Mainly, as a chef, he's horrified by the idea of cooking without oil. I'm still getting over it myself. I'm half italian, so olive oil is a mainstay. Still, it's remarkably easy to saute onions and garlic in veggie broth, so oil suddenly doesn't seem that necessary.
Appears to me that oil primarily lets you turn up the heat, and cook faster. Traditional slow cooking doesn't need it. For example, if I simmer onions on very low heat, covered, for 1-2 hours, they turn very nice brown, without any burning.
Italians have so many fresh vegetables: eggplant, zucchini, radicchio, endive, fava beans, fennel and artichoke...
If I find a sauce that I feel really requires olives (very rarely), I toss in a few sliced whole olives, rather than using oil. Obviously, olives like avocados and nuts, are rich foods, and don't go well with loosing weight.
Dr. McD likes to say expect results.
Hopefully we'll be seeing some good Italian recipes from you. I'm reading a cookbook right now that has 140 Italian vegetable-bases sauces, however I've still got to adapt for no oil and no cheese.