Is it normal that my girlfriend eats pizza every day?

Not only is that not normal, it sounds like a health hazard. Try to ease her into some other foods, don't just push it on her or she won't eat it.

Just tell her she's starting to get a little chubby on the mid section there

What a shame as you seem to think she's a pretty special gal. Unfortunately for you, it would be best not to look forward to a very long relationship with this girl. Unless you will have enough money to cover some pretty serious medical bills, as her body begins to break down. She will probably be quite sickly after 35 or 40.
The food pyramid or diet pyramid was not designed to make the grocers rich, it was designed so even the stupidest person could understand what they need to know about eating healthy.

I'd say so. If you plan on sharing a future with her it seems reasonable to consider the types of food you'll be sharing and how that food you eat will affect your health. I admit, I have had urges to change or at least influence people's eating habits.

Eats pizza everyday... doesn't eat bread. Doesn't add up.

Yeah, you're concerned about her health, that's normal, not eating the pizza though, that's definitely not normal :P
Talk to her, such an amazing girl deserves a nice caring guy ;)

I forgot to mention , if it becomes a serious cause for concern on her health .. then worry and see if she will change .

How she eats pizza without consuming any bread is beyond me ? unless maybe she makes it herself or somehow knows a place who makes cauliflower dough or something? I dobt it but in any case , why the hell do you care what she eats? If she is a good woman , treats you well and is a "diamond" like you claim .. shouldn't you be pretty happy with all this and maybe not take it for granted? If she loves eating pizza , she loves eating pizza .. in the same token , it's apart of who she is . It might be a bit tricky for me since I love to cook and also I wouldn't want her packing on endless amounts of un healthy weight but if not .. my princess can eat whatever makes her happy .

Either duper picky or an eating disorder.
Pizza makes me break out :(
I'd suggest trying to broaden her food tastes but don't be pushy. Bring home some yummy new foods, you never know.

Skipping breakfast, eating pizza every day, and only eating certain foods. That sounds like the way I was two years ago. It's unhealthy and WILL eventually lead to some unwanted weight gain and believe me, it is a bitch to lose it. Perhaps you should sit down, have a calm talk about how her poor diet choices worry you and see of you can get her to try new foods.

Get Dr.Phil