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Chapter 1

  Introduction

 

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Nutritional science investigates the metabolic andphysiological responses of the body to dietand body nutrients requirements

the study of nutrition is increasinglyconcerned with metabolism and metabolic

pathways :the sequences of biochemicalsteps through which substances in livingthings change from one form to another 

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A nutrient is a chemical that an organism needs to live and grow or a substanceused in an organism's metabolism which

must be taken in from its environment.Nutrients are the substances that enrichthe body. They build and repair tissues,give heat and energy, and regulate body

processes 

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Body building depends on type of nutrients ingestion, digestion,absorption and their circulation in

blood stream to feed cells of body.And so our foods life styles effectdramatically on our body health

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Studies of nutritional status

Food input composition

Metabolism processes body intake= food inputs-o outputs( urine+ composition)

Outputs: urine and waste

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Some people are worried about the effectof food processing on nutritional valuelike canning, freezing, dehydration, and

fortifying

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Factors contributing to poor nutrition

income

lack of education

• Some bad behaviors in nutrition:

1- less intake of deep green and yellow vegetables,vit c rich fruit, and whole grain bread and cereals

2- fats and sugars contribute as much as 30% of calories

3- breakfast is often skipped4- high calorie food and low nutrient lunch

5- snacks are too frequently made up of highcalorie, low nutrients density

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Chapter two

Nutrients

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2.Nutrients 

There are seven major classes of nutrients:

Carbohydrates

Fats

fibers

Proteins

Minerals

Vitamins

water

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Nutrients classified into:

Macronutrients ( needed in largequantities) like: carbohydrates,water, fibers, and fats.

Micronutrients ( needed in smallquantities) like: vitamins andminerals

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The macronutrients (excluding fiber and water)provide structural material (amino acids from

which proteins are built, and lipids from which cellmembranes and some signaling molecules arebuilt), energy.

Some of the structural material can be used togenerate energy internally, and in either case it ismeasured in Joules or kilocalories (often called"Calories" and written with a capital C todistinguish them from little 'c' calories).

Carbohydrates and proteins provide 17 kJapproximately (4 kcal) of energy per gram, while

fats provide 37 kJ (9 kcal) per gram 

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Vitamins, minerals, fiber, and water do not provideenergy, but are required for other reasons.

Most foods contain a mix of some or all of thenutrient classes, together with other substancessuch as toxins or various sorts. Some nutrients can

be stored internally (eg, the fat soluble vitamins),while others are required more or less continuously.Poor health can be caused by a lack of requirednutrients or, in extreme cases, too much of a

required nutrient. For example, both salt and water(both absolutely required) with cause illness oreven death in too large amounts

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Requirement  

Minimum amount of a nutrient needed

to sustain a physiological state,function, or structure in an individual

Recommendation 

Normalized estimate of nutrientneeded to cover most individuals in a

population group

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RDA - Recommended Dietary Allowanceof nutritional elements

RDA, or known by its full name -Recommended Daily Allowance - is busybeing revised and will be called the

Dietary Reference Intake (DRI) and is acollaborative effort between the USA andCanada

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The RDA represents the establishment of anutritional form for planning and assessingdietary intake, and are the levels of intake

of essential nutrients considered to beadequate to meet the known needs of practically all healthy people.

These figures were first published in 1943

and have been updated and expanded asdata became available

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Estimated Average Requirement(EAR):

The average daily nutrient intake level

estimated to meet the requirements of half of the healthy individuals in a group

classified by age and gender.

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Recommended Dietary Allowance(RDA):

An average daily dietary nutrient intake

level that is estimated to meet thenutrient requirements of most (97% to98%) healthy individuals in a groupclassified by age and gender.

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Adequate Intake (AI):

A recommended average daily intake levelbased on observed or experimentallydetermined approximations or estimates

of nutrient intake by a group (or groups)of apparently healthy people who areassumed to be maintaining adequatenutrition. The AI is used when an RDA

cannot be determined.

