but also provide beneficial omega-3 fatty acids.
Eggs: Often called the 'perfect protein' due to their superior amino acid profile, eggs are a versatile and affordable option.
Dairy Products: Milk, yogurt (especially Greek yogurt), and cheese are excellent and widely available sources of complete protein. They are also rich in calcium and other important nutrients.

Plant-Based Sources of High-Quality Complete Protein

While many plant-based foods are considered incomplete proteins, lacking sufficient amounts of one or more essential amino acids, several are complete on their own. It's also possible to combine different incomplete plant proteins to create a complete profile throughout the day.

Quinoa: This pseudocereal is a standout among grains, containing all nine essential amino acids.
Soy Products: Tofu, tempeh, and edamame are all derived from soybeans and provide a complete protein profile, making them staples in vegetarian and vegan diets.
Buckwheat: Another pseudocereal, buckwheat is a versatile ingredient for pancakes, noodles, and porridges that offers a full range of essential amino acids.
Hempseed: These seeds are an excellent source of complete protein and can be added to smoothies, salads, and baked goods.
Chia Seeds: Much like hempseed, chia seeds offer a complete protein profile, along with high levels of fiber and omega-3s.
Spirulina: This blue-green algae is a potent complete protein source, often consumed as a powder in smoothies or supplements.
Ezekiel Bread: Made from sprouted grains and legumes, this bread contains a complete protein profile.

Combining Incomplete Proteins for a Complete Profile

For those relying on plant-based sources, combining incomplete proteins is an effective strategy to ensure all essential amino acids are consumed. The historical belief that combinations must happen in the same meal has been debunked; what is important is consuming a variety of sources throughout the day.

Some classic examples of complementary protein combinations include:

Grains with Legumes: The classic pairing of rice and beans, or chickpeas and rice, effectively covers all essential amino acids.
Nuts/Seeds with Legumes: A salad with chickpeas and sunflower seeds or a meal featuring tofu with cashews creates a complete protein.
Hummus and Whole Wheat Pita: The combination of ground chickpeas and wheat provides the full spectrum of essential amino acids.

Comparison of Complete Protein Sources

To help illustrate the differences and benefits, here is a comparison table of several common complete protein sources based on typical serving sizes and nutrient profiles.


Source	Category	Typical Serving Size	Protein (g)	Additional Benefits
Chicken Breast	Animal	100g (cooked, skinless)	~27	High in B vitamins like B6 and Niacin.
Salmon	Animal	100g (cooked)	~25	Rich in omega-3 fatty acids, crucial for heart and brain health.
Greek Yogurt	Dairy	100g	~10	High in calcium and probiotics, good for gut health.
Eggs	Animal	1 large egg	~6	Excellent source of choline and vitamins A, D, E.
Tofu	Plant	100g	~8	Versatile, good source of calcium, and iron. Lower in calories than some animal sources.
Quinoa	Plant	1 cup (cooked)	~8	Contains fiber, magnesium, and manganese.

Considerations for Choosing Protein Sources

When selecting complete protein sources, it's important to consider factors beyond just the amino acid profile. Whole foods, whether animal or plant-based, offer a nutritional package that includes vitamins, minerals, fiber, and healthy fats.

For example, while animal proteins provide iron and zinc, many plant proteins offer fiber and antioxidants. For those on a vegan or vegetarian diet, focusing on variety throughout the day ensures a balanced amino acid intake without needing to meticulously combine foods in each meal. Athletes and older adults may have higher protein needs and should pay particular attention to ensuring they meet their daily requirements to support muscle synthesis and prevent loss.

Ultimately, a balanced diet that includes a variety of high-quality complete protein sources—or complementary incomplete proteins—is the best approach for optimal health. There are many delicious and nutritious options available to suit all dietary preferences.

Conclusion

High-quality complete protein sources are vital for numerous bodily functions, from muscle repair to immune support. Whether you get your protein from animal-based foods like meat, fish, eggs, and dairy, or from plant-based options such as quinoa, soy, and hempseed, the key is to ensure you consume all nine essential amino acids. Plant-based diets can easily meet these needs by combining different protein sources throughout the day. By prioritizing a variety of complete or complementary proteins, you can support your body's health and performance effectively. For further reading and dietary information, consult resources like the Harvard T.H. Chan School of Public Health's detailed guide on protein, which offers comprehensive insights into balancing protein intake from different sources.

Frequently Asked Questions

A complete protein source contains all nine essential amino acids that the body requires from food, while an incomplete protein source lacks or has insufficient amounts of one or more of these amino acids.

Yes, it is entirely possible to get enough complete protein on a plant-based diet. By eating a variety of plant-based foods throughout the day, you can ensure your body receives all nine essential amino acids.

No, the need to combine complementary proteins in a single meal is a common myth. Your body can effectively combine amino acids from different foods consumed throughout the day to form complete proteins.

Animal proteins are typically considered higher quality because their amino acid profile more closely matches human needs and they are more easily digestible. However, certain plant proteins like soy and quinoa are also complete and highly beneficial.

For muscle building, excellent choices include lean animal proteins like chicken, fish, and eggs, as well as plant-based options like soy and quinoa. High-protein dairy products like Greek yogurt are also very effective.

Many protein powders, especially those derived from whey or soy, are excellent sources of complete protein. They can be a convenient way to boost protein intake, though whole food sources offer additional micronutrients.

You can add more complete protein by incorporating eggs into your breakfast, adding Greek yogurt or cottage cheese as a snack, and including a mix of lean meats, fish, tofu, or quinoa in your main meals. For plant-based diets, mixing legumes and grains is effective.