Diets

Definition

Purpose

Special diets for specific disorders

Dietary considerations and medications

Caffeine-restricted diet

Alcohol-restricted diet

Resources

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 people 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 people 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 people 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 (MAOIs) and must be restricted in individuals using these types of medications. A person’s preexisting 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, whereas individuals with bulimia nervosa usually have 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 normal body weight and control of bingeing and purging. These diets are usually carried out under the supervision of a multidiscipli-nary 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 individuals 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 individuals to reach normal body weights healthfully.

For individuals with either anorexia nervosa or 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. In addition to dietary changes, psychotherapy is an essential part of the treatment of eating disorders and helps individuals 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 Fein-gold 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. Children 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 individuals with depression eat more than usual and gain weight, depression more often causes loss of appetite and weight loss. As individuals with depression 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 individuals have lost a significant amount of weight, they 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 (MAOIs). Individuals on these medications will need to follow a tyramine-restricted diet.

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 individuals are 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 individuals 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.

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

• appetite loss: Eat small, frequent meals and snacks; limit caffeine; and use nutritional supplements if necessary.
• appetite increase: Eat regular meals; eat a variety of foods; and limit sweets and caffeine.
• diarrhea: Eat moderate amounts of fresh fruits, vegetables, concentrated sugars, juices, and milk; and increase intake of cereal fiber.
• constipation: Drink plenty of fluids; increase fiber in the diet; and increase physical activity.
• fatigue: Eat regular meals; limit sweets and caffeine; and 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 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 oxidase. 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 mg daily is recommended. A diet that includes even just 6 mg of tyramine can increase blood pressure; a diet that provides 25 mg 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
• nonfresh 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 drugs 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, 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 doctors or pharmacists.

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 when any alcohol is 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

KEY TERMS

Anorexia —Loss of appetite or unwillingness to eat. Can be caused by medications, depression, or many other factors.

Anorexia nervosa —An eating disorder characterized by an intense fear of weight gain accompanied by a distorted perception of one’s own underweight body.

Binge —An excessive amount of food consumed in a short period of time. Usually, while people binge eat, they feel disconnected from reality, and feel unable to stop. The bingeing may temporarily relieve depression or anxiety, but after the binge, they usually feel guilty and depressed.

Bulimia nervosa —An eating disorder characterized by binges in which large amounts of food are consumed, followed by forced vomiting.

Psychotropic drug —Medication that has an effect on the mind, brain, behavior, perceptions, or emotions. Psychotropic medications are used to treat mental illnesses because they affect a patient’s moods and perceptions.

Purge —When a person rids extra food consumed by inducing vomiting, laxative abuse, or excessive exercise.

Relapse —People experience relapses when they reengage in behaviors that are harmful and that they were trying to change or eliminate. Relapse is a common occurrence after treatment for many disorders, including addictions and eating disorders.

Thiamin —A B-vitamin that is essential to normal metabolism and nerve function, and whose absorption is affected by alcoholism.

Tyramine —An intermediate product between the chemicals tyrosine and epinephrine in the body and a substance normally found in many foods. It is found especially in protein-rich foods that have been aged or fermented, pickled, or bacterially contaminated, such as cheese, beer, yeast, wine, and chicken liver.

See alsoNutrition counseling; Nutrition and mental health.

Resources

BOOKS

Logue, Alexandra. The Psychology of Eating and Drinking. 3rd ed. New York: Routledge, 2004.

Bronner, Felix. Nutritional Aspects and Clinical Management of Chronic Disorders and Diseases. Boca Raton, FL: CRC, 2002.

PERIODICALS

Daubenmier, Jennifer J., and others. “The Contribution of Changes in Diet, Exercise, and Stress Management to Changes in Coronary Risk in Women and Men in the Multisite Cardiac Lifestyle Intervention Program.” Annals of Behavioral Medicine 33.1 (Feb. 2007): 57–68.

Groesz, Lisa M., and Eric Stice. “An Experimental Test of the Effects of Dieting on Bulimic Symptoms: The Impact of Eating Episode Frequency.” Behaviour Research and Therapy 45.1 (Jan. 2007): 49–62.

Hagler, Athena S., and others. “Psychosocial Correlates of Dietary Intake Among Overweight and Obese Men.” American Journal of Health Behavior 31.1 (Jan.-Feb. 2007): 3–12.

