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.

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

diet is fundamental to human existence. What people eat or choose to eat is conditioned by the food‐producing capabilities of the country, by trade, income, taste, custom, and culture. In Ireland these influences for many centuries led to a diet dominated by pastoral products. Traditional Gaelic society supported a system of semi‐nomadic pastoral farming because Ireland was climatically suited to the rearing of livestock. Meat of all types was eaten in large quantities. Milk in liquid, solid, and semi‐solid forms was an important adjuvant, and sour milk, in varying degrees of viscosity, was consumed. Especially popular were curds called ‘bonaclabbe’. Butter also formed an essential part of the daily diet. People ate fistfuls of rancid butter rolled in oats, spread butter on oatcakes, and even ate butter on its own. The importance of butter is indicated by the practice of burying stores for future consumption in cool, damp bogs.

Gaelic society was aware of the value of cereals as a useful component of the diet, though until the end of the 16th century the role of tillage crops was no more than as a supplement to meat and dairy produce, particularly in winter. The exception was those areas which overlapped with Anglo‐Norman settlements, where colonists had from the 12th century introduced a different dietary pattern of gruels and puddings based on cereals, peas, and beans, along with bread.

During the course of the 17th century cereals assumed a more central place in diets as arable farming expanded. The process was assisted by the continual influx of people from England and Scotland in the wake of the Munster and Ulster plantations. This new wave of colonization wrought more fundamental dietary changes than earlier influxes of migrants. English colonial theory required that land be put under the plough. Arable husbandry spread in the east, and the commercial cultivation of oats and other grains developed in many places from early in the 17th century. The spread of tillage throughout Ireland was gradual. Nevertheless, by the end of the century the land was yielding a variety of grains, fruits, and sweet herbs. Fisheries had been established along the coasts, netting a variety of bass, mullet, eels, hake, herrings, oysters, cockles, and mussels.

The newcomers to 16th‐century Ireland brought with them, not merely their farming methods and their money, but also their prejudices and their tastes. The consumption of blood, in a jellified form or mixed with butter, oats, or salt, was an aspect of Gaelic cuisine that particularly repelled English observers. They were appalled, too, by the willingness of the native population to devour animal entrails and to eat carrion and horse meat, by their partiality for warm milk straight from the cow, adorned with straw and worse, by their habit of eating rancid butter, by their unhopped ale, and by their preference for oatcakes and gruels rather than good wheaten bread.

Changes in taste were powerfully accelerated by the commercial and political developments of which colonization was a part. Several forces were at work. One was a changing perception of food as a commodity. In Gaelic society much food had been distributed as tributes given to overlords or made over to them as rent payments. The lordship system dissolved slowly, although it was still partly intact on the eve of the rising of 1641. Gradually, however, market mechanisms took over and food became a commercial commodity, its consumption governed by the price and by the incomes and preferences of buyers.

By the 18th century a class distinction in consumption patterns had become pronounced. The diet of the Irish gentry evolved to resemble that of their English counterparts. Their consumption of sugar, tea, coffee, raisins, currants, and confectionery rose sharply, reflecting the growing taste for luxury foods. Although per capita wine consumption declined, that of whiskey and beer increased (see drink). The consumption of meat and bread remained important, together with milk, butter, and cheese, but cereals, vegetables, fruit, and other foods were all by now fully integrated into the diet.

Meanwhile, at the beginning of the 18th century, the lower ranks of society still had diets composed principally of dairy products, although with supplements of vegetables and grains. This varied fare was short‐lived; contrary trends were at work. As the century progressed labouring‐class diets became simpler and distinct from the eating patterns of their social superiors, the process intensifying as the century progressed. By the beginning of the 19th century the poor throughout the country were subsisting principally on potatoes and milk. Potatoes were consumed in very large quantities; estimates range from 10 to 15 pounds daily for adult men. The potato had become the staple food of at least one‐third of the population on the eve of the Great Famine. During spring and early summer whole milk was sometimes drunk, though skimmed or buttermilk were the more common beverages. Butter was produced for market, leaving the less nutritious buttermilk liquid for home consumption. During the ‘hungry months’ of summer two foods, oatmeal and herrings, filled the hiatus between the end of the old season's potato crop and the new harvest. There was a regional pattern to oatmeal consumption; more was eaten in northern and eastern counties than elsewhere. Herrings were eaten throughout Ireland, although less extensively in the midlands. Other foods had become occasional, peripheral, and luxurious.

