Big Facts on Climate Change, Agriculture and Food Security

Undernourishment and Obesity

  • Assessing precisely the current status of global food security is extremely challenging. However, the big picture is clear: About 2 billion people are food insecure because they fall short of one or several of FAO’s dimensions of food security (Wheeler and von Braun 2013 p. 509).
  • Globally, 842 million people are chronically undernourished, while almost 2 billion suffer from micronutrient deficiencies (FAO 2013).
  • Micronutrient deficiencies (’hidden hunger’) occur when diets fail to provide sufficient amounts of micronutrients such as iodine, iron, zinc and vitamin A. Micronutrient deficiencies increase morbidity and mortality, impair cognitive development, reduce learning ability and productivity, and reduce work capacity in populations as a result of higher rates of illness and disability—resulting in a tragic loss of human potential. Overcoming micronutrient malnutrition is essential for development (FAO 2012).
  • Some 65% of the world's population lives in countries where overweight and obesity kills more people than do factors related to underweight. Globally, more than 40 million children under the age of five were overweight in 2010. Once considered problems of only high-income countries, overweight and obesity are now on the rise in low- and middle-income countries, particularly in urban settings (WHO 2012).
  • The world is increasingly faced with a double burden of malnutrition, whereby undernutrition, especially among children, coexists with overweight and diet-related chronic diseases and micronutrient malnutrition. The reason for this coexistence is that being overweight is not necessarily a matter of eating too much food, but of eating food that is not nutritious, and poor consumers may have less access to good nutrition (FAO 2012).
Sources and further reading
  • [FAO] Food and Agriculture Organization of the United Nations. 2012. The state of food insecurity in the world 2012: Economic growth is necessary but not sufficient to accelerate reduction of hunger and malnutrition. Rome: FAO. (Available from (Accessed on 6 November 2013)
  • [FAO] Food and Agriculture Organization of the United Nations. 2013. The state of food insecurity in the world 2013: The multiple dimensions of food security. Rome: FAO. (Available from (Accessed on 6 November 2013)
  • Wheeler T, von Braun J. 2013. Climate change impacts on global food security. Science 341:508.
  • [WHO] World Health Organization. 2012. Obesity and overweight. Fact sheet No. 311. Geneva: WHO. (Available from (Accessed on 6 November 2013)