Jabs, Jennifer, and Carol M. Devine. “Time Scarcity and Food Choices: An Overview.” Appetite 47.2 (Sept. 2006): 196–204.

Leung, Newman, and Emma Price. “Core Beliefs in Dieters and Eating Disordered Women.” Eating Behaviors 8.1 (Jan. 2007): 65–72.

Mobbs, Charles V., and others. “Low-Carbohydrate Diets Cause Obesity, Low-Carbohydrate Diets Reverse Obesity: A Metabolic Mechanism Resolving the Paradox.” Appetite 48.2 (Mar. 2007): 135–38.

Payne, Martha E., and others. “Vascular Nutritional Correlates of Late-Life Depression.” American Journal of Geriatric Psychiatry 14.9 (Sept. 2006): 787–95.

ORGANIZATIONS

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

Nancy Gustafson, MS, RD, F.A.D.A., E.L.S.

Ruth A. Wienclaw, PhD

Diets

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

See also Nutrition counseling; Nutrition and mental health

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.

Dieting

It would be hard to find anyone in the United States, or in any other part of the Western world, who has not at one time gone on a weight-loss diet. Perhaps the most long-lived fad of our society, the diet craze has grown and expanded its influence until almost every issue of every popular publication contains at least one diet article and television talk shows regularly feature diet gurus and those offering weight loss testimonials. With little evidence that such diets work, and with quite a bit of evidence to the contrary, a multi-billion dollar industry has grown up around the modern obsession with thinness. Women are the vast majority of consumers in the diet industry, and, though men do diet, it is almost exclusively women who focus a significant portion of their time and energy on the effort to become thin.

Though Americans are constantly bombarded with the concept of thinness as an ideal of health and beauty, it is a relatively new concept that would have seemed laughable just one hundred years ago. Though standards of beauty have varied from culture to culture and from century to century, plumpness has widely been viewed as signaling health, success, and sensuality. Many modern cultures do not place the same value on thinness as much of western society. Some, such as those in Polynesia and east and central Africa, value fat women to the extent of fattening up daughters to make them more marriageable.

Human bodies evolved in response to a struggle to survive with an uncertain food supply. The ability to store fat was a valued genetic trait. As long ago as 30,000 to 10,000 B.C.E., statues like the so-called Venus of Willendorf show an ideal of feminine beauty that includes large thighs, broad buttocks and pendulous breasts. The Biblical book of Proverbs says, "He that putteth his trust in the Lord shall be made fat." Even in Medieval Europe, when the religious art showed lank, acetic Marys and Eves, the secular art pictured round, fleshy women, brimming with laughter and sexuality. A fat, dimpled buttock or thigh was a universal symbol of sex appeal.

On the contrary, thinness was viewed as a sign of weakness, disease, and poverty. Eighteenth-century diet specialist Jean-Anthelme Brillat-Savarin called thinness "a terrible misfortune" for a woman. "Every thin woman wishes to put on weight," he said, "This is an ambition that has been confided to us a thousand times." He obliged them by prescribing fattening diets. By the end of the nineteenth century, women had begun to slim their waists through the use of tightly laced corsets, but ample cleavage and voluminous hips were still very much the style, helped along by contrivances called farthingales, panniers, and bustles. These were wire frames worn under the clothes to add desirable inches (or feet) to hips and buttocks. Indeed, most changes deemed necessary in the body were effected by additions to the costume. Only later would women begin to consider the idea of altering the body itself.

As the 1900s began, the country was in an era of tremendous growth and change. The industrial revolution was bringing science into the day-to-day lives of common citizens. A feminist age was beginning as women entered the work force in unprecedented numbers and began to demand more rights. Along with these changes came a new look in women's fashions. The corsets and cumbersome contraptions were gone and so was the abundant flesh. By the 1920s women were supposed to be slim, straight, and boyish. Hair was bobbed, breasts and hips were bound, and women began to try to lose weight. Along with such extreme treatments as electrotherapy, tape-worm pills, and hot baths to melt fat off, miracle diets promised to fatten the scrawny as well as slim the stout.

Around the same time, the newly burgeoning insurance industry began to study the effects of weight and other features on longevity. Inspired perhaps by the fashion of thinness, researchers tended to ignore the evidence that the underweight and the tall had higher death rates too, and they only focused on the overweight. Even though their research methods were questionable and their samples included only the upper classes who had the money and inclination to purchase life insurance, the insurance tables were popularly accepted as fact in terms of optimum height-weight ratios. These tables have remained a standard by which modern people measure themselves, even though their recommendations have varied widely over the decades.