As long as potato harvests were abundant and high yielding, the Irish poor were well fed. Crop yields, however, were variable and throughout the 18th and first half of the 19th centuries the poor occasionally teetered on the brink of famine. The Great Famine demonstrated just how frail the dietary regime had become. Between 1845 and 1849 the crops failed disastrously in three seasons out of four because of a fungal disease, and the length of the crisis created famine conditions of great severity. In terms of diet, the Famine proved a catalyst, accelerating changes in the food‐consumption patterns of the labouring classes as their confidence in the ability of the potato to meet dietary requirements waned.

After the Famine the determinants of dietary change were many. Living standards rose, particularly among the poor. Per capita incomes tripled between the 1840s and 1914. Despite higher household expenditure on rent, advances in wages kept ahead of prices; and from the 1870s to the end of the 19th century food prices were generally falling. Consequently the food‐consumption patterns of the poor became more varied and the contrast between their diets and those of their social superiors narrowed, especially in towns.

The rise in purchasing power was reflected in the increasing proportion of food bought in shops and in the growing consumption of imported as opposed to home‐grown foods. Shopkeepers often fulfilled a dual, and in some cases triple, role in the food economy of the poor. Not only were they the suppliers of food, but in remote areas they acted as middlemen, accepting eggs and butter for the export market in exchange for Indian meal, tea, and sugar. They also provided credit on which the poor depended.

The spread of railways in the second half of the 19th century greatly facilitated the distribution of groceries and other items to rural areas. As a result sweet strong tea replaced milk as the main beverage, and even the very poorest demanded tea of a high quality. Imports of cheap American wheat stimulated greater consumption of bread, home baked or purchased from bakers' vans that toured the countryside. Roller milling produced several flour grades, though as with tea only a high quality was acceptable (see flour milling). Indian meal, a remnant of famine relief, was popular until the end of the 19th century, sometimes mixed with flour for bread making or added to oatmeal for porridge. Fatty American bacon was favoured for its flavour and cheapness. In very poor households bacon fat was rendered down to a sauce for pouring over vegetables. Inferior cuts of meat became weekly treats rather than Christmas and Easter delicacies.

Meanwhile the dominance of the potato declined, though it was still an important item in the clined, though it was still an important item in the daily diet, particularly in the west. A stark demonstration of this pattern was the reappearance of famine conditions accompanied by disease in western counties at the end of the 1870s. Relief committees were set up to dispense Indian meal rations to the starving. A large‐scale catastrophe was averted only because potato dependency was confined to that region.

Dietary changes were not always accompanied by improvements in nutritional standards. Paradoxically, at the lower end of the income scale the transition from a monotonous menu to more varied fare resulted in a fall in nutritional quality. The pre‐Famine potatoes‐and‐milk regime had been rich in almost all nutrients, but when it was replaced by cereals, bread, butter, and tea the nourishment was inferior. This new pattern was particularly prevalent in towns, where death rates from diseases of poverty were high. Contemporary commentators noted the deterioration in the nation's health and many ascribed it to poor diet.

By the opening years of the 20th century more dietary improvements were evident. Variety increased further, especially among better‐paid urban labourers. Differences between urban and rural diets nevertheless also narrowed as the century progressed, as did the disparity between social classes.

Today most food is bought from retail outlets. Extensive consumer choice has resulted from developments in food‐processing technology, trading networks that have become worldwide, and a revolution in the kitchen which has affected both storage facilities and cooking methods. Certain features of the old dietary pattern, however, can be discerned. Potatoes maintain an important role in the diet. And the partiality of the Irish for pastoral products has been retained, prompting the medical profession to speculate on whether the high intake of saturated fat, particularly in the form of butter, contributes to the high incidence of cardiovascular disease.

E. Margaret Crawford

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.

Purpose

People who are moderately to severely overweight can derive substantial health benefits from a weight-loss diet. A weight reduction of just 10-20 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 also may be useful in the prevention or treatment of a range of ailments including acquired immuno deficiency syndrome (AIDS), cancer, osteoporosis, inflammatory bowel disease, chronic pulmonary disease, renal disease, Parkinson's disease, seizure disorders, and food allergies and intolerances.

Description

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. Preventive and therapeutic diets became 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.

