system
Given the following post, respond as if you're commenting on Reddit:
human
[Fallout] what kind half-life does blamco mac & cheese have? It has to have been out of production/expired for 200 years by the events of FO4.

Same for salsbury steak, pork and beans cans, etc. Maybe the radiation keeps it from deteriorating?
gpt
The great war wasn't that much of a shock to Americans by 2077. (The timing was, but not so much the fact that China finally resorted to the nuclear option) The world had been at war for decades by then, tearing itself apart over dwindling resources in increasingly bloody wars. The European Commonwealth had destroyed the Middle East in nuclear fire, then tore itself apart as its last gasoline reserves dried up. China had been fighting America for years as well, and everyone was just waiting for the moment to come when the nukes started flying just like they did for Europe. 

In this fearful and paranoid climate, most food producers in North America started marketing their products as "bomb-proof" and "ultra-stable". Not only had packaging been completely redone to make everything as airtight as possible, but most every food sold on shelves had been re-engineered by chemicals and nuclear treatment to be as stable as possible. Food was no longer being sold on its nutritional, aesthetic, or even taste value. By 2077, most pre-packaged American food was being sold on how well it would survive the coming apocalypse. 

None of it was actually meant to survive for 200 years, of course. But the sheer industrial spirit of pre-war America for exploiting the common people in pursuit of profit is what has saved many a wastelander from starvation.