[ Log On ]

Eating behaviors and moods

Many overweight people have recognized the tendency to eat more and gain weight when they are under stress or pressure. They identify this increased eating as a response to feelings of anxiety and depression, sadness or loss, and as a way of attempting to comfort themselves that is familiar and acceptable. What most people don't understand is that the areas of the brain that regulate our emotional responses - the degree of anxiety and agitation, sadness and depression - are interconnected with the parts of the brain that regulate eating and satiety (fullness), and are under the influence of a common set of neurotransmitters and neuromodulators (chemicals which regulate function within the brain).

The urge to eat in response to emotional distress is not only a psychological pattern or habit ingrained in childhood, but may represent a physiological response to changes in fundamental brain chemistry. For this reason, treatment of the underlying anxiety and depression can often remove the urge to overeat and provide the motivation and confidence necessary to succeed in a dietary program. This is especially true with compulsive overeating or binge eating disorder.

Many people who have suffered with depression off and on throughout their lives assume that it is simply a part of their existence - something to be tolerated like one's height or eye color. In reality, however, people who tire easily, have trouble getting started, feel tired and weak, want to oversleep, or have trouble sleeping,often suffer from a medical disorder, much like high blood pressure or diabetes. Medications that are helpful in reversing these symptoms of depression can also help prevent recurrences.

Many people wonder how a pill could help with sadness or anxiety or if it is only a crutch. They are confusing the ordinary and universal human conditions, such as frustration, disappointment, adversity, job dissatisfaction, and failure in relationships with depression, an excessive physiological response to stress.

Depression in the medical sense means that certain vital functions, including eating, sleeping, energy, concentration, and activity, have been altered. When people show changes in many of these areas at the same time, they are reflecting a fundamental shift in the brain chemistry that regulates daily vital functions. This over-response to stress may eventually resolve on its own, but this process can take months or even years, leaving the person's life devastated and disrupted.

Clinical studies of outpatients with depression show that weight gain is one of the most common symptoms. Appropriate treatment with newer antidepressants significantly reduces the urge to overeat, restores normal appetite function, and improves the motivation and commitment to follow through on a dietary program. This is especially important in the acute phase of weight loss, when so many people who have had weight problems are vulnerable to failure and defeat their intense efforts.

Part of a comprehensive evaluation of obese individuals is to determine whether they are experiencing depression and could benefit from appropriate medications. Comprehensive physical examinations, laboratory tests, and sometimes endocrine tests, can be extremely helpful in identifying the patients who can benefit from antidepressant therapy.

Binge eating and purging (bulimia nervosa)

It seems as though most people in our (Western) culture feel that a person can never be too thin. Because the problems of obesity and the tendency to become overweight are much greater in women than in men, the pressure to be thin and stay thin is far greater on young women.

Starting in the 1980's, the response to the cultural pressure to maintain this body ideal was an epidemic of a condition now called bulimia nervosa. In bulimia nervosa, (mostly) young women frequently binge eat, purge, or fast for long periods of time as a way of controlling their weight. There is an intense fear of becoming obese, so much so that the person feels an urge to purge themselves in order to avoid the possibility of gaining weight. This may be associated with an intense feeling of fullness even after a small meal.

Women with bulimia nervosa often binge up to ten or even twenty times per day. They frequently eat large quantities of carbohydrates in a single sitting and then purge themselves to eliminate the food from their bodies. As their concerns about their weight escalate, they may also turn to laxatives, diuretics, and pills as ways of maintaining their weight. Once in place, this pattern of binge eating and purging can continue over a lifetime.

While the psychological basis of bulimia nervosa is debatable, research has shown a link between bulimia and severe depression and anxiety. A significant proportion of patients with bulimia nervosa have relatives who suffer from severe depression and/or mood swings. Approximately half of all bulimic patients become clinically depressed at some point in their course of illness, an incidence three to five times greater than in the general population.

Clinical studies have looked at the possible benefits of antidepressant medications for bulimics and have found a dramatic decline in the frequency of binge-and-purge episodes in response to antidepressants, regardless of whether the bulimic patient was suffering from depression at the time.

Researchers believe that the same chemicals that affect mood also regulate eating and satiety; thereby accounting for the effect of certain antidepressants in reducing bulimic behavior. Therefore, whether a person experiences hunger or fullness is a function not only of habit and behavior modeling, but also of specific concentrations of the neurotransmitters serotonin and norepinephrine in various nuclei (centers) in the hypothalamus, a part of the brain that regulates vital functions.

Bulimia nervosa is a potentially serious condition that disrupts the body's chemistries, causes harm to the digestive tract, erodes tooth enamel, and creates the risk of potentially fatal heart irregularities due to impaired physical health or chemical imbalances.

Most patients with bulimia nervosa can be treated in outpatient settings with a combination of psychotherapy and medications, enabling them to continue work or school. The shame and embarrassment so many bulimics share can be put aside while they learn new behaviors and coping mechanisms. In this atmosphere, the urge to binge and purge is reduced by appropriate medical and psychiatric management.

Anorexia nervosa

Anorexia nervosa is the formal name given to a condition in which patients, mostly women, seek to continually lower their body weights. They believe they look better as they become more and more depleted and wasted. Anorexics have a distorted body image. They think they are too fat, no matter what their weight is, and always want to become thinner. Anorexia nervosa is the most medically serious and least understood of all the eating disorders. Patients with anorexia nervosa often develop secondary changes in their endocrine system, such as the absence of menstrual periods.

Psychologists studying this condition have speculated that patients with anorexia nervosa want to return to a pre-pubertal state as a way of dealing with intense anxiety related to sexual development. Biological investigators have focused on abnormalities in the endocrine system, such as excessive cortisol production, abnormal regulation of water balance, abnormal thyroid function, elevated resting metabolic rate, and exaggerated responses to leptin, a hormonal product primarily secreted by fat cells, as indications of the biological disturbance this condition causes.

Individuals with anorexia nervosa attempt to control their body weights through a number of different strategies, such as compulsive hyperactivity. For example, one patient would jog five hours per day, then come home, wash, and go on an exercycle for another hour. Her day was spent trying to burn off any and all calories that she consumed.

Others will restrict food. They eat as few calories as possible and, as a result, are able to continuously drive their weight down. Anorexics, like bulimics, can become progressively desperate if they see their weight increasing. At those times, they are likely to start inducing vomiting (purging) or abusing laxatives, diuretics, or appetite suppressants. Intense depression, anxiety, and insomnia are common in patients with anorexia nervosa.

Because anorexia nervosa involves a significant degree of self-starvation, affected individuals deprive their bodies of essential nutrients that are necessary for maintaining normal brain function, which actually results in at least temporary shrinkage of the brain itself. The psychological symptoms of anorexia nervosa rarely diminish until an anorexic regains sufficient weight to maintain normal endocrine and neurochemical functions. Therefore, the treatment of anorexia nervosa is primarily focused on controlling the behaviors anorexics use to drive their weight down and establishing clear weight goals.

Although the majority of patients with mild anorexia nervosa can be managed on an outpatient basis, frequently hospitalization is required if the individual's weight begins to fall dramatically or if their electrolytes (salts in the blood) become disturbed by purging and laxative abuse. Following an episode of acute anorexia nervosa, approximately two-thirds of patients recover completely and one-third have periodic problems during their lifetimes. Those who have abandoned hope of being helped can now find definitive treatment.

My sincere appreciation to David Sack, M.D. for his assistance and commentary.

Updated: 27 December 2011

All rights reserved.

Disclaimer Statement