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 also may be classified according to the types of foods they allow. For example, an omnivorous diet consists of both animal and plant foods, whereas a lacto-ovo-vegetarian diet permits no animal flesh, but includes 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. Many controversies have arisen in the past over the benefits and risks of high-protein, low carbohydrate diets such as the Atkins diet. Most physician groups and health organizations have spoken out negatively against the program. 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 also should 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 also may 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. People 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 and 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.

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.

"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〉.

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.

diet. The Buddha's advice concerning dietary habits is addressed primarily to those who have embraced the monastic life rather than to lay society. An important principle underlying Buddhist monasticism is that monks should be dependent upon the laity for alms and should go out daily into the local community to beg for food. It is a familiar sight in the Buddhist countries of south Asia to see a line of saffron-clad monks walking soberly in single file from house to house and pausing with downcast eyes while offerings of food are placed in their bowls by the laity. After completing their round the monks return to the monastery where they must consume their food before midday. Thereafter, except in case of illness, they may take only liquids before the next day. The Buddha commended the practice of eating but once a day for its benefits in terms of overall mental and physical well-being.

As regards the type of food that may be consumed, the general principle is that monks should accept with gratitude whatever they are given and not be selective in preferring or rejecting particular dishes. In Theravāda Buddhism there is no prohibition on eating meat providing that the monk has not ‘seen, heard or suspected’ that the animal was slaughtered specifically on his behalf, thus avoiding complicity in the breaking of the First Precept (see pañca-śīla) against taking life. To understand this, one must first separate the issues of killing animals from that of eating meat. While the first is definitely demeritorious and productive of bad karma, the second may not be. The Buddha himself is said to have died after consuming pork, although the precise nature of this dish has been disputed (see sūkara-maddava). Since Buddhism is concerned primarily with the effect that moral actions have on the development of mental states and habits, it observes that actually killing an animal requires a state of mind characterized by anger, cruelty, or indifference, while simply eating meat carries no such strong signature. Thus, the Buddha did not categorically prohibit his followers from eating meat, even when it was suggested to him as a way of intensifying the religious practice of the community. Ten specific kinds of flesh, however, were thought to be inappropriate for human consumption, for instance, the flesh of elephants, tigers, and serpents. Monks and lay-people in Theravāda countries still consume meat although they may refrain from it on certain days and they also regard the occupation of butchery as being a form of wrong livelihood. Thus, early Buddhism shows what might be termed a mixed attitude: it recommends that no one make their living as a hunter or butcher, and certainly commends those who undertake a commitment to vegetarianism, but constantly asks that those who do so examine their motives and thoughts for any trace of rigid attachment to views and precepts, and does not tar those who eat meat with the same brush as those who produce the meat. As well as the Theravāda countries, this is especially true in Tibet and Mongolia, where the harsh and cold climate make the mass adoption of a vegetarian lifestyle impractical. Meat-eating was accepted in Tibetan Buddhist circles on account of the lack of vegetable produce in Tibet, and today even the Dalai Lama does not follow a wholly vegetarian diet.

The advent of Mahāyāna in India saw a movement towards the total abstention from meat-eating as this was felt to contradict a Bodhisattva's cultivation of compassion. Additionally, a number of Mahāyāna texts such as the Nirvāṇa Sūtra and the Laṅkāvatāra Sūtra are quite specific in their condemnation of meat-eating, as the tathāgata-garbha or Buddha-nature doctrines they teach imply that all living beings are embryonic Buddhas. The popularity of these texts in east Asia has resulted in almost universal vegetarianism among members of the Saṃgha. In east Asian cultures, one of the standard ways of caricaturing wayward clergy and monasteries was to accuse them of ‘eating meat and drinking wine’. China has kept to this practice very strictly, and has thus developed a very sophisticated and tasty repertoire of vegetarian cuisine, all the more surprising since the same scripture also teaches (as does the Vinaya) the avoidance of the Five Pungent Herbs (onions, garlic, scallions, leeks, and chives). The term ‘vegetarian’ is not entirely accurate in describing the ideal diet among Buddhists in east Asia, since the term implies only the avoidance of meat. Although the ideal Buddhist diet in China, Japan, Korea, and Vietnam certainly proscribes meat, the term used, chih su (‘eat vegetarian’) or su shih (‘vegetarian diet’) also indicates an avoidance of alcohol and the Five Pungent Herbs. The proscriptions on meat and alcohol are explained as fulfilling the requirements of several sets of rules, including the Five Precepts for laymen (pañca-śīla) and the Ten Novice's Precepts against killing and taking intoxicants. The rule against the Five Pungent Herbs is derived from the eighth fascicle of the Laṅkāvatāra Sūtra, which explains that these are very ‘hot’ vegetables that will act as an aphrodisiac and make practice difficult, in addition to which they make the breath foul, which drives away any potential audience one might have for preaching the Dharma, drives away protective deities, and attracts demons. Japan and Korea, while sharing this concern for vegetarianism early in their history, have in recent centuries been more tolerant of meat-eating among the clergy, while still admiring vegetarianism as an additional discipline that some may choose.

