To say the adjustable gastric band (the band) works by making a person feel full when they eat less is not only simplistic, it is incorrect. We are just beginning to learn the complex regulation of appetite and fat storage. We know that simply eating less will not help a person to lose weight because the biology of a person is set up to prevent starvation. When you eat less, your brain interprets that as starvation. But we do know that the band, properly placed and properly adjusted, will change the brain so that it will not interpret eating less as starvation.
Learning how the band works may assist Lap-band surgery patients...
...to use it to their full advantage. Not learning correctly how the band works probably means you won't be able to lose the weight that you could.
There is a fundamental reason that diets don't work in the long run. If a person without the band eats the same amount of food that a band patient eats, the person without the band will not lose the same amount of weight and keep it off. There are exceptions to this. There are those who diet and keep their weight off for years, but those individuals are so rare you will probably read about them in the newspaper.
The thermostat for appetite, and for fat storage, lies in the upper part of the stomach above where we place the band. When this part of the stomach is stretched (when you eat a large meal), it sends a signal to a subconscious part of your and your appetite is dimmed.
Ghrelin - a hormone that regulates appetite
Before you eat a meal ghrelin levels rise, and that rise turns on the appetite, which signals your body that it is time to eat. To suppress your appetite you eat food. If you eat a large amount of food, the level of ghrelin decreases, and your appetite is diminished. To demonstrate this, if you were injected with ghrelin, even if you just ate a large meal you would be ravenous.
The mechanism of ghrelin regulation comes from the brain in an area called the hypothalamus. You have no control over this part of the brain, so no amount of "willpower" will cause it to change. Stretching the upper stomach stimulates nerves that send a signal to the hypothalamus. In response to this stretch, the hypothalamus sends out a hormone called pro-opiomelanocortin (POMC). This suppresses the appetite hormone ghrelin and its levels go down.
If the upper part of the stomach is not stretched, such as when you are in a famine, on a diet, or between meals, then the hormone levels of ghrelin rise and you become hungry, so your body drives you to eat. The lack of stretch causes 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, so you don't stretch the top part of your stomach and you become hungry. Think about when you tried Lean Cuisine, or Jenny Craig, or Nutri-system. Two hours later what did you notice? You were hungry.
I’ve been giving seminars about weight loss surgery for many years
When I ask patients why they fall off the diet, the answer is uniform - hunger.
The band solves this problem. With the band positioned below the portion of the stomach that controls appetite and is properly adjusted, eating a small amount of food will cause that part of the stomach to stretch, even a bit, and thus inhibit ghrelin release. That means the appetite is dimmed and you don’t feel hungry even if you only eat a small amount of food.
This is different, however, than "feeling full." Feeling full is a combination of abdominal wall strain, some gas in the small bowel, and a few other things. "Feeling full," means different things for different people. By suppressing this hormone, your appetite is dimmed. We can describe it this way: when you go to the supermarket while hungry you end up with a lot of food in your shopping cart that wasn't on your list. When you go to the super market after eating a meal, you get what is on your list and leave. Your appetite is dimmed, and food is less interesting to you. You may notice the same at home -- if you are bored, and you have not had a meal, you become quite interested in snacks. In contrast, if your appetite is dimmed, and you are bored, you tend to do other things (watch television, read, play on the computer, etc). Contrast this with times when your ghrelin levels are up, when your appetite is in full gear, and you go to the grocery store. You seem to find interest in every bit of food, and many things end up in your grocery cart that you did not have on your list (for me it is the ice cream section).
The second effect of stretching the upper stomach...
...is to release a hormone called leptin. Again, through the hypothalamus release of POMC, leptin levels rise. Leptin allows the body to better utilize fat stores. In this case, your body is saying, "we are in a time of plenty, we have a lot of food around here, it is okay to use fat stores if we need a boost of energy."
When you are on a diet, for example, you are not stretching the upper part of the stomach, because you are not eating enough food to fill your stomach. Or, if you are in a famine, or simply not eating, leptin levels decrease, preserving fat stores. Put another way, in order to preserve your life, the body holds on to fat as much as it can for as long as it can. Many dieters have seen this -- they diet (eat less) and after a bit of time their weight loss slows to a crawl. Even though they are eating far less than is required to maintain their body, they cannot lose weight. We also see this in band patients whose band needs a fill -- they continue to eat a small volume, but do not lose the weight that they should. Once the band is adjusted to allow the small volume of food to remain in the upper pouch, it stimulates the hypothalamus to increase the leptin and they lose weight again.
The regulation of appetite, fat storage, is far from these few hormones. There are more and complex mechanisms discovered. You have learned a bit of the regulation involved but there is no doubt that the key to feeling full is related to the nerves in the upper part of the stomach (and more than just the Vagus nerve).
This leads to the premise of this book: the Lap-band is elegantly simple
You need to put a small, measured volume of good food in your stomach three to four times a day. This will allow you to have your appetite dimmed and to lose weight. The key here is your active participation in this process, not just guessing at the number of calories that you are eating, but that you are measuring what you eat. Do not guess the amount and do not wait until you "feel full."
Successful patients do a few other simple things: they don't wash the food out of their stomach with liquids. They eat quality food, not junk.
Our goal is to help you work with your Lap-band to lose weight
Having the band is a journey: it is not an end in itself. Unlike any diet you have been on, or whatever gimmick you have bought—the decision to have a gastric band is the start of a journey, and unlike other programs, the band can provide biofeedback that will assist you to make the changes that are necessary for long-term healthy weight loss and maintenance. The band allows you to have a permanent lifestyle change.
Unlike a diet that you can "get off of" or "fall away from," the band provides the bio-feedback on an subconscious level that can assist your efforts to lose weight and live a healthier lifestyle.
We also learn from our patients. What are the successful habits of patients who get to their goal and stay there? What are the differences between those who get to their goal, and those who do not? The results of those studies are the work of this book. There is also some good news: patients who have not been successful in the past can find success once they begin to apply the principles in this book.