Processed foods do their damage over many years so it's easy to be skeptical. Maybe focus on nourishment and point out how the bread and pasta don't contain as much as squashes, yams, and fruits. I notice a lot of families fall into the bread/pasta trap because the kids grow too attached to the familiar and refuse to try new things, so maybe the best approach is to share recipes and photos reminding them of all the great alternatives out there.
Lots of: urban hiking, cycling, sprinting
Lots of: fresh meat, seafood, eggs, organs, tubers, starch fruits, vegetables, meat fat, dairy fat, oil fruits
Some: cured meat, dairy protein, sweet fruits, rice, pulses, tree nuts, oil seeds
Minimal: soy, refined proteins, sugar, liquid carbohydrate, grains, refined oils, peanuts