diet food and drink regularly consumed for nourishment. Nutritionists generally recommend eating a wide variety of foods; however, some groups of people survive on a very limited diet. The traditional Eskimo diet, for example, depended heavily on meat, but Eskimos ate nearly all of the animal; organ meats are rich in vitamins and minerals. Vegetarians exclude meat (and sometimes by extension dairy products) from their diet, often for philosophical reasons. Others exclude only red meat, but eat poultry and dairy products. To maintain a healthy diet, vegetarians need to eat a wide variety of plants whose nutrients complement each other, providing a balance of amino acids and vitamins.

Cultural, Regional, and Practical Factors

Until the advent of refrigeration , the most important factor in a person's diet was availability; diets varied according to animal migrations and the growing seasons of fruits, nuts, and vegetables. Another factor in food selection can be religion. Muslims, for example, are forbidden to drink alcohol.

Diets vary throughout the world. North Africa, with many Muslims, and the Middle East have similar diets. A starchy food (see starch ), such as rice, boiled and pounded yam mush, or cassava, is often accompanied by a spicy stew of fish or chicken with vegetables. Other popular dishes include curries, kebabs (marinated meat threaded on a stick and roasted), couscous (steamed wheat semolina), falafel (a spiced fritter), and yogurt. Many Asian diets are based on rice, which is often served with bite-size vegetables and meats accompanied by spicy seasoning. In Europe, bread is often the main starch, but Italy is noted for pasta , a nutritious noodle made from wheat and usually topped with a sauce, such as a small serving of cooked tomatoes garnished with cheese. In Scandinavia, fish in general, and herring in particular, are main staples of the diet.

Food has always been subject to cross-cultural influences, often as a result of colonization and migration of people. Thus, French influences can be seen throughout Asia, particularly in Japan and Indochina; Dutch influences in Indonesia and South Africa; and Indian influences throughout the Commonwealth of Nations. Certain foods, such as dumplings, are found in slightly different forms in all cultures. North American cuisine is an amalgam of Native American foods, such as corn-on-the-cob, and immigrant cuisines, including that of Africans.

Diet in the Twentieth Century

In the 20th cent. diets have been transformed by refrigeration, improved and faster transportation, advances in food preservation , and new farming methods that prolong the growing season and increase the yield per acre. As a result, foods are available more regularly, items purchased in one season can be frozen and consumed in another, and prices have become more competitive. After World War II, increased advertising, particularly on television, and the growing number of households in which all adults are employed, contributed to an increased consumption of unhealthy fast foods. Efforts in the 1980s and 90s by health experts to educate the public about the importance of a healthy diet has had some impact. People are eating more fruits, grains, and vegetables, and less red meat, and are aware of the need to control their weight. The latter has given rise to many ineffective, and sometimes dangerous, fad diets that do not provide all of the necessary daily nutrients. Successful weight control requires a carefully planned regimen of exercise combined with a diet based on the nutrition information supplied by the U.S. Dept. of Agriculture's Food Guide Pyramid (see food pyramid ).

Bibliography

See D. and P. Von Welanetz, The Von Welanetz Guide to Ethnic Ingredients (1982); J. Newman, Melting Pot: An Annotated Bibliography and Guide to Food and Nutrition Information for Ethnic Groups in America (1986); S. Quandt and C. Ritenbaugh, Training Manual in Nutritional Anthropology (1986); B. Griggs, The Food Factor: An Account of the Nutrition Revolution (1988).

dieting While one can diet to gain weight, or for specific physiological needs such as allergies or diabetes management, ‘dieting’ tends to refer to the process of manipulating food intake and energy output in order to reduce body weight for health or aesthetic reasons. To reduce weight, fewer calories than the body needs are ingested, forcing the body to obtain its energy from fat stores. To lose 1 lb per week, about 3500 kcal, (the weight of 1 lb of fat tissue) must be subtracted from the diet.

