Lack of sleep can hinder weight loss, especially if you're working out as well. Your body needs sleep to rejuvenate and prepare for the next day!
Whether or not you sleep those hours at night as "normal" ... that will just depend. My natural circadian rhythm is not set to go to bed at 10 and wake up at 6 or whatever. I am naturally a night-owl and do best when I go to bed around 3 and get up around 11 or so. It's one of the reasons that I enjoy owning my own business - I get to set my own hours and work at 2 a.m. if I want.
For me, that works. As long as I get between 5-6 hours of sleep a night, I do really really well. When I start getting less than that, my weight loss suffers. There are others who *need* 8+ hours. I have a friend who has to be in bed at 9:30 or he really does just become incapable of functioning - he even has a hard time stringing sentences together.
But he naturally wakes up at 5:30 every morning - no alarm needed - and runs 3-5 miles before breakfast (the freak!
So yes, weird sleeping patterns or lack of sleep can hinder your weight loss, but what's "weird" or "too little" is a very individual thing.