It was also around the 1920s that doctors began to abandon their condemnation of thinness as a sign of the common disorder "neurasthenia" and to attack excess weight as the cause of many health problems. Even then, there was not widespread belief that people could control their body size, and doctors worried that dieting, especially the dieting of young women, was dangerous to health.

The Roaring Twenties' dieting craze, which never penetrated much beyond the upper classes, waned during the late 1930s and early 1940s, as the poverty of the depression years deepened. But by the 1950s, the preference for thinness and disgust with fat was on its way to becoming a national obsession. This obsession was perhaps useful to a society which was trying to distract women from the increased responsibility they had been given during the war and refocus them on home, family, and fashion. The number of magazine articles about weight and diet skyrocketed, and fatness, which once had been viewed as a physical characteristic like any other, had become a vice and a moral failing. Weight loss products and diet foods began to appear on grocery shelves, and dieters bought them in huge quantities. Pharmaceuticals firm Mead and Johnson created an all-liquid diet food called Metrecal that boosted their earnings over 300 percent in the years between 1958 and 1960. Just as quickly, however, profits dropped again, as unsuccessful dieters moved on to try other products. Amphetamines, a fairly new drug about which little was known, were prescribed freely to women as a weight loss aid.

Diet books also began to appear, some with a health food bent, others purely fashionable. Exercise had long been seen as having a negative effect on weight loss because it stimulated the appetite, but modern experts made the case for exercise as an adjunct to a weight-loss diet. Fad and novelty diets began to pop up, often having nothing more to recommend them than sheer weirdness, but promising "miracle" results. The Drinking Man's Diet, offered permission to imbibe; the grapefruit diet ascribed extraordinary fat burning qualities to the acidic yellow fruit which was to be eaten several times a day. One diet prescribed only steak, another suggested eating foods high in fat. Americans were willing to try anything that promised results.

Medical opinions about the effects of obesity continued to follow closely the guidelines and research done by the insurance industry, even though that research was proved flawed and limited on many occasions. Since the major factor in body size seemed to be genetic, doctors began to prescribe weight-loss diets even for pregnant women and young children. As fat was seen as the result of moral flaws such as lack of willpower, it was also seen as a psychological problem, and fat people were sent to psychiatrists to seek the deep root causes of their body size.

The 1960s and 1970s saw the continued increase of the thinness obsession, perhaps more than coincidentally with the rise of a second wave of women's liberation. Some feminists speculate that each time women gained power and pushed for more rights, they were purposely distracted by a cultural insistence on an unattainable female body ideal. Women, though genetically predisposed to be fatter than men, have always borne the brunt of the weight-loss fad. Though some dieting occurs among men, it is far more common that even men who do not fit the media mold of beauty have little shame over exposing bellies and bare chests in public, while women, even admired models and actresses, experience shame and self-loathing about their bodies. Perhaps because men have had more economic and political power, it has been necessary for women to fit the mold most pleasing to men. If the eating disorders and obsession with dieting that women exhibit are reflected anywhere among men, it is among gay men, who have the same need that heterosexual women have to fit the male standard of beauty. Nowhere has that standard been challenged more strongly than within the lesbian community. Though not immune to cultural beauty standards, lesbians' relative independence from men has given them both room and incentive to question those standards. That questioning has led to pioneering work in the fat acceptance movement, which challenges the diet industry and medical establishment's demonization of fatness.

By the 1990s the diet fad has become so widespread that most Americans are continually on one sort of weight-loss plan or another, and most women consider themselves fat, no matter what their actual size. Studies have been done that show a high percentage of girls as young as eight years old have begun to diet. Fashion models appear acutely undernourished and even they must have their pictures airbrushed to remove offending flesh. Eating disorders such as anorexia (the rejection of food to achieve ever-increasing thinness) and bulimia (binge eating followed by forced vomiting or laxative-induced diarrhea) which once were rare, have become epidemic. Surgical procedures such as stomach-stapling and liposuction are in demand even though they are known to have dangerous or even deadly effects.

The media abounds with new "miracle" diets, and the diet business has grown from a few companies with names like Weight Watchers and Slenderella to a 50 billion dollar-a-year industry. With ads offering such perplexing promises as "Lose ten pounds for only ten dollars," these diet companies have perhaps finally achieved the perfect American solution to excess weight. If willpower, therapy, and even prayer don't work, one can buy weight loss.

