Hi Sascraps,
.
You can have pizza on a diet. The main difficulty I've found is portion control.
It's just too easy to eat a piece or two...and then keep going until you wipe out
the entire pie.

Now there's an addiction I understand all too well. Mmmm...pizza.
.
When dieting, I generally don't keep it in the house. It's just too densely caloric,
and not very filling...and oh so very tempting. But every now and then...you just
gotta have your pizza.

As long as you keep the calorie consumption within reasonable
levels, giving yourself a 'normal' calorie day every now and then so you can have pizza can actually be part of your diet plan if you want to. It's not a "failure" if its part of your diet plan. And it should help you stick to your diet, if you occassionally plan to eat something you really really enjoy. (keeps you from feeling deprived, and gives you something to look forward to) So...maybe make every Satruday night pizza night (or some other high cal dish you enjoy equally)?

.
Best of luck on your diet.