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Acceptable Macronutrient Distribution

Ranges (AMDR): An estimate of the range of intakes of an

energy source associated with a reduced

risk of chronic disease and adequateamounts of essential nutrients. AMDR isexpressed as a percentage of total energyintake, with lower and upper boundaries:

Carbohydrate: 35% to 55% of caloriesFat: 20% to 35% of calories

Protein: 15% to 35% of calories

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Fat Soluble Vitamins

Age Energy  Protein  Vitamin A  Vitamin D  Vitamin E  Vitamin K k. cal  g  IU  *ug

RE  IU  *ug  IU  *mg

TE  *ug Children  4-6  1,800  30/24  2,50

0  500  400  5  9  7  -/20 7-10  2,400/

2,000  36/28  3,30

0  500  400  5  10  7  -/30 Males  15-18  3,000  54/59  5,00

0 

1,00

0  400  5  15  10  -/65 

19-24  3,000/

2,900  54/58  5,00

0 1,00

0  400  5  15  10  -/70 25-50  2,700  56/63  5,00

0 1,00

0  -  5  15  10  -/80 50+  2,400  56/63  5,00

0 1,00

0  -  10  15  10  -/80 Females  15-18  2,100  48/44  4,00

0  800  400  5  12  8  -/55 19-24  2,100  46/46  4,00

0  800  400  5  12  8  -/60 25-50  2,000  46/50  4,00

0  800  -  5  12  8  -/65 50+  1,800  46/50  4,00

0  800  -  10  12  8  -/65 

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Water Soluble Vitamins

Age Ascorbic

Acid Folacin/

Folate  Niacin  Riboflavi

n  Thiamine Vitamin

B6 Vitamin

B12 mg  mcg  mg  mg  mg  mg  mcg 

Children  4-6  40/45  200/75  12  1.1  0.9  0.9/1.1  1.5/1.0 7-10  40/45  300/100  16/13  1.2  1.2/1.0  1.2  2.0/1.4 

Males  15-18  45/60  400/200  20  1.8  1.5  2.0  3.0/2.0 19-24  45/60  400/200  20/19  1.8/1.7  1.5  2.0  3.0/2.0 25-50  45/60  400/200  18/19  1.6/1.7  1.4/1.5  2.0  3.0/2.0 50+  45/60  400/200  16/15  1.5/1.4  1.2  2.0  3.0/2.0 

Females  15-18  45/60  400/180  14/15  1.4/1.3  1.1  2.0/1.5  3.0/2.0 19-24  45/60  400/180  14/15  1.4/1.3  1.1  2.0/1.6  3.0/2.0 25-50  45/60  400/180  13/15  1.2/1.3  1.0/1.1  2.0/1.6  3.0/2.0 50+  45/60  400/180  12/13  1.1/1.2  1.0  2.0/1.6  3.0/2.0 

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Minerals and others

  Age  Calcium  Phospho

rous  Iodine  Iron  Magnesi

um  Zinc  Seleniu

m  Fluoride mg  mg  ug  mg  mg  mg  *ug  *mg 

Children  4-6  800  800/500  80/90  10  200/130  10  -/20  -/1.1 7-10  800  800  110/120  10  250  10  -/30  -/3.2 

Males  15-18  1200/130

0 1200/125

0 150  18/12  400/410  15  -/50  -/3.8 

19-24  800/1000 800/700  140/150  10  350/400  15  -/70  -/3.8 25-50  800/1000 800/700  130/150  10  350/420  15  -/70  -/3.8 50+  800/1200 800/700  110/150  10  350/420  15  -/70  -/2.9 

Females  15-18  1200/130

0 1200/125

0  115/150  18/15  300/360  15/12  -/50  -/3.1 19-24  800/1000 800/700  100/150  18/15  300/310  15/12  -/55  -/3.1 25-50  800/1000 800/700  100/150  18/15  300/320  15/12  -/55  -/3.1 50+  800/1200 800/700  80/150  10  300/320  15/12  -/55  -/3.1 

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Chapter 3 

•Carbohydrates

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Carbohydrates or saccharides are the mostabundant of the four major classes of biomolecules. They fill numerous roles in livingthings, such as the storage and transport of energy (e.g., starch, glycogen) and structural

components (e.g., cellulose in plants). Inaddition, carbohydrates and their derivatives playmajor roles in the working process of the immunesystem, fertilization, pathogenesis, blood clotting,and development.

