Up to 35-45% of 25-44 year old Australian women and 50% of pregnant women are overweight or obese which is associated with elevated risk of chronic diseases such as cardiovascular disease (CVD), type 2 diabetes mellitus (DM2) and poor mental health. Reproductive-aged women present the population group at highest obesity risk due to longitudinal weight gain. This is related to factors including poor dietary intake, family and time commitments, physical inactivity and psychological exacerbation of excess food consumption. There are key life stages in reproductive-aged women where it is crucial to intervene to improve lifestyle behaviours and weight management. These include pre-conception and pregnancy. Pregnancy and postpartum life stages are commonly associated with weight gain, post-partum weight retention, and weight gain in the early parenting years. Obesity pre and during pregnancy and excess gestational weight gain are also associated with adverse pregnancy (eg gestational diabetes, preeclampsia), postpartum (post-partum weight retention, increased DM2 and CVD risk) and offspring (increased obesity and cardiometabolic risk) outcomes. There are also specific health conditions in reproductive-aged women which can confer additional adverse consequences of obesity such as polycystic ovary syndrome (PCOS) which affects up to 18% of Australian women with obesity-related consequences including infertility, type 2 diabetes and poor psychological health. Optimising weight management in reproductive-aged women is therefore a logical and critical public health strategy issue for reducing obesity-related morbidities. It is imperative to prevent the development of obesity at as an early stage as possible to reduce the risk of obesity-associated disease in women and their children.