Third, transgenic mice overexpressing Lcn2 in osteoblasts displayed less food intake, reduced fat mass, body weight, and lower fed and fasting glucose level; more insulin sensitivity; and greater energy expenditure throughout life indicates that prolonged exposure to increased levels of LCN2 does not lead to obesity and also does not cause resistance to the beneficial effects of LCN2.24 This evidence concerns the gene LCN2 and obesity due to melanocortin 4 receptor deficiency.