Focus groups with 31 Black and Hispanic men with localized prostate cancer and their partners identified four key barriers to adopting heart-protective diets like the Mediterranean diet: attitudes toward healthy eating and medical advice, family and cultural influences, emotional and spiritual factors, and structural obstacles affecting confidence in dietary changes. The research highlights that family buy-in emerges as the most critical factor for successful dietary modification. This finding challenges the traditional individual-focused approach to nutrition counseling in oncology. Given that cardiovascular disease kills more men with localized prostate cancer than the cancer itself, addressing dietary barriers becomes particularly urgent for underserved populations who face disproportionate cancer mortality. The study's emphasis on partner engagement and cultural tailoring represents a necessary evolution in cancer care delivery. However, the qualitative methodology and small sample size limit generalizability. The research provides a foundation for designing more effective dietary interventions that acknowledge the complex social, cultural, and structural realities facing medically underserved cancer survivors, potentially improving both cancer and cardiovascular outcomes in these vulnerable populations.