Biology Is Not Destiny - Part II

Continuation of Biology Is Not Destiny, Part I

2. Fat Cells = Hungry Baby Sparrows

Beyond genetics, overweight people have many more fat cells than people who have never been overweight. How many more? Overweight people can have four times as many of these hungry creatures (e.g., 160 billion versus 40 billion). Unfortunately, liposuction can only remove a few million of these - barely making a dent because fat is intertwined in our muscles and organs.

You can also develop more fat cells at any point in your life. And it doesn't take long to add fat cells. Some studies have shown that animals that are fed large amounts of high-fat food can permanently gain excess fat cells within one week.

Finally, once fat cells develop, they never disappear.

Why is this so important? Because excess fat cells promote very efficient storage of excess food as fat. Studies have traced where the body sends fat after eating. Apparently, for overweight and formerly overweight people, the body delivers fat into the fat cells more efficiently (perhaps directed by some of the biological devices described below). People who have never had weight problems seem to have more fat transported into muscles for use as more immediate fuel.

3. Hormones, Enzymes, and The Road Not Taken

There are a number of hormones and enzymes that evolution has established as biological barriers against weight loss. While it's not essential that you understand the mechanics of each one, the overall picture is daunting. We'll walk through them one by one to give you a sense of what you're up against.

Insulin

The concentration of blood sugar (glucose) in our bodies is regulated very carefully in people who are not diabetic. The body must maintain this regulation because the brain depends totally on blood sugar for its nutrition. And if our brains aren't properly nourished, we can't survive. This regulation is keyed by a detector in the brain that determines when blood sugar levels are too high or too low. Insulin, which is stored and manufactured in special cells within the pancreas, promotes the ingestion of glucose by our cells.

When people lose weight, the body's fat cells become especially sensitive to insulin. That enables the cells to absorb more nutrients at a faster pace. The muscle cells decrease their sensitivity to insulin, resulting in redirection of fat to the fat cells. Several studies have shown that some people develop an especially high level of insulin sensitivity when they lose weight; these people tend to regain weight very readily. It seems that a great many overweight people are quite sensitive to insulin and can very quickly store excess nutrients as fat partly because of this tendency. Most overweight people also have excessive amounts of insulin in their blood stream at all times, which may contribute to the efficiency with which their bodies become sensitive to insulin as they lose weight.

LPL

Lipoprotein lipase (LPL) is an enzyme (special chemical agent) produced in many cells. It stays on the walls of very small blood vessels and can become activated to transport fat in the body. During weight loss, increases in LPL occur as fat cells release their LPL into the bloodstream. By doing so, the fat cells send messages to the brain: "Get more food in us, now!"

Many Wellspring students have described this seemingly biological demand for food:

Biological Urges

When I used to go out to eat, people would often say, "You should try this; you should try that." Before coming to AOS, I would say, "Yeah, I'll try all kinds of things. Give it all to me!" If something was in front of me, I wanted to eat it all. It didn't matter what it was. It could never be enough. - Terry H.

My eating was really one big bad habit. I'd come home from school; sit down in the kitchen; turn on the TV; and do my homework with a bag of Chex Mix. It was completely automatic. If I got into a fight with my parents or something and they would go out to dinner, the second they walked out the door, I became a scavenger looking for something to eat. Anything I could get my hands on, I'd shove in my mouth. I'd look for a spoon and a jar of peanut butter and the whipped cream and anything and everything I could get my hands on. Even if I wasn't mad at them, I'd be like, "Oh well, they're not hounding me right now. I can shove everything in my mouth." - Lauren S.

Perhaps part of this drive to eat came from attempts to decrease eating occasionally, something that all AOS students did before coming to campus. Biologically, this means that weight loss stimulated hunger and helped convert food into stored fat. At least for some people, LPL activity is especially high and probably makes it more difficult for them to maintain weight loss.

Leptin

Leptin, a hormone discovered in 1994, is secreted by fat cells to act as a messenger between the cells and the brain, directing the amount of fat that gets stored in fat cells by affecting appetite. As fat cells shrink during weight loss, leptin is released by those cells. Increasing circulating levels of leptin can increase appetite and in turn contribute to weight regain.

Ghrelin

The hormone ghrelin is one of the strongest appetite stimulants known. It is produced in the stomach, which releases more ghrelin as people lose weight. For example, one study found that when weight controllers lost 17 percent of their body weight, their levels of ghrelin rose by 24 percent. Further substantiating the importance of ghrelin, weight loss surgery (such as the gastric bypass) decreases ghrelin substantially. With less appetite (due to decreased ghrelin), those who undergo these surgeries don't have to fight the ghrelin battle.

