The hepatic manifestations of obesity are clear in the present model as the obesogenic phenotype of the HFD-obese rats (marked weight gain, hyperglycemia, insulin resistance, dyslipidemia, elevation in the circulatory TNF-α and leptin levels and a marked decline in the adiponectin level) is associated with histological changes in the liver and significant elevation of serum activities of the transaminases and bilirubin level. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.