Effects of Low-Dose Leptin on the Metabolic/Behavioral Phenotypes of the Formerly-Obese

We demonstrated a substantial metabolic resistance to maintenance of altered body weight. Leptin is secreted by fat cells in circulating concentrations that are directly proportional to fat mass. Leptin-deficiency is associated with severe obesity in rodents and in humans and the obesity is relieved by leptin administration. These studies examine the hypothesis that some of this metabolic opposition cto the maintenance of an altered body weight can be relieved by restoring circulating concentrations of the hormone leptin to the same range as at usual body weight in subjects who are maintaining a reduced body weight. The basic design of this study is to observe subjects at a 10% reduced body weight and then again at that reduced body weight while receiving physiological leptin or T3 supplementation.