The participants at the food summit organized by the Food and Agriculture Organization (FAO) in 1996 pledged to reduce the number of hungry by half by 2015. Measuring and quantifying food insecurity is a crucial component of making progress towards that goal. This paper presents one possible approach towards measuring what share of the population might be affected by food insecurity and to what extent. A food security threshold can be calculated as the sum of the cost of a food basket and the cost of other basic necessities. This food security threshold can then be compared to available income. We calculated two food security threshold levels, one based on a representative healthy food basket and one based on a low-cost healthy food basket. The approach is illustrated for nine lower income Latin American countries. To examine the implications of skewed income distribution on food security, we allocated national income across five income groups within each country according to income distribution data from the World Bank and then compared these per capita income levels of the five quintiles to the food security thresholds. Honduras and Nicaragua were found to be the most food insecure countries with 40 percent of the population estimated to be unable to afford the healthy low-cost food basket.