And, focusing on calories alone doesn't tell you anything about the quality of the calorie -- the nutrients available to the population. Also, this type of estimate is also based on the information each country provides. Some nations don't have the resources to be able to collect such information even every five years. So, it's really an incomplete picture."

The survey asks participants a series of questions regarding their household food situation in the previous three months. For example, it asks if the household had run out of food in that time period because of a lack of money or other resources, or if, for the same reason, any adult or child in the household had to skip meals or reduce portion sizes. Other questions ask whether the household could afford a nutritious, varied diet, and how frequently the household experienced such situations.

Development of ELCSA began about 10 years ago when both Brazil and Colombia wanted to set up methods to collect food insecurity data.

"For the first time in history, we had national food security data from two Latin American countries, but it wasn't comparable because they weren't using the same scale," Melgar-Quinonez said. "With ELCSA, we merged the two surveys -- what we as a group wanted was one scale, the same for all countries."

ELCSA is similar to the U.S. Household Food Security Survey Module used by the U.S. Department of Agriculture's Economic Research Service (http://www.ers.usda.gov/Briefing/FoodSecurity/).

"It's this measurement that shows that single mothers sometimes have three times the national rate of food insecurity, or Hispanic households have double the rate," Melgar-Quinonez said. "We can identify groups at higher risk, then target programs to help them."

Part of Melgar-Quinonez's work has been to analyze the validity of the survey. In 2010, he received an FAO Research Award -- one of just five given globally -- for his work in comparing the performance of the tool in Mexico, Colombia and Guatemala.

"We found some differences -- we need to work on some issues to make ELCSA an even better tool," he said. "We have offered regional workshops -- five in Central America in 2010 and five more in South American countries in 2011. We want everyone to measure exactly the same way."

In fact, Melgar-Quinonez just returned from a week in his home country of Guatemala doing some consulting on ELCSA. At a press conference, he presented the most current data on food insecurity for that country. ELCSA will also be used to evaluate the national program against hunger in Guatemala.

Currently, at least some application of ELCSA has been adopted in Mexico, Guatemala, El Salvador, Nicaragua, Colombia, Ecuador, Bolivia, Paraguay, Peru, Brazil, Uruguay, Haiti, with Dominican Republic, Cuba, Venezuela, Chile and Argentina considering beginning use this year. In addition, translations -- some of which are being done by Melgar-Quinonez's graduate students and recent graduates -- are under way for use of the tool in Albania, southern China, Ghana, Uganda, Palestinian territories and Indonesia. The goal, Melgar-Quinonez said, is to document the severity of hunger and malnutrition in different populations, allowing policy-makers to develop strategies to help those most at risk.