Excerpt from Dr. Shapiro's Picture Perfect Weight Loss by Howard M. Shapiro, plus links to reviews, author biography & more

People who tend to be overweight have bodies that scientists would describe as efficient. At first blush, efficiency might sound like a good thing, but in the modern world, it's a liability. If your body uses food efficiently, you get the energy you need immediately, and then store the excess.

For some people, that's fine. Their bodies, almost mysteriously, don't store much of the food they eat. You know who I'm talking about—those few people who seem to be able to eat anything and still stay thin.

For the vast majority of us, however, the fat that we store just keeps hanging around. If only there were some way to reset the controls on our bodies. If we could do that, maybe we could turn the storage function from high to low.

Of course, as you know, scientists have not quite figured out a way. Until they do, some people will be more likely to gain weight than others. The reasons have to do with body chemistry.

On the other hand, that doesn't mean your body is going to fight you all the way. Many people can maintain a significant degree of weight loss, but that's easiest to do when you don't feel deprived.


Bon Hunger
For many years, we were fed the myth that there was a difference between genuine hunger and mere appetite. Hunger was supposed to be a good or normal sensation that came after prolonged periods without food.

For years, we believed the myth that you could actually tell the difference between appetite and hunger. Experts said that if you hadn't eaten food for hours and were genuinely hungry, you would know it. Dizziness, weakness, or acid stomach are the symptoms of real hunger.

Appetite, they claimed, was something different. Appetite was the result of out-of-control impulse. Your appetite, not hunger, made you head for a box of cookies despite the fact that you had just finished dinner. If you polished off a whole bowl of peanuts while chatting with your friend at the bar, that was the fault of your appetite again.

By this reasoning, the hunger-versus-appetite dichotomy was black and white. If you were legitimately hungry, that was okay. But if your appetite was making you eat, well, that was deemed less okay, even shameful.

Appetite, we were told, was an emotional response rather than a biological one. Appetite led you to eat out of boredom or frustration or anger. Eating for emotional reasons sounds like a wrong reason to eat.

But as scientists have begun to unlock the secrets of weight gain and weight loss, they have learned that people's reasons for eating can't be labeled in such neat and precise ways. The difference between hunger and appetite is hazy. Researchers have discovered that there are several hormones and neurochemicals in the body that have a profound effect on your life.


Listening to Your Chemicals
There are at least six body chemicals that have a profound effect on your life—and your weight. Their names are strange, and there's no reason to memorize them. But as weight-loss research continues, it's likely that you'll see these chemicals mentioned again and again. They are cholecystokinin, cortisol, dopamine, leptin, neuropeptide Y, and serotonin.

At the moment, there are no adequate explanations about how each of these affects your weight individually. What researchers do know, however, is that these substances relay messages to your fat cells, blood, brain, and intestines. They play a role in regulating body weight, appetite, eating behaviors, and even the way we think about food.

This is not to say that we are automatons programmed by chemicals. Our eating is also affected by other factors, from psyche to circumstances. Since the whole issue of eating is so complex, no researcher can tell you with absolute certainty why someone can resist the temptation of the bread basket one day but lust helplessly after chocolate cake the next day.

Reprinted from Dr. Shapiro's Picture Perfect Weight Loss: The Visual Program for Permanent Weight Loss by Dr. Howard M. Shapiro, Copyright 2000. Permission granted by Rodale, Emmaus, PA 18098. Available wherever books are sold or directly from the publisher by calling (800)848-4735 or visit Rodale's website at www.rodalestore.com.