The goal of this dissertation is to quantitatively account for the negative relationship between body mass and socioeconomic status observed among women in the U.S. Almost 1 out of 3 white women in the U.S. are currently obese, and data from the National Longitudinal Survey of Youth 1979 (NLSY79) show that, at age 30, obese women have completed almost 1 fewer school grade, are less likely to participate in the labor market, and if they work they have wages that are lower by 17%; they are more likely never to have been married and, if they are married, their spouses have earnings that are lower by 27%. I interpret these facts taking into consideration that not only body mass may affect labor- and marriage-market opportunities but also (a) behavioral factors, potentially influenced by schooling attainment and family income, play a key role in the accumulation of body weight; and (b) women may be heterogeneous in terms of their propensity to gain weight on the one hand and labor- and marriage-market endowments on the other hand. To this end, I specify and estimate a dynamic model in which (a) wage and spousal income offers, as well as the arrival probability of marriage offers, depend on body mass; and (b) women make decisions about their body mass, labor market participation, and marital status over the life cycle. I exploit the estimated model to quantify the consequences of women\u27s body mass in the labor and marriage markets and answer the following questions: (a) How responsive is body mass behavior to labor- and marriage-market incentives? (b) What fraction of the cross-sectional variation in body mass is explained by characteristics formed prior to leaving school? (c) What is the effect of schooling attainment on body mass and through which pathways does this effect unfold over the life cycle? (d) How effective in preventing adult obesity would be policies aimed at eliminating excess weight at the time of school leaving?