But the Latin root diaeta, ‘a way of life’, more accurately describes the daily realities of contemporary dieters. Fostered by Western medical and beauty standards, which prize slenderness, a 30 billion dollar diet industry has produced a wealth of diet plans ranging from hazardous fad diets to the nutritionally healthful. Recent research has emphasized the efficacy of drug therapies such as amphetamines and leptin, but the potential side-effects continue to pose serious problems. Since the majority of people who lose weight via dieting eventually gain it back, dieting has become a constant way of life for large numbers of Western people.

Dieting, particularly in order to achieve a thin ideal, only makes sense in the midst of affluence. Where food shortages endure, dieting (versus fasting for religious or cultural reasons) holds little value. On the other hand, affluent Western societies admire successful dieters for their self-discipline and willpower, as well as for their slim bodies.

Diet regimens, including those for weight loss, have existed for centuries, but modern dieting gained popularity in the late nineteenth and early twentieth centuries. Scientists who turned their attention to nutrition in the nineteenth century began to argue against overeating. Researchers such as Wilbur Atwater and Ellen Swallows ‘discovered’ vitamins, minerals, and calories as well as an understanding of how the body converted fat into energy. From this knowledge, the ‘new nutritionists’ laid the groundwork for modern dieting. They advocated lower body weights and smaller meals, and encouraged people to make dietary decisions based on the chemical composition of food (its nutritional value) versus taste or appearance. They encouraged everyone to count calories. Though invisible to the naked eye, excess calories would pile on very visible fat.

At the same time, a new, slender ideal of beauty, especially for women, gained cultural prominence. As historian Lois Banner has pointed out, in the late nineteenth century several popular ideals of female beauty, including robust and curvaceous images, competed for public attention, but by the 1920s, the slim-hipped, small-breasted, straight-lined flapper became the popular ideal. Though the exact dimension and shape of beauty ideals have shifted, the thin standard has never waned.

Margaret A. Lowe

Bibliography

Banner, L. (1983). American beauty. Knopf, New York.
Schwartz, H. (1987) Never satisfied: a cultural history of diets, fantasies, and fat. Collier–Macmillan, London.

Dieting

The term dieting refers to restrictive eating or nutritional remedies for conditions such as iron-deficiency anemia , gastrointestinal diseases, pernicious anemia, diabetes , obesity , or failure to thrive . Someone can be on a heart-healthy diet that encourages the consumption of reasonable amounts of whole grains and fresh fruits, vegetables, beans, and fish, but limits foods high in saturated fat and sodium, or one can be on a weight loss diet. Examples of weight loss diets include: the Atkins New Diet Revolution, the Calories Don't Count Diet, the Protein Power Diet, the Carbohydrate Addict's Diet, and Weight Watchers. There is a lack of research, however, on whether these diets (except for Weight Watchers) are helpful, especially over the long term (defined as two to five years from the date of weight loss).

The recommended approach to dieting for weight loss is to eat in moderation so as to control calories (do not go below 1,200 per day) and to increase activity to lead to a gradual, safe weight loss. A recommended method is to decrease calories each day by 125 (the amount in a small soft drink or full cup of juice) and to increase energy expenditure by 125 (walking for about 30 minutes). That is, a 250-calorie deficit a day should result in about a one- to two-pound weight loss over the course of a month. The goal is to slowly change eating and exercise routines and maintain a lifelong healthy weight. Quicker weight losses are hard to maintain. Most people can lose weight on any diet, even on fad diets, but the trick is to keep the weight off.

So-called fad diets are diets that come and go in the marketplace and are typically deficient in various ways. For example, they may lack variety (e.g., the Grapefruit Diet, the Cabbage Soup Diet), be too low in calories and protein (the Rice Diet), and/or simply too bizarre (the Rotation Diet for food allergies ). People should be especially wary of any "breakthrough" quick-fix diets. If a diet sounds too good to be true, it probably is.

Delores Truesdell

Bibliography

Alford, B. B.; Blankenship, A. C.; and Haen, R. D. (1990). "The Effects of Variations in Carbohydrate, Protein, and Fat Content of the Diet upon Weight Loss, Blood Values, and Nutrient Intake of Adult Obese Women." Journal of the American Dietetic Association 90:534–540.