The success of products like Metrecal in the 1950s has led to a boom in diet products and organizations. While some products like Slim Fast and Lean Cuisine specialize in diet food, others have jumped on the bandwagon by offering "lite" or "lo-fat" versions of their products. Soft drink companies were among the first to offer profitable diet alternatives. These are guzzled in astounding quantities by Americans of all sizes, even though their artificial sweeteners, first saccharin, then cyclamates, and most recently aspartame, have in some cases been found to have damaging effects on the body. Often, as in Metrecal's case, when a new product is introduced, there is a rush to try it. When it proves to be less than miraculous, sales may drop as consumers move on to the next new promise.

Another form of diet business is the dieter's organization or "club." Affluent dieters often pay high prices to attend spas and "fat farms" to help them lose weight. For middle and working class dieters there are more affordable alternatives. Organizations like Weight Watchers and Jenny Craig offer counseling and group support for a price, plus a line of food products that are required or strongly suggested to go with the program. The twelve-step approach of Alcoholics Anonymous is emulated by groups like Take Off Pounds Sensibly (TOPS) and Overeaters Anonymous, which tend to view fatness as a sign of addictive attitudes towards food and offer free support groups to combat the addiction.

Over the years, many weight-loss "gurus" have risen to media prominence, producing books or videos to promote their personal recommendation for weight loss. As early as 1956, Roy de Groot published his low-protein "Revolutionary Rockefeller Diet" in Look magazine, leading the way for Robert Atkins' Dr. Atkins' Diet Revolution in 1972, Herbert Tarnower's "Scarsdale" diet in 1979, and Jane Fonda's books and videos in the 1980s and 1990s. Trading on medical credentials or celebrity, these diet "experts" often become corporations in themselves, profiting handsomely from sales and public appearances.

Yet many Americans are still overweight. In fact, diets have never been successful at making fat people thin. Only about ten percent of dieters lose anything close to their goals, and only about half of those keep the weight off for an extended period of time. The body is an efficient processing machine for food and its response to the starvation message sent by dieting is to become even more efficient, thereby needing less food to maintain the same weight. The World Health Organization's definition of starvation is 1200 calories per day, the same intake as an average weight-loss diet. Even when caloric reduction causes the body to use stored resources, there is no guarantee that unwanted fat will be used. The body might as easily draw from muscle tissue, even from the brain or heart, with life-threatening results.

Some researchers claim that the rising numbers of fat people are caused by the incessant dieting practiced by most Americans. Each bit of weight loss causes the body to respond as it would to recurring famine, by storing food, and fat, more efficiently. Even aside from overtly dangerous diets, such as liquid protein diets or extreme 400 to 500 calorie diets, any sort of weight-loss diet can have seriously negative effects. Depression, irritability, and fatigue are frequent side effects, along with amenorrhea for women, muscle damage, and stress on liver, kidneys, and the cardiovascular system. In the long run, medical studies on the negative effects of being fat become useless, for, in a society where everyone diets, fat people, persecuted for being fat, often spend a large part of their lives dieting. It is difficult to separate the effect of weight on health from the effects of long-term dieting and from the stress of being fat in a culture that demeans fat people.

Though dieting has become so entrenched in American culture, some voices are being raised in protest. The fat-positive movement (also called the size-acceptance or size-diversity movement) is growing, energized by people who are no longer willing to devote their lives to fitting an impossible ideal. An anti-diet movement has arisen, drawing attention to the dangers of dieting with an annual International No-Diet Day. Concerned by the rising numbers (over 11 million in the 1990s) of young girls afflicted with anorexia and bulimia, some parents and educators are calling for more focus on raising the self-esteem of adolescent girls. However, surveys still report that a large percentage of women would prefer being run over by a truck or killed by a terrorist to being fat, and American culture has a long way to go to leave superficial values behind. Perhaps as long as there is still so much money to be made off of Americans' preoccupation with thinness, dieting will remain a lifestyle and an obsession.

—Tina Gianoulis

Further Reading:

Atrens, Dale. Don't Diet. New York, William Morrow and Company, 1988.

Bennett, William, and Joel Gurin. The Dieter's Dilemma: Eating Less and Weighing More. New York, Basic Books, 1982.

Chernin, Kim. The Obsession: Reflections on the Tyranny of Slenderness. New York, Harper and Row, 1981.

