Of course I'm on a diet, we all are. (Or perhaps we all have a diet)
This is why these fad diets are stupid, diets aren't meant to be a silly thing that you do for a while, your diet is what you eat, and should be consistent.
As long as you exercise, you can eat what you want as long as you have fruit/veg and you're not eating fast food every week, or relying on ready meals.
I hate it when girls (as in not women) go on diets too. I mean unless you're eroding the door frame, or you're one of those child-blimps you see on TV, there's no reason to diet. I've never heard a guy say "she could do with losing weight" about a girl who isn't... overweight!