Acknowledgments

Special thanks are due to the Maya Cakchiqueles of Santa María Canqué, always generous and forgiving for whatever inconveniences were brought to them by the clinic's activities. We did not teach them much, but we certainly learned from them most of what has been written here. Many worked on and contributed to the study, among them Juan Urrutia and Carlos Beteta (pediatrics); Bertha García, Gustavo Linares, and Emma Blanco (dietetics, field work); Olga Roman and Palmira Dardón (nursing); Juana Cutzán and Candelaria Valle (midwifery); Raúl Fernández, Olegario Pellecer, Elba Villatoro, Roberto Rosales, Adelaida Comparini, Luis Sanchez, and Horacio Mazariegos (microbiology studies); and Eudelia Ortiz, Mélida de Tenas, Josefina Hernández, and Jose Luis Gonzalez (cleaning). The following students participated in the study: Amanda Negreros, David C. Dale, Celina Carrillo, Armando Cáceres María Laura Mejicanos, Miguel F. Torres, Robert Morhart, Richard G. Wyatt, Jose R. Cruz, David Martin, Dan Cherkin, Wendie Branwell. Most of the processing and discussion of data were cone with Richard A. Kronmal, John E. Gordon, Claire Joplin, Constantino Albertazzi, and Eduardo Arellano. Important guidance, advice, and stimulus was proffered by Nevin S. Scrimshaw, John E. Gordon, Joaquin Cravioto, and John P. Fox. Valuable secretarial assistance was given by Ada Luz Colmenares, Marion Landsberger, Patricia Sole, and Patricia Morales. The study and analyses were funded by the National Institutes of Health, the US Agency for International Development, INCAP, the Pan American Health Organization and PAHEF, the Guatemalan Ministry of Health, American Cyanamid, the School of Public Health and Community Medicine (University of Washington), and INISA (University of Costa Rica).