“I bought him some fancy cat food, but he just turned up his nose at it.” 「高い餌を買ってやったけど、食べなかった。」

“I try to feed my kids healthy, but they always turn up their noses at vegetables.” 「子供たちに健康的な食べ物をと思っているけれど、野菜を食べようとしない。」

「turn up your nose at~」とは何かを拒絶することを意味します。特に自分にふさわしくないと思うものに対して。

To “turn up your nose at” something is to reject it, especially because you think it’s not good enough for you.