In this special episode, Matthew Walker returns for his third AMA episode to provide his expert insight into numerous sleep-related questions directly from listeners. He explains how he adjusted his hypotheses on topics like blue light and caffeine, and why he is more bullish on the importance of REM sleep. Matt also answers questions about sleep wearables, how fasting affects sleep, how sleep deprivation impacts gut health, and magnesium as a sleep aid. Finally, Matt reveals what he believes is the next evolution in sleep science and technology. If you’re a subscriber, you can now listen to this full episode on your private RSS feed or on our website on the show notes page. We discuss: • Matt’s framework for changing his mind when faced with new information [1:30]; • Blue light—How Matt shifted his thinking [5:45]; • Caffeine—How Matt has adjusted his hypothesis [12:00]; • REM sleep—Why Matt is more bullish on the importance of dream sleep [16:30]; • How to increase REM sleep [27:30]; • Sleep tracking wearables—criteria for evaluation, and why Matthew favors Oura [35:00]; • Does the electromagnetic force of devices have any impact on sleep? [40:15]; • The relationship between fasting and sleep [46:15]; • Restless leg syndrome [58:10]; • Magnesium supplementation as a sleep aid [1:03:00]; • The relationship between sleep deprivation and gut health [1:08:30]; • The next evolution in sleep science and technology [1:16:30]; • Questions Matt would like to explore if money was no issue [1:24:15]; and • More. Learn more: https://peterattiamd.com/ Show notes page for this episode: https://peterattiamd.com/matthewwalkerama3 Subscribe to receive exclusive subscriber-only content: https://peterattiamd.com/subscribe/ Sign up to receive Peter's email newsletter: https://peterattiamd.com/newsletter/ Connect with Peter on Facebook | Twitter | Instagram.