Leptin promotes nerve growth in fat cells

[corybroo]

MedicalXpress has an article How neurons reshape inside body fat to boost its calorie-burning capacity that reports that leptin can regulate the presence of neurons in both white and brown fat.

What really ignites the breakdown of stored fat molecules are nerves embedded in the fat tissue … If they receive the right signal, they have an astonishing capacity to grow.  That signal is the hormone leptin, which is released by the fat cells themselves.

the researchers found that the normally bushy network of neural fibers within fat tissue shrinks in the absence of leptin and grows back when the hormone is given as a drug.

we did not expect to find this profound level of neural plasticity in an adult,

[Leptin] relays signals between fat deposits and the brain, allowing the nervous system to curb appetite and boost energy expenditure to regulate body weight. When mice are genetically engineered to stop producing leptin, they grow three times heavier than normal mice. They eat more, move less, and cannot survive in what should be tolerable cold because their body can't properly utilize fat to generate heat.

Give these mice a dose of leptin, however, and they quickly begin to eat less and move more. But when the researchers treated them longer, for two weeks, more profound changes occurred: the animals started to break down white fat, which stores unused calories, at normal levels, and regained the ability to use another form of fat tissue, brown fat, to generate heat.

[Ron Put]

It's not so simple.  I believe that there are several threads here which have discussed leptin, but just popping extra leptin may in fact be counterproductive.

Obese people have more leptin than healthy people:

Serum immunoreactive-leptin concentrations in normal-weight and obese humans

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It's not how much leptin you have in your body, but how your brain interprets its signals:

Mechanisms of leptin action and leptin resistance