The problem is that overweight people have large amounts of leptin, but their brains are not receiving a significant signal to stop eating. But, why does the brain not understand it ?, This phenomenon is called "resistance to leptin" . This is similar to insulin resistance. Threshold levels of this hormone may continue to rise as people gain weight.
Does leptin work as a treatment for obesity?
With the latest understanding of leptin resistance, it makes no sense to give people leptin if they have an altered response to it . Lustig says. "Leptin resistance is there, no amount of leptin is going to overcome that resistance."
This hormone only helps in a few extremely rare cases in the world where people barely produce leptin, causing them to overeat and become obese. When those people received leptin by injection, they stopped overeating and lost weight. But for the vast majority of people, the treatment will not work, nor is it approved as a medical treatment for weight loss.