Chris Kresser: Yeah, with sleep, it’s a U-shaped curve. Too little sleep is bad, and too much sleep is also bad. But my belief is that, in most cases, that’s an indicator of an underlying problem rather than that sleeping too much is actually causing the problem. However, there is some reason to believe that sleeping too much could also cause problems by disrupting the circadian rhythm. We’re kind of designed for a certain rhythm of sleep and wake. We evolved in an equatorial region where there are roughly equivalent amounts of light and dark throughout a 24-hour cycle and where we slept roughly eight hours in that 24-hour cycle, so any significant deviation from that in either direction can cause problems.