Encyclopedia of food and culture. Volume 3: Obesity to zoroastrianism, index

710 Pages·2003·22.104 MB·English

by  Solomon H. Katz (editor in chief), William Woys Weaver (associate editor)

SCRIBNER LIBRARY OF DAILY LIFE
VOLUME 3:
Obesity to Zoroastrianism,
Index
Solomon H. Katz, Editor in Chief
William Woys Weaver, Associate Editor
Encyclopedia of Food and Culture
Solomon H. Katz, Editor in Chief
William Woys Weaver, Associate Editor
© 2003 by Charles Scribner’s Sons ALL RIGHTS RESERVED For permission to use material from this
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LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA
Encyclopedia of food and culture / Solomon H. Katz, editor in chief ;
William Woys Weaver, associate editor.
p. cm.
Includes bibliographical references and index.
ISBN 0-684-80568-5 (set : alk. paper) — ISBN 0-684-80565-0 (v. 1) —
ISBN 0-684-80566-9 (v. 2) — ISBN 0-684-80567-7 (v. 3)
1. Food habits—Encyclopedias. 2. Food—Encyclopedias. I. Katz, Solomon H., 1939-
II. Weaver, William Woys, 1947- III. Title.
GT2850 .E53 2003
394.1’2’097303—dc21 2002014607
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
O
OATS. See Cereal Grains and Pseudo-Cereals. in women, of 35 inches (88 cm) or more, is the thresh-
old for defining central obesity (Table 1).
OBESITY. Obesity and overweight now affect more Prevalence of Overweight
than 50 percent of adult Americans. Diabetes mellitus, More females than males are overweight at any age. The
hypertension, heart disease, gallbladder disease, and some frequency of overweight increases with age to reach a
forms of cancer result from obesity. Whether these dis- peak at forty-five to fifty-four years in men and at age
eases are yet present or not, the obese individual should fifty-five to sixty-four in women. The National Health
be encouraged to lose weight by appropriate methods to and Nutrition Examination Survey (NHANES) con-
reduce the future likelihood that they will develop. Meth- ducted by the U.S. government (published in 1993) found
ods of weight loss include diet, nutritional education, a BMI of 25 or more in 59.4 percent of men age twenty
self-help groups, and behavioral change. Under some cir- years or older and in 50.7 percent of women over the age
cumstances drugs or surgery may be considered. of twenty years. The prevalence of obesity (BMI 30 or
more) was 19.5 percent in men and 25.0 percent in
women. The incidence of obesity continues to increase
Definition and Measurement of Obesity
dramatically in the United States and elsewhere. A num-
Obesity and overweight are best defined using the body
ber of factors including age, sex, and physical inactivity
mass index (BMI). This index is determined by dividing
influence the amount of body fat.
body weight in kilograms by the square of the height in
meters: BMI = W/H2. The normal rate for BMI is 18.5 At birth, the human infant contains about 12 per-
to 25. A BMI between 25 and 30 kg/m2is defined as over- cent body fat. During the first years of life, body fat rises
weight and a BMI above 30 kg/m2 is defined as obesity rapidly to reach a peak of about 25 percent by six months
(Table 1). Visceral fat can be used as an index of central of age and then declines to 18 percent over the next ten
adiposity. An increase in visceral fat reflects central obe- years. At puberty, there is a significant increase in the
sity and increases health risks. The waist circumference percentage of body fat in females and a decrease in males.
is used to assess the amount of visceral obesity. A waist By age eighteen, males have approximately 15 to 18 per-
circumference in men of 40 inches (102 cm) or more, and cent body fat, and females have 25 to 28 percent. Be-
TABLE 1
Classification of overweight and obesity by BMI, waist circumference, and associated disease risk
Disease risk* relative to normal weight
and waist circumference
Obesity Men = 102 cm (= 40 in) >102 cm (>40 in)
BMI kg/m2 class Women = 88 cm (= 35 in) >88 cm (>35 in)
Underweight 18.5 – –
Normal + 18.5–24.9 – –
Overweight 25.0–29.9 Increased High
Obesity 30.0–34.9 I High Very High
35.0–39.9 II Very High Very High
Extreme Obesity = 40 III Extremely High Extremely High
*Disease risk for type 2 diabetes, hypertension, and CVD.
+Increased waist circumference can also be a marker for increased risk even in persons of normal weight.
Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report. National Institutes of Health.
