The “ Problematic ” Otomi: Metabolism, Nutrition, and the Classification of Indigenous Populations in Mexico in the 1930 ’ s Joel Vargas-Domínguez National Autonomous University of Mexico In the 1930s the Otomi ethnic group in Mexico became the subject of a broad scientific research program involving their metabolic and nutritional assess- ment. 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. 1. Introduction In post-Revolutionary Mexico, the Indian was conceptualized as a problem that needed to be solved. Indians were believed to be weighing down the nation and thought to constitute an obstacle for fulfilling its promised modern future (Bartra 1974). Thus, the scientific study of indigenous peo- ples in Mexico became, in the 1930s, a focus of anthropologists, physi- cians, and other experts, who sought to learn more about indigenous populations in order to solve this “problem. ” In this paper I explore how this “problem-solving” was practiced, how and why particular groups of people were used as subjects of inquiry and intervention, how they were selected, and how they enabled the production of knowledge deemed useful to the state for improving the living conditions of these groups, in resonance with national and international public health goals. Importantly, despite the sizable literature focusing on the construction of Indians as problematic, less attention has been paid to the actual practices Perspectives on Science 2017, vol. 25, no. 5 © 2017 by The Massachusetts Institute of Technology doi:10.1162/POSC_a_00254 564