The respective prevalences of both asthma and obesity have seen a significant rise in the past few decades. Although the association between these 2 conditions has been found in many studies from different areas around the world, the exact mechanisms for how this association arises remains unresolved. Because both asthma and obesity appear to have their beginnings in early childhood, common exposures that predispose individuals to both these conditions may explain how they are associated. These exposures include common genetic predictors, prenatal exposure to specific nutrients and overall maternal nutrition, patterns of colonization of the neonatal and infant gut, birth weight and infant weight gain, sedentary behaviors, and levels of adipokines in early life.