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Carbohydrates are simple organic compounds that are aldehydes or ketones with manyhydroxyl groups added, usually one on eachcarbon atom that is not part of the aldehyde or

ketone functional group.

For example, deoxyribose, a component of DNA,is a modified version of ribose; chitin is

composed of repeating units of N-acetylglucosamine, a nitrogen-containing form of 

glucose. 

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Use in living organisms 

Monosaccharides are the major source of fuel formetabolism, being used both as an energy source(glucose being the most important in nature) andin biosynthesis. When monosaccharides are not

immediately needed by many cells they are oftenconverted to more space efficient forms, oftenpolysaccharides. In many animals, includinghumans, this storage form is glycogen, especially

in liver and muscle cells. In plants, starch is usedfor the same purpose.

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Carbohydrates are not essential nutrients inhumans: the body can obtain all its energy fromprotein and fats. However, the brain and neuronsgenerally cannot burn fat and need glucose for

energy; the body can make some glucose from afew of the amino acids in protein and also from

the glycerol backbone in triglycerides 

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Based on the effects on risk of heart disease andobesity, the Institute of Medicine recommendsthat American and Canadian adults get between40-65% of dietary energy from carbohydrates.The Food and Agriculture Organization and World

Health Organization jointly recommend thatnational dietary guidelines set a goal of 55-75%of total energy from carbohydrates, but only 10%directly from sugars (their term for simplecarbohydrates).

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Carbohydrate Catabolism 

Catabolism is the metabolic reaction cellsundergo in order to extract energy. Thereare two major metabolic pathways of 

monosaccharide catabolism:Glycolysis 

Citric acid cycle 

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Glycolysis cycle

 

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Carbohydrates may be classified asmonosaccharides, disaccharides, or

polysaccharides depending on thenumber of monomer (sugar) unitsthey contain. They constitute a largepart of foods such as rice, noodles,bread,potato, beans and other grain-based products.

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Complex sugars take long time indigestion and absorption while Simplecarbohydrates are absorbed quickly, and

therefore raise blood-sugar levels morerapidly than other nutrients 

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However, the most important plant carbohydratenutrient, starch, varies in its absorption.Gelatinized starch (starch heated for a fewminutes in the presence of water) is far more

digestible than plain starch. And starch which hasbeen divided into fine particles is also more

absorbable during digestion. 

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2.3 Fiber 

Dietary fiber (fibre), sometimes calledroughage, is the indigestible portion of plantfoods that pushes food through the digestivesystem, absorbing water and easing defecation 

Chemically, dietary fiber consists of non-starch polysaccharides such as cellulose and many otherplant components such as dextrins, inulin, lignin,waxes, chitins, pectins, beta-glucans and

oligosaccharides. The term "fiber" is somewhat of a misnomer, since many types of so-called

dietary fiber are not fibers at all 

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Dietary fiber can be soluble (able to dissolve inwater) or insoluble (not able to dissolve inwater). Soluble fiber, like all fiber, cannot bedigested. But it does change as it passes through

the digestive tract, being transformed(fermented) by bacteria there. Soluble fiber alsoabsorbs water to become a gelatinous substancethat passes through the body. Insoluble fiber,

however, passes through the body largelyunchanged 

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both types of fiber are present in all plantfoods, with varying degrees of eachaccording to a plant’s characteristics.

Potential advantages of consuming fiberare the production of health-promotingcompounds during the fermentation of soluble fiber, and insoluble fiber's ability

(via its passive water-attractingproperties) to increase bulk, soften stooland shorten transit time through theintestinal tract 

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Sources of fiber 

All plants contains fibers.

Fiber-rich plants can be eaten directly. Or,

alternatively, they can be used to makesupplements and fiber-rich processedfoods.

