Are Eggs Better Than Chicken For Protein Quality?

October 14, 2025 •

4 min read

By convention, the World Health Organization (WHO) once used whole egg protein as the gold standard for measuring protein quality. This has led many to wonder if, even with a lower protein-by-weight ratio, eggs truly are better than chicken for protein quality. While both are high-quality, complete protein sources, a closer look reveals key distinctions in their nutritional value and how the body utilizes their protein.

Quick Summary

This article explores the protein quality of eggs and chicken, comparing protein amounts, amino acid compositions, and how well the body uses them. Find out the advantages of chicken's high protein content and the superior digestibility and nutrient content of eggs to determine which is best for you.

Key Points

Both are complete proteins: Both eggs and chicken contain all nine essential amino acids needed by the human body.
Chicken has higher protein density: Skinless chicken breast offers significantly more protein per 100 grams than eggs, making it ideal for high-protein diets.
Eggs have slightly higher digestibility: Cooked eggs have a marginally superior protein digestibility rate compared to chicken, meaning the body absorbs and uses their amino acids a little more efficiently.
Eggs are more nutrient-dense overall: Eggs provide a wider spectrum of micronutrients, including choline, vitamin D, and antioxidants, compared to chicken breast.
Choice depends on goals: Opt for chicken for concentrated, lean protein. Choose eggs for a balance of high-quality protein, diverse vitamins, and healthy fats.
Balance is key: Incorporating both eggs and chicken into your diet provides a comprehensive range of nutrients and protein benefits.

Understanding Protein Quality

Protein quality is not just about the total grams of protein in a food. It's a measure of how well the body can absorb and utilize that protein. This is determined by two main factors: the amino acid profile and bioavailability. Both eggs and chicken contain all nine essential amino acids, making them 'complete proteins'. However, their scores for digestibility and protein concentration differ.

Protein Quality Metrics: PDCAAS and Bioavailability

The Protein Digestibility Corrected Amino Acid Score (PDCAAS) and the Digestible Indispensable Amino Acid Score (DIAAS) are standard metrics used to evaluate protein quality. While specific PDCAAS values vary, it is widely acknowledged that animal proteins like eggs and chicken typically score very high, often 1.0 or close to it, indicating they provide 100% or more of the essential amino acids needed by the body after digestion. Bioavailability refers to the proportion of a nutrient that is absorbed from the diet and used for normal body function. Studies have shown slight differences in digestibility rates, with eggs often showing a slightly higher rate.

Comparing the Protein Profiles: Eggs vs. Chicken

Eggs

Eggs are often considered a nutritional powerhouse, and for good reason.

Complete Amino Acid Profile: One large egg (around 50g) contains approximately 6-7 grams of high-quality protein with all essential amino acids.
High Bioavailability: Cooked egg protein has an exceptional digestibility rate, with studies showing around 91% of its protein is absorbed and utilized by the body. This is due to the process of heat denaturing the proteins, making them more accessible to digestive enzymes.
Nutrient-Dense: Eggs also provide a wealth of other essential nutrients, including choline for brain health, antioxidants like lutein and zeaxanthin for eye health, and vitamins like D and B12. The yolk contains nearly half the protein, along with the fat-soluble vitamins.
Versatility and Cost: Eggs are extremely versatile, affordable, and easy to prepare, making them a convenient protein source for many diets.

Chicken

Chicken, particularly lean chicken breast, is a staple in many fitness and health-focused diets.

High Protein Density: A 100-gram serving of cooked, skinless chicken breast provides a significantly higher protein content—around 31 grams—compared to a similar serving of eggs. This makes it a more concentrated source of protein by weight.
Lean Source: Skinless chicken breast is very low in fat, with about 80% of its calories coming from protein. This is ideal for those focused on high protein, low-calorie intake for weight loss or muscle building.
Amino Acid Content: Chicken breast also contains all essential amino acids, making it a high-quality protein. It's particularly high in certain essential amino acids like threonine, lysine, and histidine.
Bioavailability: Chicken protein is also highly digestible, though some studies show it is slightly less than eggs, with digestibility rates often cited in the 90-94% range.

