Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past several decades.[1] In 2006, MSNBC reported that globally, the number of people who are overweight has surpassed the number who are undernourished - the world had more than one billion people who were overweight, and an estimated 800 million who were undernourished.[2] According to a 2004 article from the BBC, China, the world's most populous country, is suffering from an obesity epidemic.[3] In India, the second-most populous country in the world, 30 million people have been added to the ranks of the hungry since the mid-1990s and 46% of children are underweight.[4] 

 Worldwide around 852 million people are chronically hungry due to extreme poverty, while up to 2 billion people lack food security intermittently due to varying degrees of poverty (source: FAO, 2003). Six million children die of hunger every year - 17,000 every day.[5] As of late 2007, export restrictions and panic buying, US Dollar Depreciation,[6] increased farming for use in biofuels,[7] world oil prices at more than $100 a barrel,[8] global population growth,[9] climate change,[10] loss of agricultural land to residential and industrial development,[11][12] and growing consumer demand in China and India[13] are claimed to have pushed up the price of grain.[14][15] However, the role of some of these factors is under debate. Some argue the role of biofuel has been overplayed[16] as grain prices have come down to the levels of 2006. Nonetheless, food riots have recently taken place in many countries across the world.[17][18][19] 

 It is becoming increasingly difficult to maintain food security in a world beset by a confluence of "peak" phenomena, namely peak oil, peak water, peak phosphorus, peak grain and peak fish. Approximately 3.3 billion people, more than half of the planet's population, live in urban areas as of November 2007. Any disruption to farm supplies may precipitate a uniquely urban food crisis in a relatively short time.[20] The ongoing global credit crisis has affected farm credits, despite a boom in commodity prices.[21] Food security is a complex topic, standing at the intersection of many disciplines. 

 A new peer-reviewed journal of Food Security: The Science, Sociology and Economics of Food Production and Access to Food began publishing in 2009.[22] In developing countries, often 70% or more of the population lives in rural areas. 

 In the US, there are approximately 2,000,000 farmers, less than 1% of the population. A direct relationship exists between food consumption levels and poverty. Families with the financial resources to escape extreme poverty rarely suffer from chronic hunger, while poor families not only suffer the most from chronic hunger, but are also the segment of the population most at risk during food shortages and famines. 

 Two commonly used definitions of food security come from the UN's Food and Agriculture Organization (FAO) and the United States Department of Agriculture (USDA):