When looking at your sov structures it lists the hourly upkeep costs.  In this listing it lists food as an upkeep cost along with the 4 basics, but below in the upgrade portion it only lists the 4 basics as an hourly cost.  Furthermore if you look under your resources tab, it correctly shows a -### amount in basic sov structure upkeep, but nothing under food.

Now I know that sov structures don't cost food per hour as upkeep, but this can be confusing for players who are not completely familiar with sov costs.