Comparison Table: Eggs vs. Chicken (per 100g cooked portion)


Feature	Large Eggs (approx. 2)	Skinless Chicken Breast
Protein Content	~12.6g	~31g
Calories	~155 kcal	~165 kcal
Total Fat	~11g	~3.6g
Protein Density	Lower per gram	Higher per gram
Bioavailability	Very high (~91%)	Very high (~92%)
Amino Acids	Complete profile; high standard	Complete profile; high concentration
Micronutrients	Rich in choline, vitamins D, B12, and antioxidants	Rich in B vitamins (especially Niacin), potassium, and phosphorus

Which is Better for You? Making the Choice

Deciding which is 'better' depends on your specific nutritional goals. Neither is definitively superior in all aspects. The quality of their protein is very similar, with both providing a complete amino acid profile and excellent bioavailability. However, the key differences lie in their concentration and overall nutrient package. If your primary goal is to maximize protein intake while minimizing calories and fat, chicken breast is the clear winner due to its higher protein density. This makes it a preferred choice for bodybuilders or those on a weight loss diet. Conversely, if you prioritize nutrient diversity and a slightly higher bioavailability, eggs are an outstanding option. Eggs provide essential fats and a wider array of vitamins and minerals like choline and vitamin D, which are less concentrated in chicken breast. A balanced approach, incorporating both, can provide the benefits of both worlds and add variety to your diet. For further reading on nutritional comparisons, an authoritative source like the USDA's FoodData Central is a reliable resource.

Conclusion

Ultimately, the question of whether eggs are better than chicken for protein quality has a nuanced answer. While eggs are technically the gold standard for bioavailability and offer a more diverse nutrient profile in a compact package, chicken breast offers a higher concentration of protein with less fat per serving. Both are excellent sources of high-quality, complete protein, and the best choice for you will depend on your specific dietary needs, fitness goals, and preferences. For maximizing lean protein intake, chicken breast comes out on top, but for a more holistic nutrient-dense option with slightly superior digestibility, eggs are hard to beat. Incorporating both into a balanced diet is the most effective strategy for optimal nutrition.

Frequently Asked Questions

The protein quality of both eggs and chicken is exceptionally high because they are both complete proteins containing all essential amino acids. Historically, egg protein was the standard for measuring protein quality, and it has a slightly higher bioavailability, meaning your body digests and utilizes it a bit more efficiently.

Chicken breast provides significantly more protein per serving. A 100-gram cooked, skinless chicken breast offers around 31 grams of protein, whereas two large eggs, which weigh approximately 100 grams, contain about 12.6 grams of protein.

Eggs are considered the 'gold standard' due to their superior digestibility and a complete, well-balanced amino acid profile that matches the body's needs very closely. The World Health Organization (WHO) has used egg protein as a reference standard for evaluating other protein sources.

While both are excellent for muscle building, chicken breast is often preferred for its higher protein density per calorie. This allows you to consume more protein without significantly increasing your fat or calorie intake, which can be advantageous for muscle growth, particularly for those on a strict macro diet.

Eggs are generally more nutrient-dense overall. While chicken breast is richer in certain vitamins like Niacin, eggs contain a wider array of nutrients including choline, vitamin D, and antioxidants (lutein and zeaxanthin) that are less prevalent in chicken breast.

Cooking actually improves the digestibility and bioavailability of protein in both eggs and chicken. For eggs, heat denatures the proteins, making them more easily accessible to digestive enzymes. Cooked egg protein has significantly higher bioavailability than raw egg protein.

Yes, incorporating both eggs and chicken into a balanced diet is an excellent strategy. This approach allows you to benefit from the distinct nutritional profiles of each, including the high protein concentration of chicken and the micronutrient richness of eggs, ensuring a well-rounded intake.