Obes Res 1998;6 Suppl 2:51S–209S.
1
OBESITY
mellitus, certain cancers, reproductive disorders, gall-
bladder disease, and sudden death.
The insulin-resistant state or metabolic syndrome is
strongly associated with visceral fat. It may include con-
sequences such as glucose intolerance or type 2 diabetes
mellitus, hypertension, polycystic ovarian syndrome, dys-
lipidemia (the state of abnormal—either higher or
lower—values for blood fats), and other disorders. These
are often responsive to weight loss, especially when this
is achieved early and the loss is maintained.
Development of Obesity
Several mechanisms lead to obesity, including neuroen-
docrine imbalances, particular drugs, diet, reduced en-
ergy expenditure, and genetic factors that lead to certain
syndromes and predisposition to obesity. Obesity can fol-
low damage to the hypothalamus in the brain, but this is
rare. Cushing’s disease is somewhat more common and
can result in obesity. Treatment should be directed at the
cause of the increased formation of adrenal corticos-
teroids.
Treatment of diabetics with insulin, sulfonylureas, or
thiazolidinediones (but not metformin) can increase
hunger and food intake, resulting in weight gain. Treat-
ment with some antidepressants, anti-epileptics, and
neuroleptics can also increase body weight, as can cypro-
heptadine (a serotonin antagonist that produces weight
gain), probably through effects on the monoamines (in-
cluding norepinephrine, epinephrine, dopamine, hista-
mine, and serotonin) in the central nervous system.
Eating a high-fat diet and excessive consumption of
sugar-sweetened beverages and the prevalence of abun-
dant varieties of food in cafeterias or supermarkets are
dietary factors in the development of obesity. Reduced
energy expenditure relative to energy intake is another
Due to his enormous size, Frank Williams, age 16, weight 442
major component. Energy expenditure can be divided
pounds, was placed on display at the St. Louis Exposition in
1893. Obese teenagers are now a much more common sight. into four parts.
Photo by McKnight, Paducah, Kentucky, circa 1893. ROUGH- An inactive individual at rest burns between 800 and
WOODCOLLECTION. 900 kilocalories during a twenty-four hour period. This
rate is lower in females than in males, and declines with
age, and could account for much of the increase in fat
stores if food intake does not decline similarly. The ef-
tween ages twenty and fifty, the fat content of males ap- fect of physical exercise on metabolism is variable but on
proximately doubles and that of females increases by average is responsible for about one-third of the daily en-
about 50 percent. Total body weight, however, rises by ergy expenditure. From a therapeutic point of view this
only 10 to 15 percent: fat now accounts for a larger part component of energy expenditure is most easily manip-
of the body weight and lean body mass decreases. ulated. Dietary thermogenesis is the energy expenditure
that follows the ingestion of a meal. Heat produced by
Risks Related to Obesity eating may dissipate up to 10 percent of the ingested calo-
As the BMI increases, there is a curvilinear rise in excess ries. These thermic effects of food are one type of meta-
mortality. This excess mortality rises more rapidly when bolic “inefficiency” in the body, that is, where dietary
the BMI is above 30 kg/m2. A BMI over 40 kg/m2is as- calories are not available for “useful” work. In the obese,
sociated with a further increase in overall risk and for the the thermic effects of food are reduced particularly in in-
risk of sudden death. The principal causes of the excess dividuals with impaired glucose tolerance or diabetes.
mortality associated with overweight include hyperten- Acute over- or underfeeding will produce corresponding
sion, stroke, and other cardiovascular diseases, diabetes
2
ENCYCLOPEDIA OF FOOD AND CULTURE
OBESITY
shifts in overall metabolism, which can be as large as 15 tension, gallbladder disease, and diabetes mellitus associ-
to 20 percent. ated with obesity. They too should be encouraged to use
low-risk treatments, such as caloric restriction and exer-
Genetic factors can produce some types of obesity
cise. Individuals with a BMI of 27 to 30 kg/m2 or more
that are easily recognized. Among these types of obesity
who have diseases related to obesity may use adjunctive
are: (1) the Bardet-Biel syndrome, characterized by reti-
pharmacotherapy for weight loss.
nal degeneration, mental retardation, obesity, polydactyly,
and hypogonadism; (2) the Alstrom syndrome, character- Individuals with a BMI of 30 to 40 kg/m2, have mod-
ized by pigmentary retinopathy, nerve deafness, obesity, erate risk for developing diseases associated with obesity.
