I'd go with this.
Most of the stuff in supermarket chains are branded food products which are mostly all toxic. 'Chains' and 'brands' are slave terminology.
A seeming food shortage encourages people to shop local fresh too, and where possible, start growing their own, and/or barter skills in exchange for services/food.
The same was enacted with the manufactured petrol shortage. All the pumps amassed a lot of thick crude sludge in the tanks below ground during shut-down when demand for supply plummeted. It was a way of clearing out all the old fuel quickly, and people duly obliged. People will similarly empty shelves.
Supporting local farmers market is great also. I have noticed on my travels (UK) that these are popping up now in various locations.