I ** think ** the 'outposts' are level one settlements, in which you don't build housing, etc, but just use the  zone of influence to allow you to improve the wild resource tile.

If this is what level 1 settlements are designed for, then they should either not cost food, because they do not have any population, or should have a base of 10 or so population because they cost 1 food. 

I like the food cost. You still have to feed the workers manning your outpost, and when your troops stop off to heal, they've got to be eating something, right?

Also, without a food cost, you could spam them as movement blockers to make massive land grabs.