Figure 1.

Study protocol overview and sleep fragmentation procedure details. A) The study protocol consisted of a 6-day inpatient study with 2 nights of unfragmented (“unfrag”) sleep followed by 3 nights of fragmented (“frag”) sleep. Calorimetry (gray bar) was conducted in the fasted state on day 2 and day 6. B) Sleep was fragmented using an auditory stimulus delivered every 15 minutes that increased in intensity (60-90 dB) until wake was initiated, as indicated by the participant pressing an event marker (EM). C) Once initiated, wake was maintained for 120 seconds using an auditory stimulus and confirmed by an EM every 10 seconds.