Diet‐induced Obesity Decreases Liver Iron Stores in Mice Fed Iron Deficient, Adequate or Excessive Diets

Abstract

Epidemiological and observational evidence suggests that obesity is related to poor Fe status. To determine interactions between obesity, dietary Fe intake and Fe status, male weanling C57BL/6J mice were fed either standard or high fat diets (3.8 vs 4.5 kcal/g) for 16 weeks to produce lean or obese phenotypes. Fe concentrations of both the high fat or control diet were set at 5, 50 or 500 mg Fe/kg diet. Mice fed the high fat diets had a significantly higher percentage body fat (17.9%) compared to mice fed control diets (5.3%, P < 0.001). Dietary Fe levels alone did not significantly influence body composition. Dietary Fe intake did not differ significantly between mice fed high fat or control diets matched with the same Fe concentrations. Obesity and/or dietary Fe concentration did not significantly affect plasma Fe levels. ANOVA analysis showed significant effects of diet‐induced obesity, dietary Fe and an interaction between both factors on liver Fe levels (P < 0.05). Obese mice had significantly lowered liver Fe levels compared to lean cohorts fed the same amount of dietary Fe (P < 0.05 for all comparisons). Moreover, lean mice fed the 5 mg Fe/kg diet had similar liver Fe levels (127 mg Fe/kg ± 0.04) compared to obese mice fed 50 mg Fe/kg diet (132 mg Fe/kg ± 0.05). These data suggest that obesity, independent of dietary Fe intake, influences liver Fe stores.