How much protein per 100g of breast? A comprehensive guide

December 6, 2025 •

3 min read

A skinless, cooked chicken breast provides a concentrated 31 grams of protein per 100g, while mature human breast milk contains around 1.2 grams of protein per 100g (or mL). The answer to "how much protein per 100g of breast?" depends entirely on the specific context, as the term can refer to distinct and nutritionally different sources.

Quick Summary

This article clarifies the significant protein differences in 100g servings of chicken breast and human breast milk, detailing nutritional values, the impact of preparation and lactation stage, and comparison with other sources.

Key Points

Chicken Breast Protein: A 100g serving of cooked, skinless chicken breast provides approximately 31 grams of high-quality protein.
Human Breast Milk Protein: Mature human breast milk contains a lower protein concentration, about 1.2 grams per 100g (or mL), which is perfectly adapted for infant digestion and development.
Raw vs. Cooked: Cooking chicken breast concentrates the protein per gram, as water is cooked out. Raw chicken breast has a lower protein count per 100g than cooked.
Lactation Stage Matters: The protein content of human milk is highest in colostrum and decreases as the milk matures over the first few weeks of lactation.
Context is Key: The term "breast" has two very different nutritional meanings, referring either to a food source (chicken) or a dynamic bodily fluid (human milk).
Leanest Option: Skinless, boneless chicken breast is one of the leanest protein sources available, with minimal fat.
Bioactive Benefits: Human breast milk contains numerous bioactive factors and immune components that are crucial for infant health, in addition to its protein content.

Clarifying the Context: A Tale of Two Breasts

When searching for the protein content of "breast," you may be referring to two very different sources: chicken breast, a common food item, or human breast milk, a vital source of infant nutrition. The nutritional profile of each is vastly different, and understanding the distinction is crucial for accurate dietary information. This guide will explore both in detail, providing specific protein metrics and a broader nutritional perspective for each.

Protein in Chicken Breast: A Fitness Staple

Chicken breast is renowned as a high-protein, low-fat source of lean meat. The protein content varies based on whether the meat is raw or cooked.

Raw vs. Cooked Chicken Breast

Cooking concentrates protein by reducing water content.

Raw, skinless chicken breast: Approximately 22-23 grams of protein per 100g.
Cooked, skinless chicken breast: Up to 31 grams of protein per 100g.

Cooking Method and Preparation

Cooking methods don't destroy protein but affect its concentration. Adding skin, sauces, or oils increases calories and fat without changing protein.

Protein in Human Breast Milk: Infant Nutrition

Human breast milk composition, including protein, changes over time to meet infant needs. Its protein level is lower than chicken breast but ideal for infant development.

Protein Variation by Lactation Stage

Protein concentration varies:

Colostrum (first few days): Highest protein (1.4-1.6 g/100mL), rich in immune factors.
Mature Milk (after two weeks): Stabilizes at 0.8-1.2 g/100mL.

Foremilk vs. Hindmilk

Protein levels are generally consistent within a feeding, unlike fat content which increases.

Protein in Human vs. Cow Milk

Human milk protein has more easily digestible whey than cow's milk and is perfectly formulated for infants, unlike higher-protein cow's milk.

Comparison of Protein Sources


Nutrient	Cooked Chicken Breast (per 100g)	Mature Human Breast Milk (per 100g)
Protein	~31g	~1.2g
Calories	~165 kcal	~70 kcal
Fat	~3.6g	~4g
Carbohydrates	0g	~7g (as lactose)
Main Function	Muscle building and repair	Infant growth and immunity

Beyond Protein: Nutritional Differences

Chicken breast provides all essential amino acids and is rich in B vitamins, phosphorus, and selenium. Human breast milk contains bioactive factors like lactoferrin and secretory IgA, lactose for energy, and fats for neurological development, supporting infant growth, immunity, and brain function.

Preparing and Sourcing Chicken Breast

Use lean cooking methods like grilling or baking. Skinless, boneless chicken is leanest. Avoid processed products.

The Importance of Human Milk Composition

A mother's diet doesn't significantly alter overall breast milk protein concentration; it's biologically regulated. Preterm milk is naturally higher in protein. Consult healthcare professionals for concerns about infant nutrition.

Conclusion: Context is Everything

The protein content per 100g of breast depends entirely on whether you mean cooked chicken breast (around 31g) or mature human breast milk (around 1.2g). Both are vital for nutrition but serve distinct purposes for different consumers.

Authoritative Outbound Link: For more detailed information on human milk composition and the nutritional needs of infants, the National Institutes of Health (NIH) is a reliable resource.

How To Maximize Protein Intake from Chicken

Choose boneless, skinless cuts to get the leanest protein source.
Opt for healthy cooking methods like grilling, baking, or poaching.
Measure cooked portions to get an accurate count of protein per 100g.
Pair chicken with other protein-rich foods like quinoa or legumes to create a complete meal.
Vary protein sources, as recommended by dietitians, for a well-rounded diet.

Nutritional Breakdown of Human Milk

Protein concentration naturally decreases as lactation progresses from colostrum to mature milk.
The whey-to-casein ratio is higher in human milk than in cow's milk, aiding digestibility.
Contains essential fatty acids crucial for brain and nervous system development.
Rich in lactose, which serves as the primary energy source for infants.
Provides critical immune factors and bioactive components that change with the infant's needs.

Frequently Asked Questions

The difference is due to water loss during cooking. As the chicken breast cooks, it loses moisture, which concentrates the remaining nutrients. Therefore, a 100g portion of cooked chicken contains a higher concentration of protein than a 100g portion of raw chicken.

While the fat content of breast milk increases during a single feeding session (hindmilk is fattier than foremilk), the protein and lactose levels are relatively stable during a single feed.

Human breast milk has a lower protein concentration than cow's milk. The protein types are also different; human milk has a higher whey-to-casein ratio, making it easier for infants to digest. Cow's milk protein is not suitable for young infants.

For most well-nourished mothers, their diet does not significantly alter the total protein concentration of their breast milk. The body prioritizes maintaining consistent protein levels for the infant's needs.

Colostrum is the first milk produced after birth. It is thicker and more concentrated, with a higher protein content (about 1.4-1.6g/100mL) compared to mature milk (about 0.8-1.2g/100mL). It is also rich in immune factors.

Yes, skinless chicken breast is the leanest and highest protein-per-gram cut of chicken, especially when cooked. Other cuts, like thighs and wings, contain more fat, which reduces their protein concentration per 100g.

In addition to being a rich source of protein, chicken breast provides B vitamins (like B6 and niacin), phosphorus, and selenium. These nutrients support metabolism, energy production, and overall cellular function.