The American Dietetic Association (ADA)recommends consuming a variety of fiber-rich foods.

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Plant sources of fiber 

Some plants contain significant amounts of soluble and insoluble fiber. For example plums (or prunes) have a thick skin covering a juicypulp. The plum's skin is an example of an

insoluble fiber source, whereas soluble fibersources are inside the pulp 

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Soluble fiber is found in varying quantities inall plant foods, including:

legumes (peas, soybeans, and other beans)

oats, rye , and barley 

some fruits and fruit juices (including prune juice,plums, berries, bananas, and the insides of 

apples and pears)certain vegetables such as broccoli, carrots andJerusalem artichokes 

root vegetables such as potatoes, sweet

potatoes, and onions (skins of these vegetablesare sources of insoluble fiber)

psyllium seed husk (a mucilage soluble fiber).

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Sources of insoluble fiber include: 

whole grain foods

wheat and corn bran 

nuts and seeds 

potato skinsflax seed 

vegetables such as green beans,cauliflower  , zucchini (courgette),

celery  the skins of some fruits, includingtomatoes 

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Quinoa

 

Rubus

The five most fiber-rich plantfoods, according to theMicronutrient Center of the Linus

Pauling Institute, are legumes (15-19 grams of fiber per US cupserving, including several types of beans, lentils and peas), wheatbran (17 grams per cup), prunes (12 grams), Asian pear (10 gramseach, 3.6% by weight), andquinoa (9 grams).

Rubus fruits such as raspberry (8grams of f iber per serving) andblackberry (7.4 grams of fiber perserving) are exceptional sources of fiber 

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Fiber supplements 

gastrointestinal disorders

lowering cholesterol levels

reducing risk of colon cancer,

losing weight.

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alleviating symptoms of irritable bowel syndrome,such as diarrhea and/or constipation andabdominal discomfort.

Prebiotic soluble fiber products, like thosecontaining inulin or oligosaccharides, maycontribute to relief from inflammatory boweldisease, as in Crohn's disease, ulcerative colitis,

and Clostridium difficile, due in part to the short-chain fatty acids produced with subsequent anti-

inflammatory actions upon the bowel. 

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Inulins 

Inulins are a group of naturally occurringpolysaccharides (several simple sugars linkedtogether) produced by many types of plants.They belong to a class of fibers known as

fructans. Inulin is used by some plants as ameans of storing energy and is typically found inroots or rhizomes. Most plants that synthesizeand store inulin do not store other materials such

as starch.

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Uses in food processing

inulins flavour ranges from bland to subtly sweet(approx. 10% sweetness of sugar/sucrose). Itcan be used to replace sugar, fat, and flour.

inulin energy= ½-1/3 of sugars = 1/9-1/6 fat

While inulin is a versatile ingredient, it also hashealth benefits. Inulin increases calcium 

absorption and possibly magnesium absorption,while promoting the growth of intestinal bacteria.

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Nutritionally, it is considered a form of solublefiber and is sometimes categorized as a prebiotic.Inulin has a minimal impact on blood sugar,and—unlike fructose—is not insulemic and does

not raise triglycerides, making it generallyconsidered suitable for diabetics and potentially

helpful in managing blood sugar-related illnesses. 

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side effect 

The consumption of large quantities (particularlyby sensitive or unaccustomed individuals) canlead to gas and bloating, and products whichcontain inulin will sometimes include a warning to

add it gradually to one's diet. 

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Industrial use 

Nonhydrolyzed inulin can also be directlyconverted to ethanol in a simultaneoussaccharification and fermentation process whichmay have great potential for converting crops

high in inulin into ethanol for fuel 

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Medical

Inulin is used to help measure kidney function bydetermining the glomerular filtration rate (GFR ).GFR is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's

capsule per unit time 

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Health effects 

Inulin is indigestible by the human enzymes ptyalin and amylase, which are adapted to digeststarch. As a result, inulin passes through much of  the digestive system intact. It is only in the colon that bacteria metabolise inulin, with the release

of significant quantities of carbon dioxide,hydrogen, and/or methane. Inulin-containingfoods can be rather gassy, particularly for thoseunaccustomed to inulin, and these foods shouldbe consumed in moderation at first.

