“This is an act of desperation, what farmers used to call “eating the seed corn.” It will keep you alive but come spring, you’ll have nothing to plant.”
Eating treated seed corn would kill you long before spring!
The saying is anachronism. Hybrid seed can’t be harvested from the field anyway; it’s sterile.
But in the old days, it was fertile and wasn’t “treated.” It was as edible as anything you grew in your garden.