In this article, we critically review the three most common approaches of assessing chronic food insecurity and undernutrition: (i) the FAO indicator of undernourishment, (ii) household food consumption surveys, and (iii) childhood anthropometrics. There is a striking and worrying degree of inconsistency when one compares available estimates, which is due to methodological and empirical problems associated with all three approaches. Hence, the true extent of food insecurity and undernutrition is unknown. We discuss strengths and weaknesses of each approach and make concrete suggestions for improvement, which also requires additional research. A key component will be the planning and implementation of more comprehensive, standardized, and timely household surveys that cover food consumption and anthropometry, in addition to other socioeconomic and health variables. Such combined survey data will allow much better assessment of the problems' magnitude, as well as of trends, driving forces, and appropriate policy responses.