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Insoluble fiber increases the movement of materials through the digestive system andincreases stool bulk; it is especially helpful forthose suffering from constipation or stool

irregularity.

Soluble fiber dissolves in water to form agelatinous material. Some soluble fibres may

help lower blood cholesterol and glucose levels.

Inulin is considered a soluble fiber. 

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Inulin also stimulates the growth of bacteria inthe gut. Inulin passes through the stomach andduodenum undigested and is highly available tothe gut bacterial flora. This makes it similar to

resistant starches and other fermentablecarbohydrates. This contrasts with proprietaryprobiotic formulations based on lactic acidbacteria (LAB) in which the bacteria have to

survive very challenging conditions through thegastrointestinal tract before they are able to

colonize the gut 

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Inulin is generally recognized as safe (GRAS) bythe U.S. Food and Drug Administration (FDA)

There is a single report of what is claimed to bean allergic reaction to inulin in the literature :every day billions of people eat inulin-containingfoods, e.g. onions, without any suggestion of allergy.

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About 30 –40% of people in Central Europe suffer

from fructose malabsorption. Since inulin is afructan, excess dietary intake may lead to minorside effects such as increased flatulence and

loosened bowel motions in those with fructosemalabsorption. It is recommended that fructanintake for people with fructose malabsorption be

kept to less than 0.5 grams/serving. 

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Natural sources of inulin Elecampane (Inula helenium) Dandelion (Taraxacum officinale)

Wild Yam (Dioscorea spp.)Jerusalem artichokes (Helianthus tuberosus) Chicory (Cichorium intybus)

Jicama (Pachyrhizus erosus)

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Burdock ( Arctium lappa)

Onion ( Allium cepa) , Garlic ( Allium sativum)Agave ( Agave spp.) Yacón (Smallanthussonchifolius spp.)

Camas (Camassia spp.)

Benefits of fiber intake

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BenefitsFunctions

May reduce appetiteAdds bulk to your diet, making youfeel full faster

Lowers variance in blood sugarlevels

Attracts water and turns to gel duringdigestion, trapping carbohydrates and

slowing absorption of glucose

Reduces risk of heart diseaseLowers total and LDL cholesterol

May reduce onset risk orsymptoms of metabolic syndromeand diabetes

Regulates blood sugar

May reduce risk of colorectalcancer

Balance intestinal pH and stimulatesintestinal fermentation production of short-chain fatty acids

Facilitates regularitySpeed the passage of foods throughthe digestive system

Alleviates constipationAdds bulk to the stool

bothsolubleinsoluble

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Guidelines on fiber intake 

Current recommendations from the United StatesNational Academy of Sciences, Institute of Medicine, suggest that adults should consume20-35 grams of dietary fiber per day, but theaverage American's daily intake of dietary fiber is

only 12-18 grams

The ADA recommends a minimum of 20-35 g/dayfor a healthy adult depending on calorie intake(e.g., a 2000 cal/8400 kJ diet should include 25 g

of fiber per day). The ADA's recommendation forchildren is that intake should equal age in yearsplus 5 g/day (e.g., a 4 year old should consume9 g/day). 

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In clinical trials to date, these fiber sources wereshown to significantly reduce blood cholesterollevels, an important factor for generalcardiovascular health, and to lower risk of onset

for some types of cancer 

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Soluble (fermentable) fiber sources gaining FDAapproval are:

Psyllium seed husk (7 grams per day)

Beta-glucan from oat bran, whole oats, oatrim orrolled oats (3 grams per day)

Beta-glucan from whole grain or dry-milled

barley (3 grams per day) 

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Other examples of fermentable fiber sources(from plant foods or biotechnology) used infunctional foods and supplements include inulin,resistant dextrins, fructans, xanthan gum,

cellulose, guar gum, fructooligosaccharides (FOS)and oligo- or polysaccharides.

