Thanks for the welcome!
As I read the source above, I was agog with the quantities eaten not just on special occasions, but day-in and day-out, and not just by the rich, but by ordinary farmers and clerks. On one hand, there were indeed many more courses in the 19th century, but on the other hand the accounts said that, for example, the cuts of meat served were normally thick. So how much food did each course amount to, by some quantitative measure? I guess I do not know. Still, that stomach complaints were such a widespread problem in America in the 19th century, and that by the beginning of the 20th century they were not seems to me evidence that overeating had diminished.
I've heard and read, of course, that in America between a century or a half-century ago and now, there's been an increase in calories consumed. But I don't really know the data, so I perhaps should sit out discussions about this period. I'm going to go out on a limb anyway and say that I'd be surprised if this increase is nearly as drastic as the decrease in calories consumed between the mid 19th century and the start of the 20th.