The disciplines of nutrition and behavior are not usually
considered to be closely related, but there are infact several key
areas of overlap between these fields. Behavior factors determine the
choice of foods in the diet, and any attempt to change dietary patterns
must necessarily involve the central nervous system and may be
associated with mood changes.
That diet influences behavior is an ancient human belief. Primitive
people attributed friendly and unfriendly feelings to plants and
animals and expected these feelings to be transferred to anyone who ate
such foods. In religious teachings, the behavior of mankind was said to
change instantly when Eve ate the apple. Solomon, suffering the pangs
of love, was confronted with apples. The ancient Greeks proposed that
the body is composed of four "humors" - hot, cold, wet, and dry - that
control health, feelings, and behavior. Such ideas have carried forth
to the present day, when many cultures believe in hot/cold or yin/yang
approaches to food and health.
Systematic study of cultural influences on food intake began early
in this century as anthropologists examined the use of food in isolated
cultures and ethnic groups. Even in contemporary times, foods are
endowed with magical powers and are believed to symbolize feelings such
as those of satisfaction and security.
The reduction of behavioral risk factors for chronic disease, an
improvement of the food choices and dietary practices of individuals,
and the development of effective means to do so is the key to diet and
good health.
Behavioral determinants and aspects of eating disorders
Although infants do not begin life with a choice of foods, some of
the most obvious reflexes at birth are those associated with eating.
Infants learn to associate eating with security and relief from
anxiety, tension, and distress. Later, children eat in conformance to
cultural and familial standards. These ingrained meanings attached to
the roles of food in society suggest reasons that food habits can be
changed only with difficulty.
Although the choice of certain foods as opposed to others may
greatly affect nutritional status, food selection includes multiple
environmental, cultural, genetic, social, and sensory variables that
interact in complex ways. One exception appears to be an innate
preference for foods that are sweet. This preference is acquired in
early childhood and continues throughout life.
Selection of foods for nutritional or health reasons is a learned
behavior. Infants have not been shown to have an inborn ability to
select a balanced, nutritious diet. Variety of foods available has an
important effect on food consumption; the more the available foods are
varied, the more of them people will eat.
Behavior change is a key element in reducing the risk for chronic
disease. Eating behaviors are acquired over a lifetime, to change them
requires alterations in habits that must be continued permanently -
beyond any short-term period of intervention.
Dietary advice is often restrictive and viewed as depriving or
unpleasant. It may also be incompatible with cultural or familial
standards. Furthermore, environmental factors such as peer pressure,
advertising of high-calorie foods and alcoholic beverages may strongly
counteract recommended changes.
Despite these difficulties, considerable evidence supports the
effectiveness of nutrition education in changing dietary intake to
reduce risk factors for conditions such as coronary heart disease,
diabetes, hypertension, and neurologic disorders.
Obesity
Obesity is the excessive accumulation of fat in the body. The cause of obesity is quite simple - fat accumulates when more calories are consumed than are expended.
Obesity is often a familial disorder, obese parents tend to produce
obese offspring. Obesity is more common among women than among men, and
its prevalence increases with age but decreases among individuals of
higher socioeconomic status and greater levels of physical activity.
Once obesity is established, food choices and caloric intake are no
longer normal, and personality differences between obese and
normal-weight individuals may be due to results of physiologic changes,
social discrimination, or dieting.
Disparagement of body image affects a larger percentage of obese
persons than nonobese persons who characteristically dislike their own
bodies. Such feelings are closely associated with self-consciousness
and impaired social functioning.
Although weight reduction ought to confer great benefits upon obese
persons and be simple to accomplish, clinical experience has shown
obesity to be remarkably resistant to treatment. The basis of weight
reduction is deceptively simple: Establish an energy deficit by
consuming fewer calories than are expended or expending more calories
than are consumed. Most such treatment is carried out under the
direction of nonmedical groups and counsellors in programs that pose
some hazard and are of uncertain long-term effectiveness.
Treatment measures should be specified and outcomes evaluated;
treatment should be individualized; and treatment effectiveness should
be assessed. Behavioral weight control programs usually include group
participation at weekly meetings for periods of two months or more, and
involve techniques of stimulus control, eating behavior, reward,
self-monitoring, nutrition education and physical activity.
Obese patients who participate in regular peer group meetings
following the completion of formal treatment maintain their weight loss
better than those who do not participate in such meetings.
It is important to make a note about obesity and the numerous
"weight loss formulas" that are currently marketed. These products
range from diet pills to drinks that supposedly will make weight loss
happen without any other dietary changes.
There is not a single, safe formula available that will cause
permanent weight loss without any adverse effects on the health of the
user. The proof of this is the fact that irrespective of the amount of
products that come and go, obesity still exists among about one third
of the population - millions of people. If there was one product that
was successful, obesity would no longer be a problem and the "inventor"
of this product would probably be the richest person in the world.
Do not take any "formula" for weight loss, you are wasting your
time, money, and probably health by doing so. Rather, follow the
dietary guidelines found in this book to achieve a desirable weight and
healthy lifestyle.
Anorexia Nervosa
Anorexia nervosa is a condition characterized by extreme weight
loss, amenorrhoea, and a constellation of psychologic problems that
have been described as "the relentless pursuit of thinness". [Bruch, H., Eating disorders: obesity, anorexia nervosa and the person within. New York. 1979.]
The most common cause of the disease is a single episode with full
recovery, but anorexia nervosa can be episodic or unremitting until it
causes death by starvation.
