How Nutrition Can Effect Our Behavior

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.]

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