Diets

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Definition

Special diets are designed to help individuals make changes in their usual eating habits or food selection. Some special diets involve changes in the overall diet, such as diets for people needing to gain or lose weight or eat more healthfully. Other special diets are designed to help a person limit or avoid certain foods or dietary components that could interfere with the activity of a medication. Still other special diets are designed to counter nutritional effects of certain medications.

Purpose

Special diets are used in the treatment of persons with certain mental disorders to:

identify and correct disordered eating patterns
prevent or correct nutritional deficiencies or excesses
prevent interactions between foods or nutrients and medications

Special types of diets or changes in eating habits have been suggested for persons with certain mental disorders. In some disorders, such as eating disorders or substance abuse, dietary changes are an integral part of therapy. In other disorders, such as attention-deficit/hyperactivity disorder , various proposed diets have questionable therapeutic value.

Many medications for mental disorders can affect a person's appetite or nutrition-related functions such as saliva production, ability to swallow, bowel function, and activity level. Changes in diet or food choices may be required to help prevent negative effects of medications.

Finally, interactions can occur between some medications used to treat persons with mental disorders and certain foods or nutritional components of the diet. For example, grapefruit and apple juice can interact with some specific psychotropic drugs (medications taken for psychiatric conditions) and should be avoided by individuals taking those medicines. Tyramine, a natural substance found in aged or fermented foods, can interfere with the functioning of monoamine oxidase inhibitors and must be restricted in individuals using these types of medications. A person's pre-existing medical condition and nutritional needs should be taken into account when designing any special diet.

Special diets for specific disorders

Eating disorders

The two main types of eating disorders are anorexia nervosa and bulimia nervosa . Individuals with anorexia nervosa starve themselves, while individuals with bulimia nervosa usually have a normal or slightly above normal body weight but engage in binge eating followed by purging with laxatives, vomiting, or exercise.

Special diets for individuals with eating disorders focus on restoration of a normal body weight and control of bingeing and purging. These diets are usually carried out under the supervision of a multidisciplinary team, including a physician, psychologist , and dietitian.

The overall dietary goal for individuals with anorexia nervosa is to restore a healthy body weight. An initial goal might be to stop weight loss and improve food choices. Energy intake is then increased gradually until normal weight is restored. Because individuals with anorexia nervosa have an intense fear of gaining weight and becoming fat, quantities of foods eaten are increased very slowly so that the patient will continue treatments and therapy.

The overall dietary goal for individuals with bulimia nervosa is to gain control over eating behavior and to achieve a healthy body weight. An initial goal is to stabilize weight and eating patterns to help the individual gain control over the binge-purge cycle. Meals and snacks are eaten at regular intervals to lessen the possibility that hunger and fasting will trigger a binge. Once eating behaviors have been stabilized, energy intake can be gradually adjusted to allow the individual to reach a normal body weight healthfully.

For individuals with either anorexia nervosa and bulimia, continued follow-up and support are required even after normal weight and eating behaviors are restored, particularly since the rate of relapse is quite high. (Relapse occurs when a patient returns to the old behaviors that he or she was trying to change or eliminate.) In addition to dietary changes, psychotherapy is an essential part of the treatment of eating disorders and helps the individual deal with fears and misconceptions about body weight and eating behavior.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) accounts for a substantial portion of referrals to child mental health services. Children with ADHD are inappropriately active, easily frustrated or distracted, impulsive, and have difficulty sustaining concentration. Usual treatment of ADHD involves medication, behavioral management, and education.

Many dietary factors have been proposed as causes of ADHD, including sugar, food additives, and food allergies. In the 1970s the Feingold diet became popular for treatment of ADHD. The Feingold diet excludes artificial colorings and flavorings, natural sources of chemicals called salicylates (found in fruits), and preservatives called BHT and BHA. Although scientific evidence does not support the effectiveness of the Feingold diet, a modified Feingold diet including fruits has been shown to be nutritionally balanced and should not be harmful as long as the child continues to receive conventional ADHD treatment also.

