As a weight loss surgeon, I can tell you simply eating less is not the key to losing weight. The biology of a person is set to prevent starvation. When you eat less, your brain interprets the behavior as starvation. We do know that the lap-band, properly placed and properly adjusted, will produce a change that keeps the brain from interpreting new eating habits as starvation.
There is a fundamental reason that diets don’t work in the long run. The thermostat for appetite, and for fat storage, lies in the upper part of the stomach, about the spot where we place the lap- band. When food passes by this part of the stomach, it sends a signal to the part of the brain you have no conscious control over, and your appetite is dimmed.
One hormone that regulates appetite is called ghrelin. Before you eat a meal, ghrelin levels rise, and that rise is the appetite signaling your body that it is time to eat. The best suppression of appetite comes from food. If you eat a large amount of food, the level of ghrelin decreases, and your appetite is diminished. If you were injected with ghrelin, even if you just ate a large meal, you would be ravenous.
The mechanism of ghrelin regulation, as well as other appetite hormones, comes from the brain, in an area called the hypothalamus. You have no control over this part of the brain, and no amount of “willpower” will cause it to change. The nerves in the upper stomach send a signal to the hypothalamus. In response to this signal, the hypothalamus sends out a hormone called pro-opiomelanocortin (POMC). This causes a suppression of ghrelin, and ghrelin levels go down.
If the upper part of the stomach has less food passing through it, when you are in a famine, or on a diet, or between meals, the hormone levels of ghrelin begin to rise, and you will become hungry, and your body will drive you to eat. In this case, the lack of food passing by that part of the stomach triggers the hypothalamus to send out a hormone called Neuropeptide Y which causes an increase in the level of ghrelin.
When you are on a diet, you eat less, less food passes by the top part of your stomach, and you become hungry. Think about how you felt when you tried Lean Cuisine, or Jenny Craig, or Nutri-system meals. Two hours later, what did you notice? You were hungry.
After hosting countless seminars on weight loss surgery over the years, the most consistent question asked by patients has been “Why did I fall off of my diet?” The answer is always the same: hunger.
The lap-band solves this problem. With the lap-band positioned in this portion of the stomach, and properly adjusted, eating a small amount of food will amplify the signal from the stomach to the brain. This allows the brain to think you have eaten more than you have, and thus inhibits ghrelin (and other appetite stimulating hormones). That means instead of getting hungry by eating a small amount of food, the appetite is greatly diminished.