Leptin is reponsible for our weight

In papers published in the journal Science, two research teams describe newfound powers of leptin, the mysterious hormone that helps govern hunger and satiety. It appears that the substance, produced by fat cells, plays a crucial role in establishing the brain's circuitry before birth, and retains the ability to subtly rewire those neural connections throughout life.

Those observations, made in mice but which scientists believe may also apply to humans, offer a peek at the cellular workings of one of life's few essential impulses: the drive to eat. The papers also shed light on why many people seem to have a physical "set point" - a weight their body seeks to maintain despite their efforts to change it, report washingtonpost.com

Leptin is a hormone. This hormone affects our weight and our appetites. It also helps wire up the brain in a way that decides whether we are going to be fat or slim. This wiring up of the brain, it seems, sets up our eating and weight patterns for our whole lives.

What interests scientists and many health professionals is whether leptin may be manipulated to help people, especially overweight people, to lose weight and not put it back on. Would this research bring us a step closer to re-wiring our brains if they were not wired in the way we wanted right from the beginning?

These studies and their findings will help us understand why it is that what we eat when we are very young can affect many aspects of our health, weight and metabolism later on in our lives. What a mother eats when she is pregnant could have a bearing, apparently, on how the baby’s health develops, inform medicalnewstoday.com

According to channelnewsasia.com when it was discovered in 1994, leptin thrilled scientists because it seemed so basic to obesity and appetite.

Overweight rodents fed leptin lost weight and studies quickly showed that some overweight people had unusually low levels of the hormone.

But leptin's effect was not so straightforward in humans, and it became clear that simply injecting obese people with it was not going to make them lose weight.

In a second study, scientists at Oregon Health & Science University found exposure to leptin early in life affected brain structures involved in weight regulation.

Also working with mice, they tracked development of neurons in a part of the brain called the arcuate nucleus of the hypothalamus.

Brain circuits there were less developed in mice genetically engineered to compare mice with no leptin and normal mice.

Injecting baby mice with leptin restored normal brain structure, they found.