I try to get up at 4 am, but the reality is that I can't make it. It is caused by going to bed late. For example, I was able to turn off a room light after the midnight because I came back from work at 0:00.
One thing I can improve yesterday was to go to bed without eating a supper. 10 years ago, I got up at 4 o'clock in the morning every single day. Those days when I went back home after 10 pm , I ate nothing. In this way, I slept well and kept my shape slim enough!