Golay, A., et al. (1996). "Similar Weight Loss with Low- or High-Carbohydrate Diets." American Journal of Clinical Nutrition 63:174–176

Leeds, M. J. Nutrition for Healthy Living. WCB McGraw-Hill.

Ornish, D.; Scherwitz, L. W.; Billings, J. H.; et al. (1998). "Intensive Lifestyle Changes for Reversal of Coronary Heart Disease." Journal of the American Medical Association 280:2001–2007.

Internet Resource

Larsen, Joanne. "Fad Diets." Available from <www.dietitian.com>

Diet

The term diet refers to a person's pattern of eating and drinking. Diet is influenced by many factors, including income, culture, religion, geographic location, and lifestyle. A balanced diet contains food from several food groups and supplies the body with the energy and essential nutrients it needs (as defined by the Food Guide Pyramid and Dietary Reference Intakes ).

The Food Guide Pyramid lists food categories and serving recommendations. Dietary Reference Intake values provide a range of dietary recommendations, including the Recommended Dietary Allowances (RDAs), which provide the daily intake needed to meet the needs of "nearly all healthy persons." Dietary recommendations, and how they are represented, vary around the world. Most, however, convey a common message: balance, variety, and moderation in food choices.

see also Eating Habits; Dietary Reference Intakes; Food Guide Pyramid; Recommended Dietary Allowances.

Delores Truesdell

Bibliography

Brown, Judith (2002). Nutrition through the Life Cycle. Belmont, CA: Wadsworth.

Internet Resource

United States Department of Agriculture, Food and Nutrition Center. "Food Guide Pyramid." Available from <http://nal.usda.gov/fnic>

di·et¹ / ˈdī-it/ • n. the kinds of food that a person, animal, or community habitually eats: a vegetarian diet | a specialist in diet. ∎  a special course of food to which one restricts oneself, either to lose weight or for medical reasons: I'm going on a diet. ∎  [as adj.] (of food or drink) with reduced fat or sugar content: diet soft drinks. ∎ fig. a regular occupation or series of activities in which one participates: a healthy diet of classical music. • v. (di·et·ed , di·et·ing ) [intr.] restrict oneself to small amounts or special kinds of food in order to lose weight: it's difficult to diet. DERIVATIVES: di·et·er n. di·et² • n. a legislative assembly in certain countries. ∎ hist. a regular meeting of the states of a confederation. ∎  Scots Law a meeting or session of a court.

diet Range of food and drink consumed by an animal. The human diet falls into five main groups of necessary nutrients: protein, carbohydrate, fat, vitamin, and mineral. An adult's daily requirement is about one gram of protein for each kilogram of body weight. Beans, fish, eggs, milk, and meat are important protein sources. Carbohydrates (stored as glycogen) and fat are the chief sources of energy and are found in cereals, root vegetables and sugars. Carbohydrates make up the bulk of most diets. Fats are a concentrated source of energy and aid the absorption of fat-soluble vitamins (vitamins A, D, E, and K). Water and minerals, such as iron, calcium, potassium, and sodium, are also essential.

diet The food requirements of an organism. The foods that constitute the human diet should contain vitamins, mineral salts (see essential element), and dietary fibre as well as water, carbohydrates and fats (which provide energy), and proteins (required for growth and maintenance). A balanced diet contains of the correct proportions of these nutrients, which will vary depending on the age, sex, body size, and the level of activity of the individual. An inadequate supply of different food types in the diet can lead to malnutrition.

diet Strictly, a diet is simply the pattern of foods eaten; the normal or habitual intake of food of an individual or population. Commonly used to mean a modified pattern of food consumption for some special purpose, e.g. a slimming, therapeutic, or low‐salt diet (see salt‐free diets) and sometimes named for the person who originated it.

diet 1 food XIII; customary or prescribed course of food XIV. — (O)F. diète — L. diæta — Gr. díaita course of life.
Hence diet vb. XIV. So dietary course of diet XV; adj. XVII. — medL. diætārium.

diet 2 †day's journey; appointed day or time, meeting, session XV; metal scraped from gold and silver plate assayed day by day at the Mint XVII. — medL. diēta day's journey, allowance, work, wages.

diet (dy-ĕt) n. the mixture of foods that a person eats. balanced d. a diet that contains the correct proportions of all the nutrients.

Diet. See Food and Diet.

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