Whenever I see footage of a single mum with a hungry kid or kids she iz over 100kg.
Me myself I don't hav any breaky, I hav a banana for lunch. And I am happy with spuds for dinner.
No candy, no soda, no cookys.

But I think my main point anyhow woz that if u had zero population growth then there would be zero need for new subdivisions new schools new houses.
The next step would be one kid per family -- in eech generation the number of houses owned by familys would double -- 1, 2, 4, 8 etc, without limit.