The world doesn't just starve because there's not enough food (which is what I assume you mean by that comment) but it can also be because there are too many people.
I am convinced that given access to birth control we'd be mostly able to control population levels without resorting to war and starvation. We are a plague upon the planet by any measurement. Something I read in a Jared Diamond book was fun... the desire for sex has the same relationship to babies as the desire to eat does to pooing.