This study conducted the first nationwide epidemiological survey to investigate the effects of dietary fat, fruit, and vegetable intake on the health of student musicians in the United States. Despite the recognized importance of nutrition in other performance fields, such as athletics, the relationship between diet and health in musicians has not been rigorously explored until now. The survey assessed dietary intake, body mass index (BMI), mood states via the DASS-21, engagement with healthcare, nutritional knowledge, and mental health history among 641 music majors. Key findings include higher fat intake and BMI predicted higher DASS-21 total scores as well as each separate sub-score for depression, anxiety, and stress; a significantly lower mean BMI in the study group compared to the general U.S. college student population; and mixed results regarding healthcare engagement and its relation to diet and BMI, suggesting the need for a more suitable model for analysis. Notably, sources of nutritional knowledge and barriers to healthy eating significantly influenced diet quality, indicating potential misinformation about fat consumption and the positive impact of accessible healthy foods on diet quality. Additionally, mental health diagnoses were associated with lower fat and fruit/vegetable scores but not BMI. These results underscore the potential negative impact of dietary habits on mental health among music majors and highlight a widespread misunderstanding of what constitutes a healthy diet. Future research should refine dietary assessments and incorporate biometric data, while music education institutions are urged to include nutrition education in their curricula, emphasizing the role of diet in overall musician wellness.