Certain parts of the world, mainly in the Global south, are particularly susceptible to malnutrition. Malnutrition can be caused by a lack of food and nutrients and can cause diseases such as anaemia to become wide spread, while also having an impact on long term health conditions. It can also be developed when not enough varieties of food are consumed, meaning that the person does not get the variety of nutrients that they need to stay healthy. The primary reason for malnutrition is poverty and the inability to buy food to eat. This is caused by in areas of the world where a high proportion of the population lives below the subsistence level, where they do not earn enough money to stay healthy. For populations that are dependent upon subsistence farming, being malnourished can have a cyclical effect of farming as farmers are unable to produce crops and so malnutrition and poverty become worse. Widespread illness, such as HIV/AIDs or malaria in sub-Saharan Africa also mean that farmers are unable to work the land, and so this means that they do not have enough food to eat, or enough food to sell to buy enough variety of foods. For countries that are unable to import a reliable amount of food, natural hazards also cause huge issues for malnutrition. Heatwaves can destroy an entire harvest of crops and lead to malnutrition and widespread poverty, as is the case in East Africa. Other natural hazards such as earthquakes in the case of Haiti, following the 2010 earth meant that levels of malnutrition as infrastructures were destroyed and farming could not take place and making them increasingly reliable on international food donations.