ABSTRACT
Reproduction is an energetically expensive enterprise, and its costs are largely borne by females. Across species, females spend approximately 3.5 times more energy than males in gamete production [1]. Energy costs are magnied once pregnancy is achieved. The estimated energetic cost of a human pregnancy with adequate gestational weight gain is approximately 78,000 kcal [2]. From that point forward, costs associated with lactation and childrearing further tilt the energy expenditure balance toward women. An in-depth discussion of the evolution of human reproductive traits, in general, and of ovulation in particular, is outside the scope of this chapter. However, it will be useful to our discussion of the role of nutrition on ovulatory function to keep in mind that the massive energetic costs of reproduction likely exerted enormous evolutionary pressure in selecting reproductive systems capable of sensing adverse environments to prevent pregnancy in conditions of insufcient energy availability.