Unlike many other psychiatric disorders, anorexia nervosa tends to
occur in intact families and is often precipitated by seemingly minor
events during adolescence. Most theories of anorexia nervosa focus on
psychologic trauma or unempathetic and overly domineering mothering as
underlying causes of the disease. Socio-cultural theories suggest that
the disease represents an exaggeration of the current inordinate weight
consciousness of adolescent girls at a time when high-calorie foods are
readily available and fewer calories are expended through exercise.
Typical symptoms of the disease include depression and
obsessive-compulsive behaviors, it is not clear if these psychiatric
problems preceded weight loss or occur as a result of semistarvation.
Depression is often the first visible sign of anorexia nervosa.
Abnormal hormonal patterns characteristic of starvation also occur.
The clinical features of anorexia nervosa are personality
characteristics such as rigidity or perfectionism, fear of obesity
preceding the onset of the disorder, and the symptoms of starvation
accompanying it. Serious body image disturbance is common, manifested
by a lack of recognition of the severe emaciation and a belief that one
is too fat. Individuals are often preoccupied with food, thinking about
it much of the time, and often engaging in bizarre eating rituals. Many
anorectics engage in very extensive physical exercise. The disorder is
also associated with a pervasive sense of personal ineffectiveness.
Anorectics are divided into two types, "restricters" who confine
their eating disorder to restricted food intake, and "bulimics" who
engage in bingeing and subsequent vomiting and purging. Bulimic
anorectics tend to be older, manifest other impulsive behaviors such as
kleptomania, alcohol and drug abuse, and sexual promiscuity.
Anoretics deny their weight-losing behaviors and the existence of
any illness and avoid treatment even when they have become severely
emaciated. Family members often have to insist on medical treatment.
Some anoretic persons effectively hide their weight-losing behaviors
even after they are forced to seek medical assistance.
Most persons with anorexia are resistant to entering treatment
because of their fear of weight gain and are usually brought, by family
members, under protest. Because starvation plays a significant role in
the clinical portrayal of anorexia nervosa, clinicians begin treatment
with a period in hospital designed to restore body weight. Such
treatment that removes the patient from the environment may permit the
use of behavioral rewards for weight gain and provides the opportunity
to work on issues of control. Some medications have been helpful in the
treatment of anorexia nervosa. These include cyproheptadine (an
appetite stimulant), chlorpromazine (sedative, used in the treatment of
psychotic conditions), and antidepressant medication.
Bulimia
Bulimia is an eating disorder characterized by recurrent episodes of
binge eating in which large amounts of food are consumed over a short
period of time. These episodes are usually terminated by abdominal
pain, self-induced vomiting, sleep, or the appearance of another person
on the scene.
Bulimia occurs among persons of normal weight but is present in half
the patients with anorexia nervosa. The severity of binge eating ranges
from occasional episodes of morbid overeating at a party to the severe
form of the disorder, bulimia nervosa, in which the vomiting or purging
follows frequent episodes of binge eating.
There are many similarities between persons with anorexia nervosa
and bulimia. Both occur primarily in young women, although bulimia
occurs in slightly older individuals, both may relate to the current
preoccupation with thinness and dieting.
The symptoms of depression in the majority of bulimic patients and
the presence of biologic markers of depression suggest that bulimia may
represent a variant of mood disorder. Treatment of bulimia is
cognitive-behavioral and pharmacologic. Behavioral treatment include
modification of the behavioral program designed for obese patients and
a combination of cognitive-behavioral and insight-oriented approaches.
Pica
Pica is the intentional and compulsive consumption of non-food
substances. It occurs worldwide and is common among people of either
sex and of all ages and races. Pica is often associated with
nutritional deficiencies or toxicities, and is of special concern among
young children and pregnant women.
Geophagia is the consumption of earth and clay. Amylophagia is the
consumption of starch and paste, and pagophagia is the eating of ice.
The fourth category includes the consumption of ash, chalk, antacids,
paint chips, plaster, wax, and other substances.
People appear to be driven to consume these substances by
nutritional deficiencies, but pica is not necessarily correlated with
poor nutritional status. The nutritional hazards most frequently
associated with pica are lead poisoning and iron deficiency anaemia.
Hypoglycaemia
Hypoglycaemia (low blood
sugar) can occur either after a fast (fasting hypoglycaemia) or several
hours after the consumption of a meal (reactive hypoglycaemia). Many
individuals have symptoms of weakness, confusion, and irritability
after eating sugars or other carbohydrate foods.
True reactive hypoglycaemia is diagnosed when symptoms of sweating,
tremor, anxiety, and irritability occur at the same time as the
documented low blood sugar level. Such a diagnosis may indicate the
early presence of a disease such as diabetes.
Hyperactive behavior
Hyperactivity is a childhood problem often discussed in relation to
nutrition. This condition is characterized by problems of inattention,
excessive motion, impulsivity, learning disabilities, and related
problems of conduct.
Food additives, especially artificial dyes and colours, can cause hyperactivity.
Implications for Public Health Policy
Studies in patients with eating disorders and other chronic disease
conditions emphasize the importance of modification of diet-related
behavior in these conditions. Although evidence linking dietary
caffeine, refined sugars, and food additives to behavioral disorders is
uncertain, their elimination from thediet will not impair nutritional
status and can be recommended to patients on an individual trial basis.
Nutrition Programs and Services
Food Labels:Evidence related to the role of dietary factors in behavioral disorders holds no implication for food labeling policies.
Food Services:Evidence related to the role of dietary
factors in behavioral disorders holds no special implications for
changes in policies related to food programs beyond the dietary
guidelines suggested by Department of Agriculture and the Department of
Health and Human Services. [The Surgeon General's Report on Nutrition & Health, 1988.]
