The UN established in its Millennium Development Goals (MDG) the ambitious goal of cutting world hunger by 50% in 2015-2020 in developing countries.
Hunger is the lack of basic food to provide energy and meet nutritional needs. Malnutrition is the lack of essential nutrients such as amino acids, vitamins and minerals. A person can be full but malnourished if they are not getting the right nutrition.
Undernourishment involves not having enough food for energy needs. This is common in developing countries such as India, Bangladesh, Pakistan, China, Ethiopia, Indonesia and the People's Republic of Congo. Sub-Saharan Africa has the highest percentage with 239 million people who are undernourished. Hunger and undernourishment lead to disease, stunted growth and earlier deaths.
Overnourishment involves eating too much and is common in developed nations. More than 1/3 of the US population is clinically obese at 30 pounds overweight or more. The best way to combat obesity is through exercise, healthy diet, hydration and enough sleep.
Hunger is common in areas that have experienced famines due to drought or conflict. A lot of Africa has experienced long-term, severe droughts and civil conflict.
Poor crop yields, rise in food prices and lack of food security have increased volatility.
The World Food Program (WFP) of the UN distributes global food aid with large donations from the US, Japan and EU. While the US and Canada have donated generously to end world hunger and succeeded in ending immediate famines, the problems of actually growing food locally and profitably for farmers still remains.