Casein is one of the two primary proteins found in milk, the other being whey. Therefore, it can be obtained from milk, but is more commonly consumed as a protein supplement derived from milk. You can find casein protein in the form of powders, usually sold as "micellar casein" protein powder, in health food stores and online retailers.
This video discusses the impact of nighttime nutrition on muscle growth and preservation. Andrew Huberman explains the science behind how pre-sleep food choices influence the body's anabolic and catabolic processes during sleep, offering science-backed strategies to optimize muscle repair and growth.
Consuming casein protein before bed provides a slow release of amino acids into the bloodstream over roughly 6-8 hours. This keeps the body in an anabolic (muscle-preserving) state throughout the night, preventing the breakdown of muscle tissue that occurs during prolonged fasting while sleeping. A study from MRI University in the Netherlands showed that consuming casein protein before bed significantly increased overnight muscle protein synthesis.
Whey protein, conversely, is digested quickly and causes a rapid spike in amino acid levels within 30-60 minutes. This rapid digestion isn't as beneficial for overnight muscle preservation because the amino acid supply is depleted after a few hours. Therefore, casein's slow-digesting nature makes it superior for overnight muscle maintenance.