Maybe develop a list of favorite starters and sides that can fit both menus: soups, salads, hot vegetables, tubers and starches, egg dishes, fruit and dairy desserts--then learn how to quickly cook and add the protein portion separately (sort of like a restaurant menu). Excluding the all-meat meals and the all-bread/bean meals might be a fair compromise.
Kids can tolerate a lot of treats and empty calories but they should be homemade as much as possible. Industrial components are bad news at any age.
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