Let me just list off my ideas for this concept:
- A kid anomalously is always able to eat its favourite kind of food.
- Was found in a well, in which birds constantly threw completely edible noodles from a chinese place.
- Several ingredients from that place are only available regionally. Extinct everywhere else.
- Foundation contains as Foundation does.
- Testing confirms a change in taste to equal a change in the affected food and its availability.
- Big Bad Spoop starts wiping out humanity. Extinction is literally the effect of that other thing.
- Plan for a "diet change" is made, out of desperation.
That is as far as I got so far. If anyone could throw in a few ideas, that'd be great.