Environmental changes to promote a healthy diet, physical activity and breastfeeding, such as those addressing roads, sidewalks, housing, parks, businesses, urban sprawl, and lactation accommodation, can have a significant effect on the health of the community. These environmental locales are also referred to as the “built environment.” Advice to breastfeed our babies or to eat well and exercise often does not take into account that the environment may not be conducive to these healthy activities. However, numerous organizations and authors have identified environmental changes as the most promising strategy for creating population-wide improvements in nutrition and physical activity. By addressing these specific environmental approaches, Maternal, Child, and Adolescent Health (MCAH) programs have a unique perspective and role in tackling the rise of chronic diseases such as obesity and diabetes as outlined in the state obesity plan. Specifically, MCAH can be change agents in improving the nutrition, physical activity, and breastfeeding environments in California.