and diabetes mellitus; (3) Carpenter syndrome, character- Diet, drugs, and exercise would all appear to be appro-
ized by acrocephaly (abnormalities in the facial and head priate forms of treatment. Individuals with significant de-
bones), mental retardation, hypogonadism, obesity, and grees of excess weight often find exercise difficult.
preaxial syndactyly (extra fingers or toes on one hand or However, exercise is very important in helping to main-
foot); (4) the Cohen syndrome, characterized by mental tain weight loss. The use of weight loss medications, as
retardation, obesity, hypotonia (reduced tone of the mus- an adjunct to treatment, may also be useful in this group.
cles, resulting in a “floppy” muscle mass), and character- Individuals who have a BMI above 40 kg/m2have a high
istic facies (an appearance of the face that is typical of risk of developing diseases associated with their obesity.
specific genetic diseases); (5) the Prader-Willi syndrome, Moderate to severe restriction of calories is the first line
characterized by hypotonia, mental retardation, hypogo- of treatment, but for some of these patients surgery may
nadism, and obesity; and (6) the pro-opiomelanocortin be advisable.
(POMC) syndrome, characterized by defective production
of POMC that is recognized as a red-headed fat child with Treatment of Obesity
a low plasma cortisol (a value that is below the normal Any diet must reduce an individual’s caloric intake below
range). daily caloric expenditure if it is to be successful. This re-
If both parents are obese, about 80 percent of their quires an assessment of caloric requirements, by esti-
offspring will be obese. If only one parent is obese, the mating caloric expenditure from desirable weight tables;
likelihood of obesity in the offspring falls to less than 10 for men, multiply desirable weight by 30 to 35 kilocalo-
percent. Studies with identical twins suggest that inher- ries/kilogram, (14–16 kilocalories/lb.); for women, mul-
itance accounts for about 70 percent and environmental tiply desirable weight by 25 to 30 kilocalories/kilogram
factors (diet, physical inactivity, or both) account for 30 (12–14 kilocalories/lb.). After assessing caloric require-
percent of the variation in body weight. Deficiency of the ments, a reasonable calorie deficit can be prescribed. A
gene leptin and deficiency of the leptin receptor are rare, caloric deficit of 500 kilocalories/day (3,500 kilocalo-
but are associated with massive human obesity. Absence ries/week) will produce the loss of approximately one lb.
of convertase I has also been associated with obesity in (0.45 kilograms) of fat tissue each week. Table 2 gives a
one family. The most common defects associated with list of diets divided into different levels of energy.
massive obesity are abnormalities in the melanocortin re- The very low calorie diet (below 800 kilocalories)
ceptor system—up to 4 percent of massively obese peo- was developed to facilitate the rate of weight loss since
ple may have this type of defect. lower energy intake should lead to greater energy deficit.
In free living people, however, diets with 400 kilocalo-
Evaluation of the Obese Patient ries/day have not produced greater weight loss than those
A medical evaluation should include the expected med- with 800 kilocalories/day, suggesting either that they are
ical history, family history, personal and social history, harder to adhere to or that there is an adaptation in en-
and review of the systems of the body with a particular ergy expenditure. In either case, these diets should only
focus on the medications that can cause weight gain. A be used under appropriate medical supervision.
physical examination should include an assessment of the
patient’s height, weight, waist circumference, blood pres-
sure, and level of health risk due to obesity. Laboratory TABLE 2
tests should include a lipid panel, glucose level, chem-
istry panel for hepatic (liver) function and uric acid, thy- Characterization of diets by composition
roid function testing, and, if indicated a cortisol level.
Carbohydrate Protein
Evaluating Risk Using the Body Mass Index (BMI) Type of diet Calories Fat g (%) g (%) g (%)
Individuals with a normal BMI (20–25 kg/m2) have little Typical American 2,200 85 (35) 274 (50) 82 (15)
or no risk from obesity. Any individual in this weight High-fat, low 1,400 94 (60) 35 (10) 105 (30)
range who wishes to lose weight for cosmetic reasons carbohydrate
Moderate-fat 1,450 40 (25) 218 (60) 54 (15)
should do so only with conservative methods. Individu- Low & very low 1,450 16–24 235–271 54–72
als with a BMI of greater than 25 to 29.9 kg/m2 are in fat (10–15) (65–75) (15–20)
the low-risk group for developing heart disease, hyper-
3
ENCYCLOPEDIA OF FOOD AND CULTURE
OBESITY
creases fiber intake. These diets were developed in a set-
ting designed to reverse the atherosclerotic plaques as-
sociated with risks for heart disease, but because of the
high fiber content they were often associated with weight
loss. Moderate fat levels with higher carbohydrates are
characteristic of many widely recommended “healthy di-
ets.” For weight loss, the New York Health Department
recommends the Prudent Diet, which has stood the test
of time.
