Obesity and Thyroid Disorder Even though an under-active thyroid may lead to weight gain and even obesity, in some cases, there is evidence that obesity itself can potentially lead to thyroid dysfunction. Since weight loss frequently will lead to a normalization of the TSH, there is evidence that an increased TSH can be a consequence of obesity. The abnormality of thyroid hormones is responsible for weight gain since they control body metabolism. Several studies have reported a positive correlation between increased BMI and thyroid conditions. It is clear that hypothyroidism can cause obesity, but the phenomenon of how obese people are more prone to thyroid-related conditions is still not well understood. Another factor that can be the link between obesity and thyroid disorder is the leptin-a starvation hormone (the hormone made by adipose cells which also influences TSH release). Leptin a hormone that is produced by adipocytes (fat cells) regulates the energy balance by...