[3], [10], [11] One US study analysed serum hepcidin and reported it to be significantly higher in bariatric surgery candidates compared to non-obese women. [3] Severe obesity however, is frequently associated with comorbidities (e.g. obstructive sleep apnoea, gastro-oesophageal reflux and fatty liver disease) that influence haematological markers or increase blood loss, [5], [12], [13] and findings from this study may not be applicable to the wider population of less severely obese young women who are not burdened with comorbid conditions. This evidence concerns the gene HAMP and obesity disorder.