2025 study on the diet quality of ultra-marathon runners: https://pmc.ncbi.nlm.nih.gov/articles/PMC11820624/
From the discussion section, "It is important to note that inadequate intake in the athletes of the present study may carry significant negative health implications. Insufficient consumption of fruits and wholegrains has been linked to the development of chronic diseases, including CVD, cancer, T2D, and hypertension. Additionally, high intake of sodium, saturated fat and discretionary food items are correlated with higher incidence of obesity, T2D, CVD, dementia, and cancer. Paradoxically, despite exceeding the WHO guidelines for physical activity by a substantial margin, these athletes are not meeting dietary recommendations essential for long-term health, highlighting the potential risks posed by these inadequacies."