ABSTRACT
<b><big>Introduction</big></b><br>Women in northeast Asian countries follow special practices during prenatal and postnatal periods. The traditional ‘<i>Yu fai</i>’ custom in Thailand includes a food taboo known as <i>kalum</i>.This paper intends to describe the unknown details of parturient women's traditional taboos in northeast Thailand.<br><b><big>Methods</big></b><br>Ethnographic semistructured interviews in the Thai language were conducted in February 2006 with 10 women in northeast Thailand who had babies ranging in age from newborn to 6 years. <br><b><big>Results</big></b><br>The purpose of <i>Yu fai</i> is to enable a mother who has recently undergone parturition to recover her pregestation physical and mental conditions following childbirth. Some new mothers will complain of bad health if they fail to apply <i>Yu fai</i>. Certain food taboos and recommendations are part of the <i>Yu fai</i> practice, and each has a specific context based on traditional beliefs.<br><b><big>Conclusions</big></b><br>The three objectives of <i>Yu fai</i> are identified as follows: to recover the mother's body to its usual pregestation condition; to enable sufficient breast milk or the capability for future pregnancies; to endure a long and healthy life. Applying <i>Yu fai</i> will influence a mother's lifetime health conditions after childbirth. Each of the prohibited or recommended food items is the result of specific contexts based on traditional beliefs. However, <i>Yu fai</i> is now changing, along with urbanization and improved communications, even in the rural areas of northeast Thailand.