Adiponectin

Adiponectin is a protein secreted by fat cells (like leptin) that helps insulin direct blood sugar from the blood stream into your body's cells. When blood sugar goes into your cells it is stored or burned for fuel in those cells. Unfortunately, the more fat cells and larger fat cells a person has, the less adiponectin the fat cells secrete. This effect of adiponectin means that overweight people have a greater propensity to direct blood sugar into fat cells rather than using it for energy.

Between adiponectin, ghrelin, leptin, LPL, and Insulin, you can see that the body powerfully resists weight loss for overweight people.

4. Adaptive Thermogenesis

When weight controllers attempt to lose weight and reduce the amount of food they consume, their bodies have the capability to switch into a very efficient mode. Remember the plight of the hunter-gatherers, whose bodies we have inherited. In order for them to survive, their bodies had to make adjustments when they couldn't catch a deer in a particular week. Adaptive thermogenesis allowed their bodies to survive on fewer calories (greater efficiency, slower metabolism) during times when adequate amounts of food simply weren't available.

This means that reducing calorie intake by, say, five hundred calories a day may not promote any weight loss if the weight controller's body used adaptive thermogenesis to switch from its normal mode to a much more efficient mode. The good news about adaptive thermogenesis is that you can reverse this effect by moving more than usual or exercising every day. This exercise effect makes it possible for weight controllers to lose weight by bypassing the effects of adaptive thermogenesis (remaining in the relatively inefficient mode that burns more calories).

5. Set-point

As a weight controller tries to lose weight, his or her body uses adaptive thermogenesis to become efficient. The body also relies on its use of various hormones and enzymes (like insulin, leptin, LPL), to make it difficult to lose weight and keep it off. Fat cells themselves, including their unusual ability to expand in size and number, also contribute to this problem.

The set-point concept summarizes all of these effects, making it clear that weight controllers are stuck in bodies that utilize a variety of biological forces to resist weight loss. Just as leptin has been a recent discovery, undoubtedly there are other biological mechanisms that contribute to the body's desire to maintain an excessive amount of fat. Research with animals has shown that very overweight rats and mice show similar tendencies to "defend" (or "set") the amount of fat in their bodies at a very high level.

Unfortunately, part of this defense (or set-point) includes a tendency for the body of overweight people to respond more dramatically to the sight, smell and even the thought of tempting foods. A study by psychologists William Johnson and Hal Wildman at the University of Mississippi Medical School confirmed this. These researchers showed that overweight participants, compared to their lean counterparts, increased their insulin responses not only to the actual sight and smell of bacon and eggs, but to the thought of bacon and eggs. The overweight participants also salivated more when they saw or thought about tasty foods. This means that overweight people may defend their high weights by over-secreting insulin and digestive enzymes. These biological responses can increase the desire to consume more food in order to decrease the levels of these substances in the bloodstream.

Accepting the Biological Reality

Now, can you accept the fact that these biological factors create real and powerful resistance to weight loss for your child? It's not simply a question of willpower. Your child has definite biological challenges he or she will need to overcome, like every overweight and formerly overweight person. There is no escaping this reality. But your son or daughter can learn to manage his or her biological challenges effectively, like at AOS. As a famous diminutive Jedi master once said, "The force is within you."

When one of the Behavioral Coaches (therapists) at AOS explained these biological realities to Lauren S. she became quite upset, stunned at the power of it all. She said, "I can't believe it! All of my life people, including doctors, told me that my body was basically normal, fat but normal. Now you're telling me that I'm biologically abnormal and that this biology is the main cause of my weight problem? Why did I have to live the last ten years thinking that I was so pathetic? It's not just me or my personality, right? I really have to live with something that's a physical force within me."

Lauren's concerns are very legitimate. And when you think about it, the biology of obesity makes a lot of sense. Why would so many people have so much difficulty maintaining weight losses if biological forces did not resist weight loss? Losing weight produces many positive rewards, but relatively brief lapses in concentration (for example, binges and inconsistent exercising) are eagerly greeted by your body's extra billions of fat cells. That's a lot of hungry sparrows to feed! These fat cells and other biological forces are always present, ready to pounce.

Lauren had to learn to accept the powerful role that biology plays in creating and maintaining weight problems. Once she did, she could deflect some of the blame and shame away from her personality and self-esteem. We hope this chapter will help you do the same with your weight controller-to-be.

The challenge for Lauren and other AOS students is not to overcome "weak" and "pathetic" personalities. It's not a question of changing from an abnormal state of gluttony to a normal state of controlled eating. That would be much easier. Unfortunately, AOS students must change from a relatively normal state of functioning with an unfortunate biology to a set of behaviors that must be considered super-normal (i.e., beyond the norm, or extraordinary). This makes weight control one of the most difficult challenges a person can face.