Seid, Roberta Pollack. Never Too Thin: Why Women Are Obsessed with Their Bodies. New York, Prentice Hall, 1989.

Diets

Definition

Humans may alter their usual eating habits for many reasons, including weight loss, disease prevention or treatment, removing toxins from the body, or to achieve a general improvement in physical and mental health. Others adopt special diets for religious reasons. In the case of some vegetarians and vegans, dietary changes are made out of ethical concerns for the rights of animals.

Origins

The practice of altering diet for special reasons has existed since antiquity. For example, Judaism has included numerous dietary restrictions for thousands of years. One ancient Jewish sect, the Essenes, is said to have developed a primitive detoxification diet aimed at preparing the bodies, minds, and spirits of its members for the coming of a "messiah" who would deliver them from their Roman captors. Preventative and therapeutic diets became quite popular during the late twentieth century. Books promoting the latest dietary plan continue to make the bestseller lists, although not all of the information given is considered authoritative.

Benefits

People who are moderately to severely overweight can derive substantial health benefits from a weight-loss

diet. A weight reduction of just 10 to 20 pounds can result in reduced cholesterol levels and lower blood pressure. Weight-related health problems include heart disease , diabetes, high blood pressure, and high levels of blood sugar and cholesterol.

In individuals who are not overweight, dietary changes may also be useful in the prevention or treatment of a range of ailments including acquired immunodeficiency syndrome (AIDS ), cancer, osteoporosis, inflammatory bowel disease , chronic pulmonary disease, renal disease, Parkinson's disease , seizure disorders, and food allergies and intolerances.

Description

The idea of a healthful diet is to provide all of the calories and nutrients needed by the body for optimal performance, at the same time ensuring that neither nutritional deficiencies nor excesses occur. Diet plans that claim to accomplish those objectives are so numerous they are virtually uncountable. These diets employ a variety of approaches, including the following:

• Fixed-menu: Offers little choice to the dieter. Specifies exactly which foods will be consumed. Easy to follow, but may be considered "boring" to some dieters.
• Formula: Replaces some or all meals with a nutritionally balanced liquid formula or powder.
• Exchange-type: Allows the dieter to choose between selected foods from each food group.
• Flexible: Doesn't concern itself with the overall diet, simply with one aspect such as fat or energy.

Diets may also be classified according to the types of foods they allow. For example, an omnivorous diet consists of both animal and plant foods, whereas a lactoovo-vegetarian diet permits no animal flesh, but does include eggs, milk, and dairy products. A vegan diet is a stricter form of vegetarianism in which eggs, cheese, and other milk products are prohibited.

A third way of classifying diets is according to their purpose: religious, weight-loss, detoxification, lifestyle-related, or aimed at prevention or treatment of a specific disease.

Precautions

Dieters should be cautious about plans that severely restrict the size of food portions, or that eliminate entire food groups from the diet. It is highly probable that they will become discouraged and drop out of such programs. The best diet is one that can be maintained indefinitely without ill effects, that offers sufficient variety and balance to provide everything needed for good health, and that is considerate of personal food preferences.

Fad diets for quick weight loss are coming under increasing fire, since dieters seldom maintain the weight loss. In 2001, researchers found that three times as many people on moderate fat weight loss diets stuck to their plan compared to those on traditional low-fat diets. Not only do many diets offer only short-term and rapid weight loss, some can be bad for the dieter's health. For instance, the American Heart Association made a statement in late 2001 questioning the value of high-protein, low-carbohydrate diets. The association said that the diets don't work over the long term and that they can pose some health risks to dieters. In 2003, these statements were largely supported. Though clinical trials showed that these types of diets worked in lowering weight without raising cholesterol for the short-term, many of the participants gained a percentage of the weight back after only one year. A physician group also spoke out about high protein diets' dangers for people with decreased kidney function and the risk of bone loss due to decreased calcium intake.

Low-fat diets are not recommended for children under the age of two. Young children need extra fat to maintain their active, growing bodies. Fat intake may be gradually reduced between the ages of two and five, after which it should be limited to a maximum of 30% of total calories through adulthood. Saturated fat should be restricted to no more than 10% of total calories.

Weight-loss dieters should be wary of the "yo-yo" effect that occurs when numerous attempts are made to reduce weight using high-risk, quick-fix diets. This continued "cycling" between weight loss and weight gain can slow the basal metabolic rate and can sometimes lead to eating disorders. The dieter may become discouraged and frustrated by this success/failure cycle. The end result of yo-yo dieting is that it becomes more difficult to maintain a healthy weight.

