Many Latin American countries, such as Mexico, Guatemala, Bolivia, Peru, and Ecuador, have large indigenous populations. These groups are generally the poorest and least educated, as well as the most growth retarded or stunted.1,2 The question arises whether the high levels of stunting recorded among indigenous peoples are a result of poverty or are also (or instead) indicative of bias introduced by using an inappropriate reference population-that is, by using the National Center for Health Statistics-World Health Organization curves, which are derived from studies of US children of Northern European ancestry.3