Well, for this one, I'm not sure I totally agree. Food has always had an expiration, so I'm not sure how it would connect to obsoleteness. Are you more referring to consumer food not being as sustainable as farm-grown food? Not everyone has the luxury to grow their own food, so food bought in groceries are born not only for convenience but because of the situation.
It's more as though the idea of giving away what we don't use right now has become obsolete or not picked up. For instance, in Austria they have a food store to which packaged food and other goods is delivered that are about to expire but are still usable, so those on the poverty line or below can shop there for 50-70% discount, or less. They had it here but it didn't pick up because the stores didn't deliver any or enough goods. Maybe I put the wrong photo up - I have one of the parcel where the urban gardeners were chased away, but then the housing bubble hit here and they didn't bulid the block of flat they wanted to build there, and some family whose family members were laid off from that construction company simply decided to make themselves a squat garden there. I read somewhere that municipalities over the planet have their unused parcels that could be rented out if a group of citizens would demand it. In USA they had also the initiative where local restaurants decided to pack the left overs of the day and someone delivered them to the homeless shelter.
I have read in Marco Polo's Travels that even such horrible person as Kublai Khan enacted the idea given by someone to create storages for grains all over China, where the stored grains lasted for 4 years, and were delivered to the poor in times of need, so they wouldn't need to sell their own children.
I referr also to the luxury we once had to learn from the childhood on how the plants are grown and harvested and also to the luxury to go out into the nature and be able to pick what there is edible in reasonable amounts. I also referr to this seemingly never ending unbalance of somewhere being a heap of food away and somewere else this never ending lack. I was risen in the idea of don't throw away food, unless it is already bad, so it strikes me always when I encounter such disparities. Maybe this idea has become obsolete and me too old. Wheew!
Ah yeah I get what you mean. I think your clarification does a fine job of clearing it up.