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Consistent intake of fermentable fiber throughfoods like berries and other fresh fruit,vegetables, whole grains, seeds and nuts is nowknown to reduce risk of some of the world’s mostprevalent diseases— obesity, diabetes, high bloodcholesterol, cardiovascular disease, andnumerous gastrointestinal disorders. In this lastcategory are constipation, inflammatory boweldisease, ulcerative colitis, hemorrhoids, Crohn’sdisease, diverticulitis, and colon cancer — alldisorders of the intestinal tract wherefermentable fiber can provide healthful benefits

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Insufficient fiber in the diet can complicatedefecation. Low-fiber feces are dehydrated andhardened, making them difficult to evacuate — defining constipation and possibly leading to

development of hemorrhoids or anal fissures.

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Fiber and calories 

Calories or kilojoules (as used on nutrition labels)are intended to be a measure of how muchenergy is available from the food source. Thisenergy can be used immediately, for example

allowing the body to move during exercise, or tomake the heart beat. Energy that is not usedimmediately is stored as sugars in the short termand later converted to fats, which act as energyreserves.

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Energy is extracted from food in a chemicalreaction. Because of the principle of conservationof energy, energy can only be extracted when thechemical structure of food particles is changed.

Since insoluble fiber particles do not changeinside the body , the body should not absorb any

energy (or Calories/kilojoules) from them 

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FDA-approved health claims 

The FDA allows producers of foodscontaining 1.7 g per serving of psylliumhusk soluble fiber or 0.75 g of oat or

barley soluble fiber as beta-glucans toclaim that reduced risk of heart disease 

can result from their regular consumption 

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As discussed in FDA regulation 21 CFR 101.81, thedaily dietary intake levels of soluble fiber fromsources listed above associated with reduced riskof coronary heart disease are:

3 g or more per day of beta-glucan soluble fiberfrom either whole oats or barley, or acombination of whole oats and barley

7 g or more per day of soluble fiber from psylliumseed husk

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Soluble fiber fermentation 

The American Association of Cereal Chemists hasdefined soluble fiber this way: “  the edible parts of  plants or similar carbohydrates resistant todigestion and absorption in the human small 

intestine with complete or partial fermentation inthe large intestine 

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As an example of fermentation, shorter-chaincarbohydrates (a type of fiber found in legumes)cannot be digested, but are changed viafermentation in the colon into short-chain fatty

acids and gases (which are typically expelled asflatulence 

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According to a 2002 journal article, fibers compoundswith partial or low fermentability include:

cellulose, a polysaccharide 

hemicellulose, a polysaccharide

lignans, a group of phytoestrogens 

plant waxes 

resistant starches 

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Fiber compounds with high fermentability include:

beta-glucans, a group of polysaccharides

pectins, a group of heteropolysaccharides 

natural gums, a group of polysaccharides

inulins, a group of polysaccharides

oligosaccharides, a group of short-chained or

simple sugars resistant dextrins 

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Misconceptions

Fiber does not bind to minerals and vitamins andtherefore does not restrict their absorption, butrather evidence exists that fermentable fibersources improve absorption of minerals,

especially calcium. Some plant foods can reducethe absorption of minerals and vitamins likecalcium, zinc, vitamin C and magnesium, but thisis caused by the presence of phytate (which isalso thought to have important health benefits),

not by fiber 

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Chapter 4

Fat

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There is about 100 million tons of lipids produced per year through theworld

Average consumption per person was15kg in 1993 and raise to 17.2 kg in1995

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Fats consist of a wide group of compounds that are generally soluble inorganic solvents and largely insoluble inwater. Chemically, fats are generally

triesters of glycerol and fatty acids 

Example of an unsaturated fat triglyceride Left part:

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Example of an unsaturated fat triglyceride. Left part:

oleic,acidpalmitic, right part from top to bottom:glycerol

 6O98H55, chemical formula: Cacidlinolenic-alpha,acid

 

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Fats may be either solid or liquid at normal roomtemperature, depending on their structure andcomposition. Although the words "oils", "fats",and "lipids" are all used to refer to fats, "oils" is

usually used to refer to fats that are liquids atnormal room temperature, while "fats" is usuallyused to refer to fats that are solids at normalroom temperature. "Lipids" is used to refer toboth liquid and solid fats, along with other related

substances. 

