I have been traveling through New England and Upstate New York this summer. While driving on major highways, the meal choices are limited to major chains for the most part. Menu prices tend to be 10% higher at the rest area food courts.
Most of the popular concepts have strict portion control built into their service. I did not notice many changes in portion size. The main observation in the chain concepts was the tight control over complimentary condiments. Gone are the handfuls of ketchup and mustard. Napkins are also being strictly controlled at the grab and go locations. You need to ask for cream for your coffee at every place I visited.