I think it makes a difference. We have both a formal dining room and an eat-in kitchen (the kitchen actually seats 6 and the dining room seats 12). Only for meals served in the dining room do I ever compose plates. Usually it's just the 4 of us and we serve ourselves from the stove... I don't even put the food into pretty dishes. That's the weeknight routine, as we eat at home almost every single night. A couple times a month we eat in the dining room on the china and yes, I do try to compose a pretty plate because my table service is also very pretty, imo. Mostly, though, no, I don't worry too much about plating and let the family serve themselves.
However, a couple years ago I started making a Bento lunch
for my daughter (she's 8 now). She has never been a picky eater, but she is a talker and she wasn't finishing her lunch at school and coming home starving because she talked instead of eating. Once I started packing Bento boxes, she is IN LOVE with her lunch enough to shut up and eat.
I'm not serving any different food, just presenting it differently, so obviously there is something about presentation that does something... at least for young kids.