Blended family troubles

I am in a blended family we were raised differently. I don't believe in force-feeding my children I believe they'll eat when they're hungry he believes they should eat what's given without question. How do we over come the diffences? My children are 17, 14 and 9. My oldest doesn't eat very much in general. And my youngest is super picky. His kids eat anything he makes without complaints because that's how they've always been raised, same with him.please help with sharing your experience and what's helped your family over come this issue. Thank you so much.