Pregnancy fasting poses a paradox: why would a woman restrict her diet during a period of increased nutritional need? This qualitative, cross-sectional study applied biological and cultural evolutionary theories of pregnancy diet to emic models of fasting with the aim of establishing a testable biocultural framework of pregnancy fasting. The research took place with Muslim women residing in Mysore, India. In-depth interviews were conducted with pregnant women who have experience and knowledge of fasting during during the holy month of Ramadan. Our findings indicate that pregnancy fasting is socially acquired via multiple modes of transmission and that women do not fast according to mainstream evolutionary theories of pregnancy diet, but perhaps to gain moral capital.