The first bracha of the birchat hamzaon says, in part, "Who nourishes the entire world" ... "He provides food for all flesh" ... "we have never lacked and we will never lack food forever". The second bracha has similar thoughts, "and for the provision of food with which You nourish and maintain us every day, at all times and in every hour". What meaning do these words have for those of us who have enough food and for those of us who do not have enough food?
This question is logically related to, but different from the question(s) on Ashrei. The discussions of a (the?) key verse in Ashrei are relevant, but that verse is open to various interpretations, including the words not referring to physical food. The words in the birchat hamazon are not open to that type of interpretation and are even more explicit than the peh verse in Ashrei. So, I do not think this and that question are dups and one does not provide an answer to the other, certainly not a complete answer.