EXPERIMENTAL obesity produced by hypothalamic injury in various species of animals is uniformly accompanied with liver damage, progressing occasionally to cirrhosis.1 In hereditarily obese strains of mice, liver damage is also seen uniformly, and even tumors of the liver are observed.2 Although the increased incidence in human obesity of gall-bladder disease3 and diabetes mellitus4 has long been known, and although these conditions may lead independently to liver disease, there does not appear to be in the literature a consideration of the existence of liver damage in obesity per se. The majority of obese persons show a significant decrease in carbohydrate tolerance,5 and this impairment has been related to the duration rather than to the degree of obesity.6 Similar decreases in carbohydrate tolerance are observed in the experimental obesity of hypothalamic injury1 and in hereditarily obese mice.7 Newburgh and Conn8 suggested that the disturbed carbohydrate metabolism occurring with obesity is related