The Science of Overeating

Dr. David Kessler, former head of the Food and Drug Administration, used to be a chronic overeater. He could not resist his favorite foods, nor could he regulate the amount of food that he ate. But not anymore.

Kessler has discovered that the reason most people overeat is because of a state he calls "conditioned hypereating," and he has the science to prove it.

Kessler and his colleagues conducted research into the mechanisms of overeating. These results will be published next week in his book, "The End of Overeating."

All of their research, says Kessler, indicates that overeating may be caused by the fat, sugar, and salt content in foods. In a process that resembles an addiction, these ingredients "condition" you to eat more of them, and to eat them more often.

The Proof is in the Pudding

Many studies have shown that foods high in both fat and sugar stimulate the brain's dopamine center. This is the same area-the brain's pleasure center-that drugs and alcohol stimulate to cause people to become addicted to them.

But, according to Kessler's study, sugar may be the major cause of "conditioned hypereating."

This study showed that rats, even ones that were not hungry, would work harder to get a drink of a vanilla milkshake if it contains a specific ratio of fat to sugar. But when researchers added even more sugar to the mix, the rats drank more of the milkshake.

Kessler and his team then analyzed the behaviors of "conditioned hypereaters," those who characterized themselves as having no control over their eating habits, were always hungry, and frequently thought about food. Of the people with those behaviors, Kessler said, 42 percent were obese. Conversely, only 18 percent of the people who did not exhibit these behaviors were obese.

Kessler and his colleagues then considered the results of a study conducted by Dana Small, a neuroscientist at Yale University. Small put hypereaters inside an MRI machine, then allowed them to smell and taste a chocolate milkshake. The brain scans showed that the longer the hypereaters were exposed to the smell of the chocolate milkshake, the more desirable the smell became to them. This is not normal, as constant exposure to a scent should dull the desire for it. Further, even being allowed to drink the milkshake did not assuage their cravings for it.

But hypereaters are not at the mercy of their dopamine conditioning, Kessler stresses; indeed, many conditioned hypereaters are thin. All you need to do is reprogram your mind.

Change the Conditioning

Kessler offers the following advice for those seeking to reverse their conditioned hypereating:

*Instead of thinking how delicious a certain food will be, tell yourself how much you will hate yourself if you eat it. Then replace your desire for that particular food, or foods, with an enjoyable alternative, either a lower calorie food or a physical activity.

*Before going to a place where you know they'll be fattening food, tell yourself that you will not be tempted by it.

*Avoid those "habitual-eating" situations of the past.

Kessler took his own advice, and now chronic hypereating is not much of a problem for him. He hopes that his book will encourage others to follow his lead.

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