Young adults are a highly desirable target population for energy-dense, nutrient-poor (EDNP) food and beverage marketing. But little research, resources, advocacy and policy action have been directed at this age group, despite the fact that young adults are gaining weight faster than previous generations and other population groups. Factors such as identity development and shifting interpersonal influences differentiate young adulthood from other life stages and influence the adoption of both healthy and unhealthy eating behaviours. EDNP food and beverage marketing campaigns use techniques to normalize brands within young adult culture, in particular through online social media. Young adults must be a priority population in future obesity prevention efforts. Stronger policies to protect young adults from EDNP food and beverage marketing may also increase the effectiveness of policies that are meant to protect younger children. Restrictions on EDNP food and beverage marketing should be extended to include Internet-based advertising and also aim to protect vulnerable young adults.