The portion-controlled diet makes use of prepared
foods that have a narrow range of calories. This includes
liquid or powdered drinks as well as frozen or canned en-
trees that have about 300 kilocalories/meal. These can be
combined conveniently and thus removes the problem of
counting calories from the individual. A number of pop-
ular diets focus on a single food, and although nutri-
tionally unbalanced, they are simple to follow and the
monotony of single items tends to limit food intake.
Food Guide Pyramid. The Food Guide Pyramid pro-
vides an approach to evaluating the quality of your diet.
At the bottom of the pyramid are the grains, beans, and
starchy vegetables that provide vitamins, minerals, fiber,
and energy; six or more servings are recommended. On
the next level are the vegetables (3–5 servings) and the
fruits (3–4 servings). On the third level are the meats,
fish, poultry, and nuts (2–3 servings) along with the milk
and yogurt (2–3 servings). At the top are the fats, sweets,
Obesity is a highly charged subject that has assumed broad
sociological implications. In this 1998 photographic study and alcohol. Reducing the number of servings propor-
called “Servitude I” by American artist Lynn Bianchi, several tionally will provide you with a calorie-reduced diet.
issues are exposed through novel inversions of female roles: Most important for the dieter, however, is to sharply re-
body image, incessant snacking, and anorexia, to name three. duce the fats and sugar at the top of the pyramid and to
Here it is the overly thin female who acts the role of caryatid- reduce or eliminate alcoholic beverages. Not only do al-
slave to an Earth Mother figure who never stops eating. PHOTO coholic beverages have calories, their consumption tends
COURTESYOFTHEARTISTANDTHERALLSCOLLECTION, INC., WASHINGTON, D.C.
to reduce the individual’s control in selecting the quality
and quantity of foods to eat.
Changing behavioral patterns of eating. The basic
Types of diets. There are several types of diets with more
principles of behavioral approaches for obesity can be
than 800 kilocalories/day that usually have more than
summarized under the ABCs of eating.
1,200 kilocalories/day. They can be divided into several
categories. These categories are based on the relative pro- • The A stands for antecedent. If one looks at eating
portion of macronutrients included in the diet and as the response to events in the environment, then
whether they use special foods. For all diets it must be the antecedent events are those that trigger eating.
true that they reduce the calorie intake to produce a neg- • The B stands for the behavior of eating. This in-
ative energy balance. Low-carbohydrate diets are touted cludes among other things the place, the rate, and
because they produce ketosis (a state of increased ketones the frequency with which an individual eats. If the
associated with diabetes and fasting) and allow you to eat act of eating can be focused at one place with one
all of the protein and fat you want. This ends up reduc- plate and place setting it can help to provide control
ing total calorie intake to about 1,500 kilocalories/day. over eating.
Since these diets generally have carbohydrate levels be-
• The C is the consequence of the eating. The feel-
low 50 g./day they are ketogenic and can be monitored
ings an individual has about eating can be altered,
clinically by the appearance of ketones in the urine. They
and rewards for changing eating patterns can be in-
vary in the level of fiber that is employed. The Atkins diet
stituted.
has low fiber levels, the Sugar Busters diet higher fiber
levels.
Exercise and physical activity. The only part of energy
Low-fat diets recommend fat intake in the range of expenditure that is amenable to significant manipulation
10 to 20 percent of calories. The higher carbohydrate in- is physical activity. During sleep, the lowest level of ac-
4
ENCYCLOPEDIA OF FOOD AND CULTURE
OIL
tivity, approximately 0.8 kilocalories/minute is con- BIBLIOGRAPHY
sumed. Thus, if an individual sleeps for an entire 24 Bessesen, D. H., and R. Kushner. Evaluation and Management
of Obesity. Center for Obesity Research and Education.
hours, approximately 1,150 calories will be expended.
Philadelphia: Hanley and Belfus, 2002.
