Minimally feed one? Yes. Feed, clothe and care for them "properly", so that measures of their total health (like for example, their height) wind up in strong greater-than-or-equal correlation with parents who are already decently-off? Takes a bunch of effort.
Food is expensive for a large family with a decent mortgage payment. Also, Remember when you have a family your career mobility drops dramatically. I know I won't have kids until I am 30, without going into debt of course.