In the 1930s the Otomi ethnic group in Mexico became the subject of a broad scientific research program involving their metabolic and nutritional assessment. International agendas and the assumptions of contemporary racial science coalesced in an effort to understand the causes of the “backwardness” of this group. The aim of this paper is to show how Mexican physiologists and French medical expeditioners imagined the Otomi people as a group that could provide knowledge considered to be instrumental for creating public health policies in Mexico in order to “improve” the standard of living of indigenous people.