Whey and Casein: All About the 2 Types of Protein in Dairy

Dairy is a nutritional powerhouse and a great source of high-quality protein. In fact, one glass of milk provides 8 grams of high-quality protein plus eight other essential nutrients, such as calcium, vitamin D and vitamin B12. Whey and casein are the two primary proteins found in milk, but what’s the difference between the two and how are they beneficial?

Check out this chart for the breakdown.

Whey – The Post-Workout Protein

Casein – The Bedtime Protein

Rapid digestion

Slow digestion

Promotes muscle repair and growth

Prevents muscle breakdown 

Affordable way to increase protein intake (about $18 per 2-lb. container)

Slightly more expensive way to increase intake (about $35 per 2-lb. container)

Commonly used right after a workout for maximum amino acid absorption and muscle growth

Commonly used before bed because of the gradual release of amino acids to the muscles over a longer period

Nutritional Facts: (per 1 scoop, 30 grams)

Calories: 120

Fat: 1.5 grams

Carbohydrates: 3 grams

Protein: 24 grams

Calcium: 10% of the recommended daily intake

Nutritional Facts: (per 1 scoop, 33 grams)

Calories: 120

Fat: 1 gram

Carbohydrates: 3 grams

Protein: 24 grams

Calcium: 50% of the recommended daily intake


Outside of preventing muscle breakdown and building muscle, both whey and casein contain bioactive compounds that have been shown to benefit overall health. In fact, studies show that diets higher in protein may help preserve muscle mass as we age in addition to helping with weight maintenance and satiety. The best option is a combination of both proteins, and milk is a great choice ­– with approximately 80% of the protein in milk coming from whey and the other 20% from casein.

While you can easily find whey and casein in protein drink mixes and energy bars, you might be surprised at their versatility. Unflavored whey protein is neutral in flavor, making it a great nutritious addition to soups, sauces, oatmeal, smoothies or protein shakes, baked goods and many other foods. Or make your snacks high protein and highly nutritious by choosing foods naturally containing whey and casein – like milk, yogurt and cheese – that will help keep you feeling full and satisfied!

“Milk” your competitive edge! Learn more about dairy and sports nutrition.

By Marley Oldham Carnes, M.S., RDN, LD, CSCS, CPT

Marley is a Registered Dietitian, NSCA Certified Strength and Conditioning Specialist, and ACSM Certified Personal Trainer. She has also worked as a fitness and sports director with the Navy and her father-in-law is a retired dairy farmer. In her free time, Marley enjoys hiking, cycling, running and volunteering with the Texas Academy of Nutrition and Dietetics. Learn more about Marley.

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