RESUMEN
Latin America has notably elevated rates of adolescent fertility and obesity in women. Although numerous studies document associations between adolescent fertility and obesity across the life course, the pathways explaining their association are insufficiently theorized, especially regarding the factors in Latin America that may underpin both. Additionally, much of the existing research is from high-income countries, where fertility and obesity are trending down. In this paper, we review the various complex pathways linking adolescent fertility and obesity, highlighting research gaps and priorities, with a particular focus on Latin American populations. We carefully consider pregnancy's distinct impact on growth trajectories during the critical period of adolescence, as well as the cumulative effect that adolescent fertility may have over the life course. We also articulate a pathway through obesity as it may contribute to early puberty and thus, to adolescent fertility. If obesity is a cause of adolescent fertility, not a result of it, or if it is a mediator of early-life exposures to adulthood obesity, these are critical distinctions for policy aiming to prevent both obesity and early fertility. Research to better understand these pathways is essential for prevention efforts against obesity and undesired adolescent fertility in Latin America.