Due to a wonky school/work schedule and a weird phobia or two, lately I’ve been subjecting my body to eating only one (albeit pretty big) meal per day. In the past, if I had gone an entire day without eating until 9PM (and I do mean without eating a single thing, except for maybe chewing on some gum) my stomach would be very upset and I’d feel like I’m “starving.” For whatever reason, my body doesn’t do this anymore. I don’t even feel hungry during the day now and I run surprisingly well on no food (until of course the big meal that night). Why is this? Where did my appetite go? I’ll also gladly accept stern words on how bad this diet is for me. 
Check out this thread. I only eat one meal per day and have done so for all of my adult life.
me too.
This is currently being discussed on a number of fitness sites, where it’s known as “intermittent fasting”. It works very well for some people, mostly for fat loss but some people are even trying it for bulking.
I do this too, but I think I know where my habit came from. I am an avid user of a certain substance which induces bouts of extended ravenous hunger which has no correlation to your bodies actual need for food.
After using this substance frequently, I have found that I no longer get “hungry” without it. I still eat meals normally, I just find that I feel “full” extremely quickly, relative both to people around me and to the way I used to eat. Interestingly, the “full” I get after eating a small amount is not merely “satisfied” but quickly approaches the point where eating any more food would be extremely uncomfortable and possibly induce vomiting.
There are tons of weird things about my body and my lifestyle which don’t make sense to me, but I suppose many of them can be attributed to the fact that I am in college.
I do this for months on end.