The answer to this is as varied as the number of developing countries, of which detailed analysis is being added to this FAQ regularly. There are some general patterns that emerge, however.
Hunger is often the result of direct political decisions.
Famine in Ethiopia in the 1980s, for example, was not a natural disaster, but in fact was the direct result of decisions made by the government to starve out areas controlled by rebels. More recently the government of Sudan briefly ordered United Nations relief flights to stop airlifting food supplies to famine-prone southern Sudan controlled by rebels trying to overthrow the government. Famine in our century has become almost exclusively a political rather than an agricultural phenomenon. Government policies often artificially reduce the amount of available food. To achieve that, many nations placed price ceilings above which farmers could not sell their grain.