언능 is a dialect of 얼른 which means "quickly,right now"
챙겨 먹어요 is composed of
챙기다 means "take,get,do not skip"
먹다 means "eat"
챙겨 먹다 means "do not skip meals; eat meals regulary"
언능 챙겨먹어요 means
Don't skip meals and eat them quickly right now.