WEIGHT LOSS: PHYSICAL ASPECTS OF ANOREXIA NERVOSA AND BULIMIA NERVOSA
Physical aspects of anorexia nervosa
Some of my anorexia patients tell me that they rarely feel hungry. They are so good at starving themselves, they say, because they’ve trained themselves to suppress hunger.
I’ve dealt with enough patients to know that’s not always the case. These people may be frequently hungry. Their illness is such that they must stand guard at all times lest hunger overwhelm them and they give in to the urge to eat even a mouthful of food.
Their claim that they don’t experience hunger may be in part a product of selective inattention. They don’t want to be hungry; therefore, eventually, they fool themselves into believing that they aren’t. They convert a hunger pang into a signal that they must work harder at being thin, through exercise or some other means. In part, however, their starvation may biologically decrease their perception of hunger.
Hunger denial isn’t present in all anorexics, though.
A patient named Jackie often remarked that yes, she did indeed feel hungry-a feeling she began to display as a kind of badge of valor. I once heard her remark to a fellow patient, “I could eat a horse- but of course I won’t.” Later, during a therapy session, I probed a little deeper into what she meant. Jackie replied, “If I can keep from eating even though my appetite is so huge, I know I’m succeeding in my quest to be thin. That success makes me feel very proud.”
Jackie thus revealed that she believed her extreme hunger (and her ability to resist it) marked her as a skilled soldier in the fight against fat. She actually cultivated her hunger because being aware of it helped make her feel thinner.
Some anorexic patients report that their efforts to starve themselves spring from their fear that they will eat beyond the point of fullness. For these individuals, a full stomach becomes a source of horror. If they eat enough to feel even a little full, they panic. They fear they have gone over the edge, that they have lost all control.
I treated a sixteen-year-old patient named Zoe, who had been anorexic for three years. Long after she began to improve, Zoe was still terrified that she might eat too much. Over the course of her illness, she said, “I think I’ve lost the ability to know how much food is enough.” Zoe’s satiety feedback loop had malfunctioned. It took months of treatment for this patient to relearn correct eating behavior.
Laboratory studies on anorexia patients often reveal that the hypothalamus isn’t functioning the way it should. Less clear is whether a defect in the hypothalamus causes the anorexia, or whether the effects of starvation have in turn affected the hypothalamus. Without going into detail, suffice it to say that, to different degrees in different patients, starvation and loss of body weight disrupt endocrine functions ranging from the thyroid to the liver to the reproductive organs.
These endocrine changes in anorexia occur along several body networks. Amenorrhea, loss of interest in sex, and reduction in breast size are all symptoms related to the pathway connecting the hypothalamus and the pituitary gland with the reproductive organs.
Other pathways link the hypothalamus to the nerves regulating blood pressure and heart rate, or to the body engines that turn our sleep cycles on and off.
There may even be a physiological network that governs one’s ability to perceive the body accurately. If so, disturbance of body image, one of the key symptoms of anorexia, may result from abnormalities in the neurotransmitter system.
At some point, the anorexic’s illusion that hunger doesn’t exist becomes a reality. In the terminal stages of the illness, hunger does indeed disappear. Without sufficient food, the body withers. The stomach shrinks, as does the small intestine. The ability of these organs to function shrinks as well. The stomach pumps out less digestive acid, and is thus less able to break down what little food is available. Eventually the stomach muscles may atrophy and lose their ability to pass food into the small intestine, a medically serious condition known as gastric dilatation.
Physical aspects of bulimia nervosa
Laboratory tests on bulimics reveal various endocrine abnormalities. Most of these, however, reflect the impact of bulimic behavior-bingeing and vomiting-on the body. They are the effects of the disorder, not the cause.
As we know, the act of vomiting depletes the body of essential fluids and chemicals. The passage of stomach acid up through the esophagus and out the mouth can burn or deteriorate the lining of the throat and causes tooth erosion. Loss of certain minerals threatens the ability of muscles to function properly. The heart is at high risk of developing an irregular rhythm or of stopping altogether. Affected by fluid imbalance, perhaps made worse by the use of diuretics, the kidneys malfunction. Menstruation becomes irregular, or stops altogether, due to changes in the body’s ability to manufacture and secrete hormones. The list-a sad one-goes on.
*45/35/5*