Reclining increases this level to approximately 1.0-1.4
kilocalories/minute. Obese and diabetic patients should Bray, George A. Contemporary Diagnosis and Management of Obe-
sity.Newtown, Pa.: Handbooks in Health Care, 1998.
be encouraged to increase their physical activity for two
reasons: First, it consumes calories, but second, and more National Heart, Lung, and Blood Institute (NHLBI). Clinical
important, exercise increases glucose utilization and may Guidelines on the Identification, Evaluation, and Treatment of
Overweight and Obesity in Adults.Bethesda, Md., 1998.
improve insulin sensitivity.
Yanovski, J., and S. Z. Yanovski. “Obesity.” New England Jour-
nal of Medicine346, no. 8 (21 February 2002): 591–602.
Drug treatment of obesity. Only a few drugs have been
approved by the Food and Drug Administration for treat- George Bray
ment of obesity. Studies following individuals who have
used these drugs for two years have been published for
sibutramine (Meridia) and orlistat (Xenical). Weight-loss
drugs should be reserved for patients with moderate- or OCTOPUS. See Mollusks.
high-risk obesity (BMI (cid:1) 30 kg/m2) or a BMI above 27
if they have other significant diseases related to obesity.
They should be considered for the patient who has failed
OIL. Oil is liquid fat, usually plant-derived, used as a
to lose weight with other methods. Herbal products con-
cooking medium, as a lubricant to keep food from stick-
taining ephedra and an herbal source of caffeine can also
ing to pans, and as a source of flavor. Oil from animal
produce weight loss when used in accordance with the
sources, particularly fish oil, is also used as a nutritional
package instructions.
supplement. Oil is also ubiquitous in processed foods.
The difference between oil and fat is that oil is liq-
Surgery. Gastric operations reduce the size of or by-
uid at room temperature while fat is solid. Chemically,
pass the stomach, but should be reserved for people with
both are composed of hydrocarbon chains and are potent
a BMI above 40 or when recommended by a physician.
sources of energy. The strong molecular bonds of fats
and oils make them relatively resistant to heat and thus
The Obese Child suitable for high-heat cooking methods such as deep-
Estimates of the prevalence of obesity in children range frying. Oil can be used in conjunction with other fats,
from 3 to 15 percent. This figure has been rising more such as butter, to raise the temperature of the other fat
rapidly than in the rest of the population. The appear- at which it would otherwise begin to break down and
ance of obesity in childhood and particularly adolescence smoke.
is important because it most often persists into adult life.
It may be a precursor to the appearance of type 2 dia- History of Oil
betes in adolescents. The possibility of treatment should Olive oil and sesame oils are among the most ancient oils
be considered for children who are above the seventy- in the Western world, dating back to 4,000 years or more.
fifth percentile of weight for height, and might be en- Olive trees are relatively simple to cultivate and, once the
couraged for those who are above the ninety-fifth olives are prepared, the oil can be obtained by pressing.
percentile of weight for height. The treatment of prepu- Both olive oil and sesame oil were used in southern Eu-
bertal children should probably involve both parents and rope, while northern countries typically used animal fats
child since at this age the principal control of food avail- such as lard or goose fat.
ability is in the hands of the parents. For adolescents,
In the Orient, oil was pressed from soybeans, while
however, it may be better to separate patient and parents,
sesame, mustard seed, and safflower oils were used in In-
since the interaction between these groups may be part
dia and ancient Egypt. Peanuts, corn, and sunflower seeds
of the problem. Where growth has not reached its fullest
were available in the New World, but oil was generally
extent, dietary restriction should attempt to reduce fur-
extracted only from squash seeds, especially squash be-
ther weight gain. Severe caloric restriction and the use
longing to the species Cucurbita pepo.
of appetite-suppressing drugs may slow height growth.
The nineteenth century saw the rise of international
For both children and adolescents, involvement in a reg-
trade in tropical oils, particularly palm and coconut oil.
ular exercise program is probably the first line of treat-
The raw materials, which included hearts of palm and
ment.
dried coconut meat (copra), were exported from Africa
and the Pacific islands to industrial countries to be
See alsoAnorexia, Bulimia; Body; Body Composition;
Caloric Intake; Eating: Anatomy and Physiology of pressed for oil. The vast production of corn in the United
Eating; Fasting and Abstinence; Fats; Fiber, Dietary; States provided a source of oil to be used in cooking and
Hunger, Physiology of. in the manufacture of oleomargarine.
