It may seem like going back to the old days of hunting and gathering but for obvious reasons resorting to these long lost ways of obtaining food is something that shouldn't be ignored!

Depending on the nature of the apocalypse, however, this can be dangerous and discretion is advised! Eating mushrooms and river fish might not be a good idea after a nuclear catastrophe. On the other hand, even in this scenario this might be your only option and secure at least short-term survival.

Unless you have to do not eat anything you are not sure about, e.g. berries can be poisonous. If you are so desperate that eating a certain fruit is your only option, start carefully and watch for symptoms before indulging in huge amounts of the unkown object.