BACKGROUND: The concept of 'early life programming' considers the importance of very early environmental exposures throughout the gestational period on the subsequent health outcomes of offspring. The role of maternal dietary intake, specifically, has been highlighted after recent studies have shown maternal diet quality to predict mental health problems in offspring. Even in the pre-conception period, maternal nutrition can have permanent and sustained phenotypic consequences for offspring. DISCUSSION: Here, we consider these findings in the context of the primary prevention of mental disorders and argue that interventions that target maternal diet could be of significant value. SUMMARY: It is clear that, in order to reduce the burden of mental health issues across the lifespan, urgent action is required, particularly in the field of prevention. We thus call for the application and evaluation of targeted, primary prevention strategies that focus on dietary intake with the view to improve mental health outcomes of mothers and offspring during the postnatal period and beyond.