Huts should only cost 1 food but the real underlying problem is the card.
Cards don't tend to update while you are building within a city so studies will show one population amount but cost another.
Also, because the cards and calculations aren't updating, the game will allow you to over commit population resources which is a bug.
It would be really helpful if the info card that displays on the lower right showed both the current cost and base cost, rather than just the base cost. So if I have 3 markets in various towns and mouse over one of them, it would be much more helpful to show something like:
30 (3:10) rather than just 10.