5
ENCYCLOPEDIA OF FOOD AND CULTURE
OIL
(LDL) associated with cholesterol. HDL (the “good cho-
lesterol”) is a beneficial substance that helps the body get
rid of excess cholesterol, while LDL (the “bad choles-
terol”) builds up in the arteries and can increase the risk
of heart disease. Eating foods high in monounsaturated
fatty acids is believed to help lower LDL cholesterol lev-
els and decrease the risk of heart disease, while the con-
sumption of saturated fats may increase levels of LDL
and total cholesterol. The consumption of polyunsatu-
rated fats in place of saturated fats decreases LDL
cholesterol levels. The American Heart Association rec-
ommends the consumption of oils that have no more than
two grams of saturated fat per tablespoon.
Unsaturated fat content is a major selling point for
household oils. One of the major oils on the market,
Olive oil is one of the major culinary oils employed in the
Mediterranean region. This home-pressed oil is being bottled canola oil, was developed specifically to appeal to con-
for private use at Dolcedo, Italy. © OWENFRANKEN/CORBIS. sumers concerned about fat content. Canola—short for
“Canadian oil”—is a variety of the rapeseed plant devel-
oped in Canada with less fatty acid than the traditional
In nineteenth-century Africa, both the French and variety and thus a lower level of saturated fat than most
British introduced larger-scale peanut farming specifi- other oils.
cally for peanut oil, which was used as an adulterant in The chemical structure of oils makes them relatively
cheap grades of olive oil, and as a base ingredient in soap. stable at high temperatures, but at some point oil begins
to break down and give off smoke; beyond this point there
is danger of fire. The smoke point for most oils is around
Composition of Oils
410°F (210ºC), although some oils have even higher
Oils, like other fats, consist mostly of triglycerides, which
smoke points. The smoke point gets lower as oil is re-
are three fatty acids attached to a molecule of glycerol
used due to degradation of chemical bonds and contam-
(an alcohol built around three atoms of carbon). A fatty
ination of the oil with food particles. Commercial
acid consists of a carboxyl group (carbon, oxygen, and
operations that re-use oil will pass it through a filter to
hydrogen linked together), which in turn is linked to a
take out the contaminants.
hydrocarbon chain. The more the hydrocarbon chain is
filled with hydrogen atoms, the more chemically stable Sources of Oil
it will be. A fatty acid fully loaded with hydrogen is said In addition to olives, oil is obtained from legumes such
to be “saturated,” while a less hydrogen-rich acid is as peanuts and soybeans; from the seeds of many plants,
“monounsaturated” or “polyunsaturated,” depending on including corn, rapeseed (canola), sesame, cottonseed,
its structure. Oleic acid is a common monounsaturated sunflower, palm, safflower, coconut, grapeseed, mustard,
fat, while linoleic acid is the most common polyunsatu- pumpkin, and avocado; and from tree nuts such as wal-
rated fatty acid.
The more saturated a fat is, the more likely it is to TABLE 1
be solid at room temperature (such as lard or shorten-
ing). Oils are liquid because they are less saturated than
Smoke Points of Common Oils
fats. They are also less shelf-stable because their chemi-
cal structures are more likely to be affected by exposure
to oxygen, causing them to become rancid or develop off- Oil Smoke point (degrees F)
flavors. To make the product more stable, food proces-
Sunflower 392
sors pump hydrogen through the oil to fill in the gaps in
Olive 410
its chemical structure, a process known as “hydrogena-
Corn 410
tion.” Highly hydrogenated oil is creamy or solid at room
Peanut 410
temperature, useful for making oleomargarine or other
Soybean 410
processed food products. Cottonseed 435
Avocado 435
Oils generally have about the same caloric value of
Canola 437
approximately 120 calories per tablespoon whether the
Grapeseed 446
fatty acids are saturated or not. More important to health-
conscious consumers is the role of fatty acids in raising SOURCE: The Simon and Schuster Pocket Guide to Oils, Vinegars,
