This book is the product of the Conference on Nutrition and Human Reproduction, supported and organized by the National Insti­ tutes of Child Health and Human Development, and held at the National Institutes of Health, Bethesda, Maryland, in February 1977. The genesis of this Conference came from the work of the Subcommittee on Nutrition and Fertility of the Committee on International Nutrition Programs of the National Research Council. The purpose of the Conference was to assemble scientists and program planners from a broad range of fields including nutrition, epidemiology, demography, endocrinology, sociology, economics, anthropology, biostatistics and public health. Each individual brought his or her analytical skills and perspective to the meeting, with the goal of developing a more coherent picture of the many facets of nutrition and reproduction. The approach was to get a more comprehensive view by: 1. Clarifying terminology and definitions. 2. Reviewing recent and current work on the biological basis for nutrition-fertility interactions. 3. Reviewing biomedical and socioeconomic factors related to breast-feeding to assess how this practice relates to maternal and infant nutrition and fertility. 4. Assessing some current analytical models for defining nutrition-fertility interrelationships. 5. Reviewing recent field studies from Africa, Asia and Latin America which are examining the interrelationships of nutrition and reproduction.