Does breastfeeding prevent the metabolic syndrome, or does the metabolic syndrome prevent breastfeeding?

In mammalian physiology, lactation follows pregnancy. Disruption of this physiology is associated with long-term adverse maternal health outcomes, including higher risks of later-life obesity, type 2 diabetes, metabolic syndrome, hypertension, and cardiovascular disease. Multiple mechanisms likely contribute to these associations, including the metabolic demands of breastfeeding, modulation of stress reactivity, and confounding by other health behaviors. At the same time, evidence suggests that maternal metabolic health entering pregnancy affects lactation performance. In this paradigm, adverse lactation outcomes may be a marker for underlying maternal disease risk. Understanding these relationships has important clinical and policy implications for women's health.