Average pizza slice that we're discussing is according to https://www.nutritionix.com/i/nutritionix/new-york-style-piz... 500+ calories, lots of saturated fat, lots of sodium.
How healthy is it to grow up on pizza?
See USA statistics for obesity, diabetes, hypertension, and heart disease.
Pizza is relatively benign.
The problem with sugar is that it is half fructose, and fructose is processed on the same pathway as alcohol, in the liver, and causes the same illnesses as alcohol. It is much better, if you must eat it, to eat enough fiber with it that your intestinal bacteria get much of it instead.
If you don't keep your intestinal bacteria well-fed, they are obliged to eat you instead.
Glycemic index is vastly different when it’s combined with protein and fat.
It’s not going to have a lot vitamins, but it’s pretty balanced in terms of the carb/protein/fat
You’d do worse eating a plate of white rice with soy sauce.
Unless you’re excluding the cheese, this is way off
What does it matter which ingredients people do and do not consider healthy?
It is objectively known that the quantities of bread and mozzarella consumed by most people relative to their lifestyle is unhealthy.