MPO and obesity due to melanocortin 4 receptor deficiency: The contradictory results of our study, which showed a positive association of Rb with MPO and a negative one with oxLDL, may be partially explained by the lack of adjustment for dietary intake of Rb (not provided in nutrient analysis) or by other unpredictable confounders since the exact mechanism of Rb’s role in obesity has not yet been fully elucidated.