One meal. There may be a few exceptions but making one meal is very practical in everyone's busy schedule - no matter what generation. I was raised by a great loving family and there were 5 kids in all. The food was great but there were times when we objected but dad was very persuasive. This continued until we left home.
Making separate meals for young minds will just lead to demanding lazy adults who will do negative things if they don't get what they want.
Growing up with kids, we continued the tradition with the exception of some spouses that give in to children's demands. As adults we love to eat and cook and appreciate our parent's hard work of feeding us. Between children's activities, homework, maintaining the home, maintaining the car, and working, providing a separate meal just takes away from parenting time and may lead to becoming a parent that will be bossed around in the future. Children are keen enough to sense strengths and weaknesses.
The one meal does not apply when we go out in restaurants or go to pot luck parties. I may be strict but I can be flexible when I think it is appropriate.