In the present article, increased free thyroxine was found in obese subjects that decreased after weight loss in accordance with the hypothesis that the increase in TSH may represent a compensatory activation of the hypothalamus–pituitary–thyroid axis [11], while similarly, increased free thyroxine in obesity has been found in other studies [13].This activation appears to be mediated, at least in part, by the hypothalamic or pituitary effects of leptin [28]. Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.