Figure 1.

Schematic representation of the experimental protocol. Subjects participated in 2 experimental sessions presented in randomized order: one session involved 2 nights of 10 hours in bed (dark gray bars), and the other session involved 2 nights of 4 hours in bed (light gray bars). Sleep was polygraphically recorded during each night. After the second night of each experimental session, bedtimes were at midnight, blood and salivary samples were obtained at 20-minute intervals from 9:00 am to midnight and from 2:00 pm to midnight, respectively, while meals were replaced by constant glucose infusion at a rate of 5 g/kg/24 hours and measures of perceived stress, hunger, and appetite were obtained at hourly intervals.