World hunger refers to the want or scarcity of food in the world. The related technical term is either malnutrition, or, if malnutrition is taken to refer to both undernutrition and overnutrition (obesity, overweight) as it increasingly is, undernutrition. Both malnutrition and undernutrition refer to the effects on people of not having enough food.

There are two basic types of malnutrition/undernutrition. The first and most important is Protein-energy malnutrition (PEM). It is basically a lack of calories and protein. Food is converted into energy by humans, and the energy contained in food is measured by calories. Protein is necessary for key body functions including provision of essential amino acids and development and maintenance of muscles. Protein-energy malnutriton is the more lethal form of malnutrition/hunger and is the type of malnutrition that is referred to when world hunger is discussed. This leads to growth failure.

The second type of malnutrition, also very important, is Micronutrient (vitamin and mineral) deficiency. This is not the type of malnutrition that is referred to when world hunger is discussed, though it is certainly very important. Nutrients are the nourishing substances that we obtain from food. These essential substances are vital for growth and maintenance of a healthy body throughout life.

There are 6 classes of nutrients found in food: carbohydrates, lipids, proteins, vitamins, minerals and trace elements. These and water are essential for normal body function.

On the basis of the amount required by the human body nutrients are classified in the following two categories: macronutrients (carbohydrate, protein, fat) and micronutrients (minerals, vitamins and trace elements). Macronutrients, micronutrients (and water) are all necessary to promote growth and development and regulate body process.

Does the world produce enough food to feed everyone?

The world produces enough food to feed everyone. For the world as a whole, per capita food availability has risen from about 2220 kcal/person/day in the early 1960s to 2790 kcal/person/day in 2006-08, while developing countries even recorded a leap from 1850 kcal/person/day to over 2640 kcal/person/day. This growth in food availability in conjunction with improved access to food helped reduce the percentage of chronically undernourished people in developing countries from 34 percent in the mid 1970s to just 15 percent three decades later. (FAO 2012, p. 4) The principal problem is that many people in the world still do not have sufficient income to purchase (or land to grow) enough food.

Number of hungry people in the world:

The United Nations Food and Agriculture Organization estimates that about 795 million people of the 7.3 billion people in the world, or one in nine, were suffering from chronic undernourishment in 2014-2015. Almost all the hungry people, 780 million, live in developing countries, representing 12.9 percent, or one in eight, of the population of developing counties. There are 11 million people undernourished in developed countries (FAO 2014; for individual country estimates.

Children and hunger:

Children are the most visible victims of undernutrition. Black et al (2013) estimate that undernutrition in the aggregate—including fatal growth restriction, stunting, wasting and deficiencies of vitamin A and zinc along with suboptimum breastfeeding—is a cause of 3•1 million child deaths annually or 45% of all childdeaths in 2011 (Black et al. 2013). Undernutrition magnifies the effect of every disease, including measles and malaria. The estimated proportions of deaths in which undernutrition is an underlying cause are roughly similar for diarrhea (61%), malaria (57%), pneumonia (52%), and measles (45%) (Black 2003, Bryce 2005). Malnutrition can also be caused by diseases, such as the diseases that cause diarrhea, by reducing the body’s ability to convert food into usable nutrients.

“Food security is not in the supermarket. It’s not in the government. It’s not at the emergency services division. True food security is the historical normalcy of packing it in during the abundant times, building that in-house larder, and resting easy knowing that our little ones are not dependent on next week’s farmers’ market or the electronic cashiers at the supermarket.” ― Joel Salatin, Folks, This Ain’t Normal: A Farmer’s Advice for Happier Hens, Healthier People, and a Better World