A high intake of sugar and sugary foods has also been implicated as a cause of ADHD. Although carefully controlled studies have shown no association between sugar and ADHD, diets high in sugar should be discouraged because they are often low in other nutrients and can contribute to dental problems.

Food allergies have also been implicated as a cause of ADHD, and some groups have suggested using elimination diets to treat ADHD. Elimination diets omit foods that most commonly cause allergies in children, such as eggs, milk, peanuts, or shellfish. Although research does not support the value of elimination diets for all children with ADHD, children with specific food allergies can become irritable and restless. A child with a suspected food allergy should be evaluated by an allergist.

Stimulant medications used to treat ADHD, such as methylphenidate (Ritalin), can cause appetite loss (anorexia) and retard growth, although recent research suggests that a child's ultimate height appears not to be affected by stimulant medications. As a precaution, children on such medicines should receive close monitoring of growth patterns, and parents should carefully observe their child's appetite and interest in meals and snacks. Providing regular meals and snacks, even when the child is not hungry, can help to assure adequate growth.

Mood disorders

Mood disorders include both depression (unipolar disorder) and episodes of mania followed by depression ( bipolar disorder ). Both types of disorders can affect appetite and eating behavior.

Although some depressed individuals eat more than usual and gain weight, depression more often causes loss of appetite and weight loss. As depressed individuals lose interest in eating and social relationships, they often skip meals and ignore feelings of hunger. Unintentional weight losses of up to 15% of body mass can occur.

Treatment with antidepressant medications often reverses weight loss and restores appetite and interest in eating. If the individual has lost a significant amount of weight, he or she may need to follow a high-calorie diet to restore weight to normal levels and replaced nutritional deficiencies. High-calorie diets usually include three balanced meals from all the food groups and several smaller snacks throughout the day. A protein/calorie supplement may also be necessary for some individuals.

Depression is sometimes treated with medications called monoamine oxidase inhibitors. Individuals on these medications will need to follow a tyramine-restricted diet (see below under monoamine oxidase inhibitors).

Individuals with mania are often treated with lithium. Sodium and caffeine intake can affect lithium levels in the blood, and intake of these should not suddenly be increased or decreased. Weight gain can occur in response to some antidepressant medications and lithium.

Schizophrenia

Individuals with schizophrenia can have hallucinations , delusional thinking, and bizarre behavior. These distorted behaviors and thought processes can also be extended to delusions and hallucinations about food and diet, making people with schizophrenia at risk for poor nutrition.

Individuals with schizophrenia may believe that certain foods are poisonous or have special properties. They may think they hear voices telling them not to eat. Some may eat huge quantities of food thinking that it gives them special powers. Individuals with untreated schizophrenia may lose a significant amount of weight. Delusional beliefs and thinking about food and eating usually improve once the individual is started on medication to treat schizophrenia.

Substance abuse

Substance abuse can include abuse of alcohol, cigarettes, marijuana, cocaine, or other drugs. Individuals abusing any of these substances are at risk for nutritional problems. Many of these substances can reduce appetite, decrease absorption of nutrients into the body, and cause the individual to make poor food choices.

Special diets used for withdrawal from substance abuse are designed to correct any nutritional deficiencies that have developed, aid in the withdrawal of the substance, and prevent the individual from making unhealthful food substitutions as the addictive substance is withdrawn. For example, some individuals may compulsively overeat when they stop smoking, leading to weight gain. Others may substitute caffeine-containing beverages such as soda or coffee for an addictive drug. Such harmful substitutions should be discouraged, emphasizing well-balanced eating combined with adequate rest, stress management, and regular exercise. Small, frequent meals and snacks that are rich in vitamins and minerals from healthful foods should be provided. Fluid intake should be generous, but caffeine-containing beverages should be limited.

Individuals withdrawing from alcohol may need extra thiamin supplementation, either intravenously or through a multivitamin supplement because alcohol metabolism in the body requires extra thiamin. Individuals taking drugs to help them avoid alcohol will need to avoid foods with even small amounts of alcohol (see below).

