Honestly, since I changed my eating habits (I used to eat a TON: those "betcha can't" 24+oz prime rib meals? Easy free meal!) I actually have trouble getting enough calories now!
The rule I use is I eat until I'm not hungry now, instead of eating until I am stuffed. As a result I tend to eat 5-7 times a day, but in much smaller portions. Since I started actually watching my calories my count has hovered between 1800-2200; usually on the lower end of that scale (when my recommended intake is around 2500-2600 to maintain.)
It's fine now, I'm losing weight and my body fat % is going down steadily, but I'm eventually going to get to a point where I'm going to want to build muscle again and bulk up and I'm kind of dreading having to go into a calorie excess now that being in a deficit feels so natural!