Overnutrition-induced obesity and metabolic dysregulation are considered major risk factors contributing to breast cancer. The origin of development of obesity and breast cancer can retrospect to early fetal life. Maternal diets or nutritional status may affect early-life disease programming resulting in prevention of human diseases in adult life of the offspring. Our study focuses on studying the effects of maternal bioactive dietary components on early-life prevention of obesity and breast cancer, and exploration of potential epigenetic mechanisms during these processes. In this seminar, I will discuss the effects of bioactive dietary phytochemicals on epigenetic modulation, and how these maternal diets help to migrate later-life risks of obesity and breast cancer in the offspring through regulation of host epigenetics, metabolism and gut microbiome.