Nutrition: Why Fat People Keep Eating

Stomach contractions are generally unmistakable hunger signals to the stomach's owner. They are, that is, if the owner is a healthy man or woman in the normal weight range. Nature's built-in control mechanisms, reinforced by habit, are so strong that most people feel hungry three or four times a day, and when they do, they automatically eat the necessary amount of food. The trouble with most overweight men and women, say two Philadelphia researchers, is that their signaling system has somehow broken down. They feel hunger pangs, but they fail to get the message to take in food. As a paradoxical result, they eat more, and they eat more often.

University of Pennsylvania Psychiatrists Dr. Albert Stunkard and Dr. Charles Koch made their experiments on test subjects who were grossly overweight. The women averaged 62% heavier than normal for their height and bone build, and one weighed almost three times what she should have. The men averaged 44% overweight, including one 600-pounder—a fourfold fatty. After a night without food and no breakfast, the volunteers swallowed a stomach tube with balloon attached. Every 15 minutes the doctors asked: "Are you hungry? Does your stomach feel empty? Do you want to eat?" Normal subjects, tested for comparison, felt hungry whenever the pressure in the balloon showed they were having stomach contractions. Not the obese patients. Overweight women rarely admitted that they felt hungry, even when their stomachs said they should, the doctors report in the Archives of General Psychiatry. Overweight men said they felt hungry nearly all the time, even when their stomach pressure said they shouldn't.

The reason the obese subjects did not respond normally and automatically to the stomach's signals, say the psychiatrists, could probably be traced to deep emotional problems. Eating had become, for them, "a matter of conscious and desperate choice at meal after meal." Many admitted that it had been years since they could trust their senses as to how much to eat. So they ate heavily and did not know when to stop. All of which points up a new problem: how to retrain these fat people to eat on signal—and only on signal.