Energy needs and time of day

I wasn’t sure where to post this. I notice that I need to eat small things every hour from around 9-3.. then my appetite is much lower towards the end of the day. (This used to be the opposite for me). I have noticed since I have put on a good amount of muscle that I am also hungrier in the morning. Are muscle, metabolism, and hunger all intertwined? Do they effect the time of day you are most hungry?