Comparative Analysis of Diet Quality, Iron Intake, and Supplementation Among Vegan and Omnivorous Amateur Runners Living in Urban Areas

Food Sci Nutr. 2026 Jul 9;14(7):e72088. doi: 10.1002/fsn3.72088. eCollection 2026 Jul.

Abstract

Plant-based diets, including vegan and vegetarian patterns, are gaining popularity among physically active individuals, including amateur runners. While such diets may offer health benefits, they also carry a risk of inadequate intake of key nutrients, among which iron plays a crucial role. This study compared diet quality, iron intake, and dietary supplementation among vegan, lactovegetarian, and omnivorous amateur runners in Warsaw, Poland. One hundred runners (52 males, 48 females; aged 18-65) were classified into vegan (n = 36), lactovegetarian (n = 10), and omnivorous (n = 54) groups. Dietary intake was assessed via Food Frequency Questionnaire (FFQ) and IRONIC-FFQ for iron, and diet quality was measured by the Pro-Healthy Diet Index (pHDI). Nutritional knowledge was assessed using a 10-item test, and supplement use was evaluated via proprietary self-reported questionnaire. Group differences were evaluated with ANOVA, t-test, and Kruskal-Wallis test. Pearson's χ 2 tests and Spearman correlation were also performed. No significant differences in age, Body Mass Index (BMI), height, or weight were found across groups. Plant-based runners had higher median iron intakes (VEG: 20.5 mg/day; LOW: 19.97 mg/day) than omnivores (OMN: 13.21 mg/day, p < 0.001). pHDI was highest in the LOW group (31.82), followed by VEG (25.57) and OMN (24.76), with no significant sex differences. Supplement use was more frequent in plant-based groups (VEG: 91.7%, LOW: 90.0%, OMN: 63.0%, p = 0.004); vitamin B12 and D were most common. Nutritional knowledge was significantly greater in VEG and LOW groups versus OMN (p = 0.002). Iron intake correlated positively with nutritional knowledge (p = 0.014), while pHDI correlated negatively with BMI (p = 0.002). Well-planned plant-based diets supported adequate iron intake and diet quality in amateur athletes, with increased supplement use and nutritional awareness mitigating deficiency risks. Nutrition education and individual nutrition planning are advised for all athletes, with attention to iron status, especially in female runners.