How will you map the permission control between two entities?
One approach I thought of is to create a table 

producer_consumer_allowed (producer_id, consumer_id). 

A consumer is allowed to consume food from a producer if an entry for both this producer and consumer exist in this table. 

Whenever we add a new producer, we do not need to do anything since the default state of consumers-producers is No. 

Whenever we add consumers, we also do not need to add entires into this table since the default state is also No.