Caution should also be exercised about weight-loss diets that require continued purchases of special prepackaged foods. Not only do these tend to be costly and over-processed, they may also prevent dieters from learning the food-selection and preparation skills essential to maintenance of weight loss. Further, dieters should consider whether they want to carry these special foods to work, restaurants, or homes of friends.

Concern has been expressed about weight-loss diet plans that do not include exercise , considered essential to long-term weight management. Some diets and supplements may be inadvisable for patients with special conditions or situations. In fact, use of the weight loss supplement ephedra was found to cause serious conditions such as heart attack and stroke . In 2003, the U.S. Food and Drug Administration (FDA) was considering controlling or banning the supplement. In short, most physician organizations see fad diets as distracting from learning how to achieve weight control over the long term through healthy lifestyle changes such as eating smaller, more balanced meals and exercising regularly.

Certain fad diets purporting to be official diets of groups such as the American Heart Association and the Mayo Clinic are in no way endorsed by those institutions. Patients thinking of starting such a diet should check with the institution to ensure its name has not been misappropriated by an unscrupulous practitioner.

Side effects

A wide range of side effects (some quite serious) can result from special diets, especially those that are nutritionally unbalanced. Further problems can arise if the dieter is taking high doses of dietary supplements. Food is essential to life, and improper nutrition can result in serious illness or death.

Research & general acceptance

It is agreed among traditional and complementary practitioners that many patients could substantially benefit from improved eating habits. Specialized diets have proved effective against a wide variety of conditions and diseases. However, dozens of unproved but widely publicized "fad diets" emerge each year, prompting widespread concerns about their usefulness, cost to the consumer, and their safety.

Training & certification

A wide variety of practitioners provide advice on dietary matters. These range from unregulated, uncertified alternative practitioners, to registered dietitians, medical doctors, and specialists. Nutritional advice can also be obtained from home economists and from college or university nutrition departments.

Resources

PERIODICALS

"American College of Preventive Medicine Weighs in Against Fad Diets." Obesity and Diabetes Week (March 17, 2003): 7.

"Atkins Diet Vindicated But Long-term Success Questionable." Obesity, Fitness and Wellness Week (June 14, 2003): 25.

Cerrato, Paul C. "AHA Questions High-protein Weight-loss Diets" Contemporary OB/GYN 46, no. 12 (December 2001): 107-112.

"Healthy Fat Superior to Low-fat diet for Long-term Weight Loss" Obesity, Fitness and Wellness Week (November 10, 2001): 2.

"High-protein Diets Risky for Bones and Kidneys." Health Science (Spring 2003): 9.

Kirn, Timothy F. "FDA Probes Ephedra, Proposes Warning Label (Risk of Heart Attack, Seizure, Stroke)." Clinical Psychiatry News (April 2003):49.

ORGANIZATIONS

American Dietetic Association. 216 West Jackson Blvd., Chicago, IL 60606-6995. (312) 899-0040. http://www.eatright.org.

David Helwig

Teresa G. Odle

diets A diet is a pattern of food consumption which is followed by a population or an individual. The diets of populations are affected by local factors including geography, climate, food availability, culture, and religion, whereas the diets of individuals within populations are further influenced by factors such as socio–economic status, personal preference, and health considerations. To maintain life, all diets must supply the essential amounts of energy, protein, essential fatty acids, vitamins, and minerals, but these needs can be met by a wide variety of diets, each of which will be sufficient for growth, survival, and reproduction but may also have obvious or subtle effects on the long-term state of health.

Traditional diets

The traditional diets of populations around the world vary greatly. The diet of Inuit hunters in the Arctic is composed almost entirely of meat and fish, but most hunter-gatherers in other parts of the world obtain more food from gathering plants than from hunting animals. Pastoralists keep different animals according to where they live, varying from reindeer in the north to camels in hot arid areas, but they always have a diet rich in animal foods such as milk, meat, and blood. Peasant agriculturalists grow different staple crops according to local conditions, but usually have diets composed largely of plant foods with only small amounts of animal foods.

