Cindy Holleman, an economist working with the UN Food and Agriculture Organization, is certainly right when she identifies the three main reasons of increasing hunger around the world as
1. Conflict--aggression and wars
2. Climate Change--extreme weather, droughts floods
3. Economic stagnation--slowdowns and downturns
But let's cut through the bullshit here: the real reason why hunger is growing year to year is due an economic/political system (neoliberal capitalism) that legally legitimates and indeed, encourages, corporations and governments to put profit ahead of human beings, ecosystems and the biosphere.
There is absolutely no good reason why there should be hunger anywhere in the world--and there is no reason why people should have to rely on cheap unhealthy food in order to simply survive. All of the above causes of world hunger: wars, Climate Change and Economic stagnation--are directly or indirectly caused by this destructive system of economics.
We don't need new technologies or more efficient agricultural systems, but rather a wholly different economic/political system.