Understanding Obesity and the Hormones Involved

Getting It Right. Confessions of a "Desk Dumpling"

A lot is known about what causes obesity. The simplest explanation is that the genes that have protected us from famines for millions of years are at the core of the cause of obesity. These powerful biochemical systems are centered on a small area in the middle of the brain called the hypothalamus. A specialized area in the hypothalamus, called the arcuate nucleus, is where the signals that control metabolic rate, hunger and satiety are located.

The two major hormones that control the hunger and satiety cells are ghrelin and leptin. Ghrelin is produced by the stomach and travels to the brain where it turns on the hunger cell and turns off the satiety cell. Leptin is produced by the fat cells of the body and travels to the brain where it turns on the satiety cell and turns off the hunger cell. When you are obese you have lots of fat cells and thus your leptin levels are high. The high leptin levels in combination with high insulin levels turn off the stomach cells that make ghrelin so your ghrelin levels are low. Now if that seems backward, you are right. The problem is that high leptin levels over time make the satiety cell insensitive to leptin and low ghrelin levels make the hunger cell hypersensitive to ghrelin. The result is that even though the leptin levels are high and the ghrelin levels are low, the hunger cells are turned on and the satiety cells are turned off.

This is exactly the situation that occurs in a famine, hunger cells on and satiety cells off. So if you are obese, even though you have plenty of fat stores, the brain behaves like you were starving. A common sign of this is that most obese people don't feel hungry when they get up in the morning. As a result they often skip breakfast. The brain interprets this as more starvation signals and further shuts down the metabolism. In fact the number one risk factor for obesity is skipping breakfast.

Ghrelin is also important in many other functions of the body. One of the most important is sleep. In order to efficiently progress though the normal cycles of sleep you need adequate ghrelin levels. You will not sleep as efficiently; you will dream less and get less restorative sleep. This will make you more tired the next day and since dreaming promotes leptin production, you will be hungrier and have a lower metabolic rate. The imbalance of leptin and ghrelin are at the heart of the cause and consequences of obesity.

Desk Dumpling you say, "What is that?" A desk dumpling is what many of us are turning into as we spend time in front of computers. Not all of us are Couch Potatoes. I work from a home based office and therefore find myself spending enormous hours in front of my computer. I found myself, like so many today slowly packing on the pounds, fat and inches. I would go through a cycle of losing inches and pounds and then next thing I knew it would yo-yo back on. One day I look in the mirror and it was like all this extra weight would magically appear overnight. I, like many needed to figure out what was going on with this body. I used to be a "female jock." I was not totally inactive, after all, I love to walk. Isn't walking and exercise what they say I need? I ate a great diet (not junk) BUT it didn't matter, I kept expanding. I needed to understand the mechanisms of obesity and then I needed some tools to help me overcome a problem that was getting more severe as the years and the decades rolled by. I now have the tools and an understanding of what I need to do, The Desk Dumpling is working her way back to becoming a Desk Jock. I hope this will help you?