Prosciutto is often eaten with melon, or with figs, so yeah it's processed meat, but then it's eaten with fiber and healthy micronutrients.
Mozzarella could be a problem too (center of Italy), eating a mozzarella with tomato and basil (caprese) is simple, yet the mozzarella is loaded with calories.
Then again, most dishes in Italy use natural ingredients, but that doesn't spare you from getting fat. Take pasta with egg and guanciale (carbonara) is a ton of calories even if home made
I wonder if biscotti is the real deal. In Italy, kids have breakfast with a cup of milk and X amount of biscuits, those are sugar, flour, egg, milk and something else to give flavor. Eat 4 of those and it's 200 calories. Eat 8 of those and it starts to get scary (400 calories) + 1 cup of milk = ~550 calories.
This would be funny to hear for you, but to become fat in the south you just have to have a good appetite: most moms, grandmas and aunts will cook you INCREDIBLE meals (very flavorful stuff), but of course it will also be loaded with fats.
The likelihood of this being a problem related to preprocessed stuff is low
BIG FARMERS BREAKFAST, and many types of breakfast foods are largely a marketing invention; many societies never ate large breakfasts, and many still don't, e.g. the soup & natto breakfast in Japan