24 Sep “We all have a leptin floor; the problem is
Do They Work for Obesity Weight Loss
cheap moncler jackets It’s been called the “obesity hormone” or “fat hormone” but also the “starvation hormone.” When scientists discovered leptin in 1994, excitement arose about its potential as a blockbuster weight loss treatment. Even today, the Internet is loaded with sites that sell leptin supplements. Any truth to those pitches? And what exactly is leptin? cheap moncler jackets
WebMD asked two experts on leptin to discuss how this hormone affects weight and appetite, as well as other aspects of health.
“Leptin is not our obesity hormone. Leptin is our starvation hormone,” says Robert H. Lustig, MD, professor of pediatrics at the University of California, San Francisco and a member of the Endocrine Society’s Obesity Task Force.
Leptin is a protein that’s made in the fat cells, circulates in the bloodstream, and goes to the brain. “Leptin is the way your fat cells tell your brain that your energy thermostat is set right,” Lustig says.
moncler sale outlet “Leptin tells your brain that you have enough energy stored in your fat buy moncler jackets cells to engage in normal, relatively expensive metabolic processes,” he says. “In other words, when leptin levels are at a certain threshold for each person, it’s probably genetically set when your leptin level is above that threshold, monclerdownjacket your brain senses that you have energy sufficiency, which means you can burn energy at a normal rate, eat food at a normal amount, engage in exercise at a normal rate, and you can engage in expensive processes, like puberty and pregnancy”. moncler sale outlet
cheap moncler jackets sale But when people diet, they eat less and their fat cells lose some fat, which then decreases the amount of leptin produced. cheap moncler jackets sale
moncler outlet uk “Let’s say you starve, let’s say you have decreased energy intake, let’s say you lose weight,” Lustig says. “Now your leptin level goes below your personal leptin threshold. When it does that, your brain cheap moncler coats senses starvation. That can occur at any leptin level, depending on what your leptin threshold is.” moncler outlet uk
“Your brain senses that and says, ‘Hey, I don’t have the energy onboard that moncler outlet sale I used to. I am now in a starvation state,'” Lustig says.
Then several processes begin within the body to drive leptin levels back up. One includes stimulation of the vagus nerve, which runs between the brain and the abdomen.
moncler factory outlet “The vagus nerve is your energy storage nerve,” Lustig says. “Now the vagus nerve is turned on, so you get hungrier. Every single thing the vagus nerve does[is] designed to make you take up extra energy and store it in your fat. Why? To generate more leptin so that your leptin can re establish its personal leptin threshold. It causes you to eat and it causes you to get your leptin back to where it belongs.” moncler factory outlet
moncler outlet online Q. How does leptin affect weight moncler outlet online
“Here’s the question: If this thing works like a thermostat an adipostat why do we keep gaining weight?” Lustig says.
The problem is that overweight people have large amounts of leptin, but their brains aren’t getting the important signal to stop eating.
cheap moncler coats “How cheap moncler outlet come the brain doesn’t get it? That cheap moncler phenomenon is called ‘leptin resistance,'” says Lustig, who has done research on the moncler outlet subject. Leptin resistance is similar to insulin resistance in type 2 diabetes, in cheap moncler sale which the pancreas produces large amounts of insulin, but the body doesn’t respond to it properly. cheap moncler coats
moncler jackets outlet Leptin levels can keep going higher as people get fatter. “We all have a leptin floor; the problem is, we don’t have a leptin ceiling,” Lustig says. moncler jackets outlet
moncler sale “In leptin resistance, your leptin is high, which means you’re fat, but your brain can’t see it. In other words, your brain is starved, moncler sale outlet while your body is obese. And that’s what obesity is: it’s brain starvation.” moncler sale
moncler outlet sale Not only is leptin part of the hunger system, it’s also part of the reward system, Lustig says. “When your leptin levels moncler outlet online are low, food is even more rewarding. When your leptin levels are high, that’s supposed to extinguish the reward system so that moncler mens jackets you don’t need to eat so much, and food doesn’t look nearly as good.” moncler outlet sale
cheap moncler But in leptin resistant people, the reward system doesn’t cue a person to stop eating when leptin levels rise, Lustig says. “The leptin is being made by the fat cells, the fat cells are trying to tell the moncler sale brain, ‘Hey, I don’t need to eat so much,’ but the brain can’t get the signal. You feel hungrier and the reward doesn’t get extinguished. It only gets fostered, and so you eat more and you keep going and it becomes a vicious cycle. If your brain can’t see the leptin signal, you’re going cheap moncler jackets to get obese.” cheap moncler
cheap moncler outlet Q. Can leptin work as an obesity treatment? cheap moncler outlet
moncler jacket sale That was the great hope after leptin’s discovery in 1994, says Richard Atkinson, MD, an endocrinologist, obesity expert, and clinical professor of pathology at Virginia Commonwealth University. moncler jacket sale
According to Atkinson, mouse experiments that began in the early 1970s pointed to “some sort of a hormone that affected food intake and body fat, but [scientists] didn’t know what it was.”
moncler outlet jackets When researchers finally discovered leptin in 1994, it helped “put obesity on the map because it suggestedobesity may have some physiological basis, instead of just being, “fat people can’t keep their mouth shut,'” Atkinson says. “For those of us in the field of obesity, it was a watershed moment. Suddenly, everybody jumped on the bandwagon. This became a frantic obsession with the obesity community, at least.” moncler outlet jackets
Many scientists explored leptin as a possible treatment for obesity; they believed that if people were leptin deficient, giving them leptin would raise levels, which would signal them to stop overeating. “But when you started giving it to people, it didn’t work so well,” Atkinson says.
“This stuff is made by fat tissue, and as you get fatter, you make more of it. That was quite a shock because everybody thought that obese people were going to be deficient in leptin,” he says.
moncler outlet store With the more recent understanding of leptin resistance, it makes no sense to give people leptin if they have an impaired response, Lustig says. “The resistance is still there. No amount of monlcer down jackets leptin is going to overcome that resistance.” moncler outlet store
Giving leptin only helps in a few extremely rare cases in the world in which people make no leptin at all, which causes 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 moncler outlet people, the treatment won’t work, nor is leptin approved as a medical treatment for weight loss.
“Leptin is still sort of experimental. There’s no real need to take leptin now, unless you’re one of those very small probably 100 people in the world who doesn’t make leptin,” Atkinson says.