or lowering the presence in the bloodstream of the high- and Seasonings
density lipoprotein (HDL) or low-density lipoprotein
6
ENCYCLOPEDIA OF FOOD AND CULTURE
OIL
TABLE 2
Fat Content of Major Household Oils
Saturated
fatty acids Polyunsaturated Monounsaturated
Calories per (grams per fatty acids (grams fatty acids (grams per
Oil tablespoon tablespoon) per tablespoon tablespoon)
Olive 119.3 1.8 1.1 9.9
Corn 120.2 1.7 8.0 3.3
Canola 123.8 1.0 4.1 8.2
Peanut 119.3 2.3 4.3 6.2
Sesame 120.2 1.9 5.7 5.4
Soybean 120.2 2.0 8.0 3.2
Soybean, hydrogenated 120.2 2.0 5.1 5.8
Sunflower, 70% oleic and over 123.8 1.4 0.5 11.7
Sunflower, less than 60% linoleic 120.2 1.4 5.5 5.5
Sunflower, 60% linoleic and over 120.2 1.4 8.9 2.6
Sunflower, linoleic, hydrogenated 120.2 1.8 4.9 6.3
Grapeseed 120.2 1.3 9.5 2.2
Cottonseed 120.2 3.5 7.1 2.4
Safflower, over 70% linoleic 120.2 0.8 10.1 1.9
Almond 120.2 1.1 2.4 9.5
Rice bran 120.2 2.7 4.8 5.3
Avocado 123.8 1.6 1.9 9.9
Palm 120.2 6.7 1.3 5.0
Fish oil, menhaden, fully hydrogenated * 112.7 11.9 0.00 0.00
Unlike oils from plant sources, fish oil contains cholesterol. Fully hydrogenated menhaden oil contains 62.5 milligrams of cholesterol per tablespoon.
SOURCE: U.S. Department of Agriculture, Agricultural Research Service. 2001. USDA Nutrient Database for Standard Reference, Release 14.
Nutrient Data Laboratory Home Page, http://www.nal.usda.gov/fnic/foodcomp.
nuts, almonds, hazelnuts, and pistachios. Tree nut oils hot oil, just enough to keep the food from sticking to the
are usually expensive and do not respond well to high pan. Chicken can be sautéed or fricasseed in a few table-
heat, so they are used primarily to dress salads or to add spoons of oil, while pieces of breaded fish can be fried in
flavor to baked goods. shallow oil—perhaps a quarter of an inch deep.
The finest oils are simply extracted from the raw ma- Frying large pieces of food in deep oil requires a tem-
terial (such as olives or nuts) by pressure. This is called perature of 350°to 375°F (177°to 191°C). At that tem-
“cold pressed” or “first pressed” oil. Oil that remains perature, the hot oil will sear the surface of the food being
bound up in the raw material can be extracted by heat or fried, trapping moisture within the food. The food thus
chemical solvents. cooks in its own moisture rather than in the oil, which is
why properly fried food is not greasy. Greasiness results
Oils labeled by specific names, such as peanut oil,
from frying at a temperature lower than optimal.
are obtained from those particular plants; a product la-
beled merely “vegetable oil” is a blend of various oils. In In Italy, olive oil is used as a dipping sauce for bread
the production of vegetable oils, seeds are cracked, at the table. Olive oil is preferred as a salad dressing be-
cooked, and run through a press to extract readily ob- cause it has its own flavor to contribute to the dish.
tainable oil. The pulp is further processed to obtain the In food manufacturing, oils are used in a host of
rest of the oil, which is neutral and tasteless; if flavor is products, ranging from soups and gravies, salad dressings,
desired, the oil can be mixed with the product of the first bread and rolls, and fried foods to nondairy toppings and
pressing to restore flavor and color. frozen desserts, coffee creamers and cocoa mixes, candy
bars and cakes, and in most processed snack foods.
Uses of Oil
Oil has a variety of uses in cooking, most of them based Fish Oil
on its ability to transfer heat to the food while remain- Some species of fish such as Atlantic menhaden have high
ing stable itself. Asian food is often stir-fried in a little levels of certain essential fatty acids, called omega-3 fatty
7
ENCYCLOPEDIA OF FOOD AND CULTURE
ONIONS AND OTHER ALLIUM PLANTS
acids, which the human body is not able to synthesize by TABLE 1
itself and must obtain from food. Oil made from these fish
is sold as a nutritional supplement. Menhaden oil is used
The seven primary edible allium crop complexes
in the production of margarine and shortening in Europe
and has been approved for use in the United States.
