The causes: some countries do not have the right conditions for growing food and agriculture. For instance the temperature could be either way too hot or too cold. Their could be over population, droughts, shortage of money, destructive weather/ wildlife, and lack of proper soil.
The effects: there are many outcomes from food shortages that are mainly all negative. For instance possible effects are, population shrinks as well as wildlife or domestic animals, erosion becomes a problem since primary food sources come from plants, which holds soil together with their roots, illnesses will become prominent, and possible migration of animals/humans will accrue because of the lack of food.
Hope this helps!