Which hormones are primarily associated with obesity?

Leptin and ghrelin play central roles in the regulation of appetite and energy balance, making them key hormones associated with obesity. Leptin, produced by adipose (fat) tissues, signals to the brain the status of energy reserves, helping to inhibit appetite and increase energy expenditure when fat stores are sufficient. In contrast, ghrelin, known as the "hunger hormone," is produced in the stomach and stimulates appetite, signaling to the brain that it is time to eat. In individuals with obesity, there can be disruptions in the signaling of these hormones, leading to increased hunger and reduced energy expenditure, which can perpetuate weight gain and make it difficult to lose weight.

Other hormone pairs such as insulin and cortisol have connections to obesity but are primarily involved in metabolism and stress responses, respectively. While adrenaline and serotonin impact various aspects of mood and metabolism, they do not directly regulate appetite as leptin and ghrelin do. Similarly, estrogen and testosterone influence body fat distribution and metabolism but are not primarily responsible for the mechanisms of hunger and satiety like leptin and ghrelin. Thus, the role of leptin and ghrelin in appetite regulation and energy homeostasis directly relates them to the development and maintenance of obesity.