We used to have a Red Lion near where I lived. It was a diner and they made the most amazing omelets. I'm talking half a plate size and the other half the plate was filled with potatoes. It was amazing. Man, I miss that place.
I have seen the sizes of dinner plates and their contents 'over there'. I think you would struggle here, or at least lose a couple of sizes if it would be a prolonged visit. They are intent on giving you less, as well as increasing the prices.
I don't really eat like I used to.... It probably wouldn't be that big of a shock.