No. Leptin is mostly produced in fat cells, and if you diet too much, you won't have enough fat cells to produce all the leptin. Which would just give you insomnia
No. That's evolutional. Sleep is just more Important than food for survival in a cave-man-esque setting, which is what your body is adapted to. You'd be unable to get any food if you were sleepy. Your food would kill you before you could kill it