Comparing whey and casein protein powders

What is the difference between whey and casein protein? 
Whey protein digests much faster than casein protein. Whey protein is best used as part of a meal, specifically a meal before or after training. Casein digests slowly, which will help keep you feeling full, and will continue to deliver a steady stream of protein to your muscles for a long period of time. Casein is best used prior to long periods of time without a meal, such as before bedtime, or on busy days when you might not be able to eat regularly.

What is whey protein? 

Whey protein is a milk-based protein created from the cheese making process. It’s ultimately sold in powder form. Whey protein is known as the “fast digesting” protein, because it’s easily absorbed and digested, and enters the bloodstream quickly. Whey protein results in rapid delivery of amino acids (protein) to the muscles.

When is it best to consume whey? 
Whey protein is an excellent option to consume before, during, and after workouts, due to the fast delivery of amino acids (protein) to the muscles. Plus, its easy digestibility reduces the chance of GI distress around training. Whey protein is also a high quality, versatile, and convenient protein source that can be incorporated at ANY meal or snack.

Can I use whey to replace a meal? 
Yes, you can substitute a whey protein shake for lean protein at a meal, but it should NOT be your primary protein source throughout the day. Variety ensures that you consume sufficient vitamins and minerals. If you are in the habit of having shakes to replace meals, mixing Whey and Casein together is probably best to meet meal replacement protein needs: just mix 1/2 of one with 1/2 of the other.

What is casein protein?
Casein protein is also a milk-based protein, derived from the cheese making process. It’s touted as the “slow digesting” protein, because it takes 5 - 7 hours to digest. This is because casein protein literally “clumps” in your stomach.

If you’re concerned about the health and safety of Casein protein, please don’t be. Casein has NOT been shown as a carcinogen of note in humans and is highly unlikely to be unhealth in the context of a balanced diet.

When is it best to consume casein?
Casein protein is best consumed prior to a long period of time without food, such as right before bed, or a busy day of meetings. Its slow digesting nature will provide satiety and a steady supply of amino acids to your muscles for a prolonged period of time. 

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  • Is it okay to mix whey protein powder with (whole) milk before/during/after a workout if the main goal is muscle building? Or will the fat from the milk slow the protein digestion too much?

  • Hey Josh, 

    Excellent question. For intra-workout shakes, we recommend keeping the shake fat-free. 


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