By MARIAN BURROS


RIGHT in the middle of the season for fattening ourselves for the long, hard winter ahead, as if we were wolves or bears, an obesity specialist in Washington says we can make it easier to stop pigging out or we can make it harder. Naturally, many of us make it harder.

Unlike those who are always exhorting dieters to use willpower, Dr. C. Wayne Callaway, an endocrinologist and weight specialist at George Washington University, says that it is not really a matter of willpower. Or at least not willpower alone.

"Sure it's nice to have willpower and eat less and exercise more," Dr. Callaway said, but many people undermine their good intentions by failing to understand their bodies.

It seems logical that if you are expecting to eat a lot at a party at night, you ought to cut back on breakfast and lunch. You could starve all day and splurge on drinks and desserts, right? Wrong.

"The optimal thing is to have a regular breakfast and lunch," Dr. Callaway said, "so that when you sit down and eat you are not fighting genetically ingrained signals that cause your brain to get hungry after a meal."

Because of chemical changes that take place in the body after the first meal of the day, if you skip breakfast or skimp on it you will end up compensating later, he said. "Any time you undereat, you will eat the ordinary amount at the next meal, but shortly thereafter you will have the urge to keep on eating," Dr. Callaway said.

Humans, like animals, have a mechanism to help them compensate when food is in short supply. Our distant ancestors probably did not have a proper breakfast when they woke up in their caves, so they gorged whenever they made a kill. Even though there aren't many of us scratching out a living in the forest anymore, our brains are still wired for that potentially life-saving response to undereating.

Dr. Callaway explained: "In our world, when we try to skip or undereat, we are actually setting ourselves up for brain activity that produces an urge to eat that isn't satisfied by eating. It is not associated with an empty stomach. So the best thing to do is have regular meals and then you can enjoy the dessert without having three pieces."

Dr. Callaway added, "It's a lot easier to use willpower when you don't have that compensatory mechanism kicking in." Basically, our brains know how to prevent us from starving but not from getting fat. Wouldn't you know.

For the person who isn't overweight, overeating at holiday parties doesn't matter much. But for those who have a tendency to gain weight, it can send them down the road to ruin.

Temptations abound this month. Sweets and savories are often part of the holidays, even at the office, turning dedicated workers into grazers. "People who graze do not get the clear signals that they get at the end of a meal," Dr. Callaway said. So grazing often means eating more.

Another frequent trouble spot at holiday parties, increased consumption of alcohol, also contributes to weight gain in three different ways.

Alcohol, of course, adds calories. It also makes it even more difficult to exercise willpower. And when the liver is working to metabolize more than a moderate amount of alcohol — defined as two glasses of wine or beer for a man and one for a woman — its ability to make sugar is reduced. It makes fat instead.

"If you have several drinks a night for six weeks," Dr. Callaway said, "you will increase your interabdominal fat because the liver is making fat instead of burning it." Nice thought.

So if you don't want to store fat this season, Dr. Callaway recommends eating an adequate breakfast and lunch, limiting the alcohol and having a bowl of healthful soup before the rest of the meal.

Because, he said, Auguste Escoffier was right. "Soup calms down the violence of hunger."

You could start with my mother's mushroom barley soup.

The taste of this soup begins with the stock; the better it tastes, the better everything else will taste. High-quality beef stock is available at many specialty markets, rich and full bodied without being salted to a fare-thee-well.

It's not traditional, but adding wine vinegar to the soup gives it a sparkle.

http://www.nytimes.com/2002/12/18/d....html?tntemail0