If food were charged by the ounce when dining out, would that change the eating habits in the US, or would people just stay home and stuff themselves?

I was at a medical center’s cafeteria, after I was done with the lab, and went to the sandwich bar, because I did not want a whole lot, just something to kill the hunger. I made what I thought was a simple sandwich, at least compared to those my friends would have made, and when I checked out, I was told to put it on a scale and based off the weight of the sandwich, I was charged how much the sandwich was. I would not have paid that much for a sandwich that simple anywhere else. I was thinking if it were a sandwich any of my friends made they would have been charged around $7 to $10 dollars on average. That got me thinking, if one went out for steak, pasta, etc. and was charged by the total weight of the meal and not by what the meal is, would that change the way people dinned out in the US? Would they eat less, smaller portions, would they pile it on and just pay the price, would they forgo eating out and just stay home where they can stuff themselves to their hearts content?