Common withdrawal symptoms and dietary suggestions for coping with these symptoms include:

Appetite loss: eat small, frequent meals and snacks; limit caffeine; use nutritional supplements if necessary.
Appetite increase: eat regular meals; eat a variety of foods; limit sweets and caffeine.
Diarrhea: eat moderate amounts of fresh fruits, vegetables, concentrated sugars, juices, and milk; increase intake of cereal fiber.
Constipation: drink plenty of fluids; increase fiber in the diet; increase physical activity.
Fatigue: eat regular meals; limit sweets and caffeine; drink plenty of fluid.

Dietary considerations and medications

Medications that affect body weight

Many medications used to treat mental disorders promote weight gain, including:

anticonvulsants (divalproex)
certain types of antidepressants ( amitriptyline )
antipsychotic medications ( clozapine , olanzapine , quetiapine , and risperidone)

Dietary treatments for individuals taking these medications should focus on a balanced, low-fat diet coupled with an increase in physical activity to counter the side effects of these medications. Nutrient-rich foods such as fruits, vegetables, and whole grain products should be emphasized in the diet, whereas sweets, fats, and other foods high in energy but low in nutrients should be limited. Regular physical activity can help limit weight gain caused by these medications.

Some medications can cause loss of appetite, restlessness, and weight loss. Individuals on such medications should eat three balanced meals and several smaller snacks of protein and calorie-rich foods throughout the day. Eating on a regular schedule rather than depending on appetite can help prevent weight loss associated with loss of appetite.

Medications that affect gastrointestinal function

Many psychiatric medications can affect gastrointestinal functioning. Some drugs can cause dry mouth, difficulty swallowing, constipation, altered taste, heartburn, diarrhea, or nausea. Consuming frequent smaller meals, drinking adequate fluids, modifying texture of foods if necessary, and increasing fiber content of foods can help counter gastrointestinal effects of medications.

Monoamine oxidase inhibitors

Individuals being treated with monoamine oxidase inhibitors (MAOIs) such as tranylcypromine , phenelzine , and isocarboxazid, must carefully follow a tyramine-restricted diet. Tyramine, a nitrogen-containing substance normally present in certain foods, is usually broken down in the body by oxidases. However, in individuals taking MAOIs, tyramine is not adequately broken down and builds up in the blood, causing the blood vessels to constrict and increasing blood pressure.

Tyramine is normally found in many foods, especially protein-rich foods that have been aged or fermented, pickled, or bacterially contaminated. Cheese is especially high in tyramine. A tyramine intake of less than 5 milligrams daily is recommended. A diet that includes even just 6 milligrams of tyramine can increase blood pressure; a diet that provides 25 milligrams of tyramine can cause life-threatening increases in blood pressure.

TYRAMINE-RESTRICTED DIET. Tyramine is found in aged, fermented and spoiled food products. The tyramine content of a specific food can vary greatly depending on storage conditions, ripeness, or contamination. Reaction to tyramine-containing foods in individuals taking MAOIs can also vary greatly depending on what other foods are eaten with the tyramine-containing food, the length of time between MAOI dose and eating the food, and individual characteristics such as weight, age, etc.

Foods to avoid on a tyramine-controlled diet include:

all aged and mature cheeses or cheese spreads, including foods made with these cheeses, such as salad dressings, casseroles, or certain breads
any outdated or nonpasteurized dairy products
dry fermented sausages such as summer sausage, pepperoni, salami, or pastrami
smoked or pickled fish
non-fresh meat or poultry
leftover foods containing meat or poultry
tofu and soy products
overripe, spoiled, or fermented fruits or vegetables
sauerkraut
fava or broad beans
soups containing meat extracts or cheese
gravies containing meat extracts or nonfresh meats
tap beer
nonalcoholic beer
yeast extracts
soy sauce
liquid powdered protein supplements

Perishable refrigerated items such as milk, meat, or fruit should be eaten within 48 hours of purchase. Any spoiled food and food stored in questionable conditions should not be eaten.

Lithium

Lithium is often used to treat individuals with mania. Lithium can cause nausea, vomiting, anorexia, diarrhea, and weight gain. Almost one-half of individuals taking lithium gain weight.