The traditional diets of populations have been followed for hundreds or thousands of years and, except in times of severe food shortage, are certainly compatible with the maintenance of health sufficient for the survival and growth of infants and children, and for successful reproduction. However, traditional diets are sometimes far from optimal and may be accompanied by serious nutritional disorders, from which the people may have suffered for many generations. For example, approximately one-fifth of the population of the world is at significant risk for developing iodine deficiency disorders; pellagra was formerly common in populations subsisting largely on maize due to deficiency in the vitamin niacin and the amino acid tryptophan; and high blood pressure and stroke are common in populations with a diet high in salt.

‘Western’ diets

The diets of affluent Western populations changed very rapidly during the twentieth century. In comparison with the diets of peasant agriculturalists, Western diets are usually much higher in animal protein and fat and much lower in starch and dietary fibre, and ample food is available throughout the year. It is well known that Westernization of the diet is usually associated with increases in the rates of some diseases, such as ischaemic heart disease, large bowel cancer, and obesity, but it should also be appreciated that Westernization is generally accompanied by an increase in overall life expectancy and by decreases in the rates of some diet-related diseases such as stomach cancer, as well as decreases in the incidence of most infectious diseases.

Diets for health

Within Western populations, the word ‘diet’ is commonly used to refer to patterns of food consumption which are followed for reasons of health or for ethical or religious reasons (vegetarian and vegan diets are discussed in separate entries). A good diet is of profound importance for the maintenance of good health; nutritional deficiencies severe enough to cause obvious diseases such as scurvy and pellagra are now very rare in Western societies, but diet is a major determinant of the risk for developing many of the commonest fatal diseases, including ischaemic heart disease, stroke, and cancers of the large bowel and stomach.

The commonest type of diet followed for health reasons is one intended to cause weight loss in the treatment of overweight, and the term dieting is often assumed to refer to a weight-reduction diet. Numerous types of weight-reducing diets have been marketed. Most will cause some initial weight loss, but this is difficult to maintain because obesity is associated with the typical Western lifestyle of low physical activity and constant availability of highly palatable, energy-dense foods.

After obesity, the most common reason for requiring dietary changes is a high blood cholesterol concentration and associated ischaemic heart disease. The blood cholesterol concentration is increased by diets high in saturated fat and cholesterol. Reducing the intake of these factors causes a reduction in blood cholesterol, but most individuals find it difficult to change their diet sufficiently to have more than a small effect. Other diets followed for health reasons include low salt diets for the reduction of raised blood pressure and gluten-free diets for individuals with coeliac disease.

High-fibre diets have become popular since the work of Denis Burkitt and others in the early 1970s. Fibre is now defined as non-starch polysaccharides, and is supplied by unrefined cereals, vegetables, and fruits. Fibre has several benefits, including the prevention of constipation and probably reducing the risk for coronary heart disease and cancer of the large bowel.

The topic of diet and health is covered extensively by the media and many people are confused as to what constitutes a healthy diet. Government bodies in many countries now make dietary recommendations. In Britain, the Committee on Medical Aspects of Food Policy (COMA) reviews various aspects of the relationship of diet with health. In their recent report on nutritional aspects of cardiovascular disease, COMA made several recommendations for adults, including that total fat and saturated fat should provide no more than 35% and 10% respectively of food energy, that average salt intake should be reduced to 6 g per day, and that the consumption of vegetables, fruit, potatoes, and bread should be increased by at least 50%. These recommendations reflect a growing consensus that a healthy diet should be based on starch-rich foods such as cereals and should include generous quantities of fruit and vegetables. This type of diet is also rich in dietary fibre and many vitamins, and the emphasis is on supplying these nutrients from ordinary foods rather than from special high-fibre foods or vitamin supplements.

Future needs — more science in the choice of diets for populations and individuals

Traditional diets have evolved out of necessity, to be sufficient for life, but are often far short of ideal. Western diets have come from traditional roots but have been radically changed by affluence, developments in agriculture and food processing, advertising, fashion, etc. Most people now eat a diet determined by a mixture of tradition, availability, convenience, taste, and peer pressure. The health effects of the resulting mix are themselves mixed, with some diet-related health problems decreasing and others increasing. We already have sufficient knowledge to do much better than this, and need to introduce more science into all the components of society which affect food consumption, including agricultural policy and the education of children, caterers, and politicians. Evidence from sound scientific studies should be continually fed into society with the aim of producing improvements in the health of the population and in the optimal use of land and other resources.

Tim Key

Bibliography

Report of the Cardiovascular Review Group Committee on Medical Aspects of Food Policy (1994). Nutritional aspects of cardiovascular disease. HMSO, London.