It is fairly common for hunger-related NGOs to assert that world hunger is a distribution problem, not a production problem. They claim that the world currently produces enough food for 7 billion persons. But is this true? And how might we determine if the world agricultural system is currently able to feed 7 billion?
My analysis of the world agricultural system is found in these articles:
The Global Food Crisis: Feeding Ten Billion Persons – An Analysis of World Staple Crops by Macronutrients
Comparison of World Staple Crops [PDF] – with the associated charts here
The articles and charts analyze the top staple crops of the world and the contribution that they make to the protein, fat, carbohydrates, and total calories available to the world population. How can we characterize this relationship when there are hundreds of different food crops? We are able to do so because the world agricultural system is very top-heavy.
The vast majority of the kilocalories come from only a few crops: maize, wheat, rice, and soybeans each provide about 1015 kilocalories to the world, based on FAOSTAT data for production quantity and USDA data for nutritional content. Then there are several more crops that provide about 1014 kilocalories, and another slightly larger set of crops that provide about 1013 kilocalories. Before we reach the 50th top staple crop in the world, the contribution of each crop to world nutrition falls to about 1012 kilocalories. Crops at the 1012 and 1011 kilocalories level are orders of magnitude below the productivity of the top crops. One hundred crops at 1011 kilocalories each would supply only about 1013 kilocalories, which is one percent of the contribution of any one top crop at 1015 kcal.
So a list of the top 50 staple crops is sufficient for a good approximation of the total kilocalories produced by the world agricultural system. Adding a hundred more crops would have little effect on the total kilocalories produced by the world. And many of the crops not listed among the top staple crops do not produce substantial quantities of protein, fat, or carbohydrates; they are not staple foods.
How many kilocalories do 1 billion persons need per year? Ten to the 15th power kilocalories: one million kcal per person per year times one billion persons. Therefore, 7 billion persons need 7 x 1015 kcal/year.
According to my analysis, the top 50 world staple crops produce just over 1016 kcal, which is enough total kcal for 10 billion persons. Does this mean that the world produces enough food for 7 billion persons? Unfortunately, it does not. Human persons need more than the right number of calories per day; they need to have those calories appropriately apportioned among protein, fat, and carbohydrates.
Using a simplification of the Institute of Medicine’s recommendation for dietary intakes for macronutrients, calories should be divided so that about 15% of calories is from protein, 30% from fat, and 55% from carbs. The world agricultural system produces enough carbs for 13 billion persons, barely enough protein for 7 billion persons*, and only enough fat for 6 billion persons. So while the world produces enough calories, it does not produce enough protein or fat. If any population lacks carbs, it is a distribution problem. But for protein and fat, it is a production problem.
*The amount of protein produced would be sufficient, if there were no losses from field to table, no losses when plant protein is fed to livestock to produce animal protein, and no excessive consumption of protein in the Western diet. Therefore, from a practical point of view, the world agricultural system does not produce enough protein.
World hunger is caused by a lack of macronutrients, but mainly due to a lack of protein and fat. Most of the hungry have enough calories to survive, so they have enough or nearly enough carbohydrates. The three macronutrients are not of equal concern in addressing hunger. And this difference is reflected in the world agricultural system, which produces plenty of carbs, but not enough protein or fat.
The world agricultural system does NOT produce enough food for 7 billion persons, because the system produces too many carbs, and not enough protein or fat.