Individuals taking lithium should maintain a fairly constant intake of sodium (found in table salt and other food additives) and caffeine in their diet. If an individual restricts sodium intake, less lithium is excreted in the urine and blood lithium levels rise. If an individual increases caffeine intake, more lithium is excreted in the urine and blood levels of lithium fall.

Anticonvulsant medications

Sodium caseinate and calcium caseinate can interfere with the action and effectiveness of some anticonvulsants. Individuals taking these anticonvulsants should read labels carefully to avoid foods containing these additives.

Psychotropic medications

Some psychotropic medications, such as amitriptyline, can decrease absorption of the vitamin riboflavin from food. Good food sources of riboflavin include milk and milk products, liver, red meat, poultry, fish, and whole grain, and enriched breads and cereals. Riboflavin supplements may also be needed.

Other psychotropic drugs, such as fluvoxamine , sertraline , fesasodone, alprazolam , triazolam , midazolam, carbamazepine , and clonazepam , interact with grapefruit juice, so individuals taking these drugs must take care to avoid grapefruit juice. In some cases, apple juice must be avoided, as well. Patients should discuss potential drug interactions with their doctor or pharmacist.

Caffeine-restricted diet

Caffeine is a stimulant and can interfere with the actions of certain medications. As stated, people taking lithium and people recovering from addictions may be asked by their treatment team to monitor (and, in the case of addictions, restrict) their caffeine intake. Foods and beverages high in caffeine include:

chocolate
cocoa mix and powder
chocolate ice cream, milk, and pudding
coffee
cola beverages
tea

Alcohol-restricted diet

Alcohol interacts with some medications used to treat mental disorders. In the case of alcoholism recovery, the negative interaction resulting from the combination of one medication ( disulfiram or Antabuse) and alcohol consumption is actually part of treatment for some people. (The medication causes an extremely unpleasant reaction to any alcohol consumed, reinforcing or rewarding the avoidance of alcohol.)

When individuals are taking medication that requires that they avoid alcohol, foods containing alcohol must be avoided as well as beverage alcohol. The following foods contain small amounts of alcohol:

flavor extracts, such as vanilla, almond, or rum flavorings
cooking wines
candies or cakes prepared or filled with liqueur
apple cider
cider and wine vinegar
commercial eggnog
bernaise or bordelaise sauces
desserts such as crepes suzette or cherries jubilee
teriyaki sauce
fondues

Resources

BOOKS

American Dietetic Association and Dietitians of Canada. Manual of Clinical Dietetics. 6th edition. Chicago, Illinois: American Dietetic Association, 2000.

Fairburn, C.G., D.M., M. Phil., F.R.C.Psych. "Eating disorders." In Human Nutrition and Dietetics, edited by J.S. Garrow, M.D., Ph.D., W.P.T. James, M.D., S.Sc., and A. Ralph, Ph.D. 10th edition. New York: Churchill Livingstone, 2000.

Huse, Diane M., M.S., R.D. and Alexander R. Lucas, M.D. "Behavioral Disorders Affecting Food Intake: Anorexia Nervosa, Bulimia Nervosa, and Other Psychiatric Conditions." In Modern Nutrition in Health and Disease, edited by Maurice E. Shils, M.D., Sc.D., James A. Olson, Ph.D., Moshe Shike, M.D., and A. Catharine Ross, Ph.D. 9th edition. Baltimore: Williams and Wilkins, 1999.

Queen, Patricia M., M.M.Sc., R.D. and Carol E. Lang, M.S., R.D. Handbook of Pediatric Nutrition. Gaithersburg, Maryland: Aspen Publishers, Inc., 1993.

ORGANIZATIONS

American Dietetic Association. 216 West Jackson Boulevard, Chicago, Illinois, 60606-6995. <http://www.eatright.org> .

OTHER

National Institutes of Health Consensus Development. "Defined diets and childhood hyperactivity." National Institutes of Health Consensus Development Conference Summary 4, no. 3 (1982).

Nancy Gustafson, M.S., R.D., F.A.D.A., E.L.S.