Same here!
I've been on and off vegetarian since I was 2...then for the last 4 years vegan. I've been eating white meat for the last few months so it's a different type of protein. I'd recommend keeping track of it for a couple of days and see if you're eating enough. Maybe you are, may you are not...and if you're not you've found out why you're always hungry. Et voila!
If you are getting enough, then there's something else.