Maybe it was different for you, but when I was growing up, my parents’ lifestyle didn’t change very much, which for us meant our mealtimes rotated through a catalog of "Standard American Diet" fare: bread, eggs, American cheese singles (individually wrapped in plastic), fried chicken, mashed potatoes and gravy, meatloaf, hamburgers, hot dogs, mac and cheese, salty soups, sugar-laden salad dressings, and so on.
After I had children of my own, my parents (well, my mother mainly) became more aware of diet-related health concerns right around the same time I did as well. But where my mom stopped at Whole 30, I decided to go from quasi-paleo to becoming full-fledged vegan.