Species Complex Crop Variety Storage Organs
See alsoButter; Cooking; Fats; Fish; Frying; Snacks.
cepa bulb onion cepa foliage leaf bases
shallot ascolonicum and bladeless
leaf sheaths
BIBLIOGRAPHY fistulosum bunching NA foliage leaf bases,
Lane, Mark, and Judy Ridgway. The Simon and Schuster Pocket onion bulbs absent
Guide to Oil, Vinegars, and Seasonings. New York: Simon schoenoprasum chives NA foliage leaf bases,
bulbs absent
and Schuster, 1990.
tuberosum Chinese NA rhizomes, bulbs
McGee, Harold. On Food and Cooking: The Science and Lore of chives absent
the Kitchen. New York: Fireside Books, 1984. ampeloprasum leek porrum bulbs generally
kurrat kurrat absent, cloves
Pehaut, Yves. “The Invasion of Foreign Foods.” In Food: A Culi- great-headed holmense like garlic in
nary History from Antiquity to Present,edited by Jean-Loius garlic sectivum great-headed
Flandrin and Massimo Montanari, pp. 457–463. New York: pearl onion garlic and pearl
onion;
Penguin Books, 1999.
pseudostem in
Tannahill, Reay. Food in History.New York: Three Rivers Press, leek and kurrat
1988. sativum garlic sativum swollen, bladeless
sheaths (cloves)
Richard L. Lobb chinense rakkyo NA swollen, foliage
leaf bases, bulbs
prominent
NA = not applicable
SOURCE: Brewster, 1994, as redrawn from Jones and Mann, 1963
ONIONS AND OTHER ALLIUMPLANTS. Al-
lium crops have been cultivated for millennia by people
worldwide for sustenance, flavor, and medicinal purposes.
Each of these three properties is closely connected to a Taxonomic History
suite of unique organosulfur compounds present in Al- The genus Allium contains more than five hundred
lium crops that make them distinct from other wild and species, including many ornamental and edible plants.
cultivated food plants. These compounds impart the The genus has been assigned to the family Alliaceae, al-
characteristic flavors and odors of edible alliums. A sub- though for many years it was classified with both the
stantial body of scientific literature suggests that these Amarylidaceae and the Liliaceae. Edible alliums are im-
organosulfur compounds likely arose through natural se- portant staples in the diets of many of the world’s cul-
lection for pest resistance. In a fortuitous circumstance, tures. Most of the edible alliums are native to the
humans find these odors and flavors appealing, thus what mountains of central Asia, and a number of alliums are
confers functional significance to the Allium crop for its still collected from the wild in this region. Distribution
survival also confers culinary significance to the Allium of Allium crops ranges widely throughout the Northern
consumer for gastronomic pleasure. Hemisphere and in mountainous regions of the tropics.
The area of greatest diversity is the mountains of central
Seven major allium crop complexes are recognized,
Asia, including Afghanistan, Tajikistan, Pakistan, and
five of which contain a single allium crop (Table 1). These
parts of Siberia and China.
five are bunching onion (fistulosum), chives (schoenopra-
sum), Chinese chives (tuberosum), garlic (sativum), and Many edible alliums are classified into two subgen-
rakkyo (chinense). The remaining two complexes contain era, Rhizirideumand Allium.In subgenus Rhizirideumthe
four separate crops (leek, kurrat, great-headed garlic, and sections Cepa, Schoenoprasum, and Rhizirideum are
pearl onion) in the case of ampeloprasum and two differ- comprised of the species cepa, fistulosum, schoenoprasum,
ent crops (onion and shallot) in the case of cepa. Each of andtuberosum. In the subgenus Alliumthe section Allium
these crops represents a unique modification of the leaf. is comprised of the species ampeloprasum, sativum, and
In the allium crops where bulbs are prominent, leaf bases chinense (Hanelt, 1990; Brewster, 1994). Together these
are swollen due to the accumulation of carbohydrates seven species contain the primary edible alliums con-
from photosynthesis. In those crops where pseudostems sumed throughout the world. G. R. Fenwick and A. B.
are the edible portion, overlapping leaf bases form a hol- Hanley (1985) also describe a number of other minor al-
low column that has the appearance of a stem, such as liums consumed as vegetables or herbs, including the
the base of the leek. For other allium crops the edible topset onion, the tree onion, the Wakegi onion, and oth-
portion is the leaf blade, which also serves as the primary ers. These minor alliums are primarily from the Allium
photosynthetic organ. These seven crop complexes are cepa group and are discussed in some detail in Henry A.
grown and consumed worldwide for a multiplicity of uses. Jones and LouisK. Mann’s Onions and Their Allies(1963).
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ENCYCLOPEDIA OF FOOD AND CULTURE