Emily. Glad you hopped on board.
Yes it is very possible you aren't feeling hungry. If you old diet was eating highly processed foods then your body is getting much more fiber and more nutrients than ever before. Whole foods can be highly satisfying. Just don't eat tree bark for the sake of eating tree bark though
What I mean is don't eat something just because it is healthy because in order for you to stick with a plan, I think you really have to enjoy the food you are eating. Healthy AND good tasting is what you should be striving for so don't neglect the yummy factor. I am not sure if you are or not, but I just wanted to point that out. Sometimes when we arent enjoying the food we are eating, we also can lose our appetite.