Thats what I thought at first, when I started 2 years ago. I was doing really healthy stuff, excersising and eating good foods, and I had this goal of loosing like 10 pounds...Then I started purging the unhealthy meals, then healthy meals that put me over the amount of calories I wanted, then just purging all the time. Babe, its not a healhty way to go. I would never, ever, ever, ever try and rationalise purging because it takes on a life of its own. Also, dont brush your teeth if you do purge, it rubs the acids even more into the teeth.
You sound like your not particularly bulimic or annorexic, so if someone were to diagnose you they would probably say you were ednos (eating disorder not otherwise specified) because you dont binge/purge which is what most bulimics do, and your not annorexic yet...
Anyways, an eating disorder like annorexia and bulimia is not always about loosing weight, while superficially it might seem that way, there are alot of underlying emotions like lack of controll, self respect, self esteem, feelings of worthlessness, often its away to release negative emotions you dont wanna deal with normally.
So in answer to your question, I dont think there is any way in hell you could be physically or mentally healthy while purging your food. Sorry, but please talk to someone about your urges and catch this disease before it takes controll of you, ok? Keep me posted! :) xoxo