Would calorie labels make me order differently in restaurants?

Absolutely. Wouldn't you?

There is no doubt in my mind that if I knew how many calories were in every dish I was thinking about ordering, it would affect my decision-making. That doesn't mean I'm going to opt for the lowest calorie option for every course. That would require me being denied the great pleasure I derive from food. What it might mean is that, if I order the lasagna, I might eat half of it and give the rest to my dining companions and then opt for the steamed fish with ginger and black beans.