Feeding the world is mostly a political-economic problem. Political-economic decisions make it hard to feed everybody, when we technically have more than enough to feed everybody. But one of the decisions that make it hard to feed everybody is the decision to eat lots of beef in rich countries. Land that's used to grow food for cattle could (in many but not all cases) also be used to grow food for poor people, but there's no money in that.

That's not the only one; there's lots of other ways in which food is wasted or used inefficiently. Although the situation has improved tremendously over the past half century, there are still a lot of people suffering from malnutrition.