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Fats or lipids are broken down in the body byenzymes called lipases produced in the pancreas 

Examples of edible animal fats are lard (pig fat),

fish oil, and butter . They are obtained from fatsin the milk, meat and under the skin of theanimal. Examples of edible plant fats are peanut,soya bean, sunflower, sesame, coconut, olive,and vegetable oils. Margarine and vegetable

shortening, which can be derived from the aboveoils, are used mainly for baking. These examplesof fats can be categorized into saturated fats andunsaturated fats.

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Importance for living organisms 

Vitamins A, D, E, and K are fat-soluble, meaningthey can only be digested, absorbed, andtransported in conjunction with fats. Fats are alsosources of essential fatty acids, an important

dietary requirement. Fats play a vital role in maintaining healthy skin and hair, insulating body organs against shock,maintaining body temperature, and promoting

healthy cell function.

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Fat also serves as a useful buffer towards a hostof diseases. When a particular substance,whether chemical or biotic—reaches unsafe levelsin the bloodstream, the body can effectively

dilute—or at least maintain equilibrium of —theoffending substances by storing it in new fattissue. This helps to protect vital organs, untilsuch time as the offending substances can bemetabolized and/or removed from the body by

such means as excretion, urination 

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Fats may be classified as saturated orunsaturated depending on the detailed structureof the fatty acids involved. Saturated fats have allof the carbon atoms in their fatty acid chainsbonded to hydrogen atoms, whereas unsaturated

fats have some of these carbon atoms double-bonded, so their molecules have relatively fewerhydrogen atoms than a saturated fatty acid of the same length

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Unsaturated fats may be further classifiedas monounsaturated (one double-bond) orpolyunsaturated (many double-bonds).Furthermore, depending on the location of the double-bond in the fatty acid chain,unsaturated fatty acids are classified as

omega-3 or omega-6 fatty acids. 

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3-omega

n−3 fatty acids (popularly referred to asω−3 fatty acids or omega-3 fattyacids) are a family of unsaturated fattyacids that have in common a final carbon –

carbon double bond in the n−3 position;that is, the third bond from the methyl end of the fatty acid.

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6-omega

n−6 fatty acids (popularly referredto as ω−6 fatty acids or omega-3fatty acids) are a family of 

unsaturated fatty acids that have incommon a final carbon –carbon

double bond in the n−6 position;

that is, the sixth bond from themethyl end of the fatty acid.

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Trans fats are a type of unsaturated fatwith trans-isomer bonds; these are rare innature and in foods from natural sources;they are typically created in an industrial

process called (partial) hydrogenation 

Trans fats may be monounsaturated or

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Trans fats may be monounsaturated orpolyunsaturated but never saturated.

Cis and trans are terms that refer to thearrangement of chains of carbon atomsacross the double bond. In the cis 

arrangement, the chains are on the sameside of the double bond, resulting in akink. In the trans arrangement, the chainsare on opposite sides of the double bond,and the chain is straight

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LIPOPROTEINS

The function of lipoprotein particles is totransport lipids (fats) and cholesterol around thebody in the aqueous blood, in which they wouldnot normally dissolve

The lipoprotein particles have hydrophilic groupsof phospholipids, cholesterol and apoproteinsdirected outward. Such characteristics makesthem soluble in the salt water-based blood pool.

Triglyceride-fats and cholesterol esters arecarried internally, shielded from the water by the

phospholipid monolayer and the apoproteins 

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LIPOPROTEINS

is a biochemical assembly that contains bothproteins and lipids.

Types o lipoproteins:

1. Chylomicrons: carry triacylglycerol (fat) from

the intestines to the liver, skeletal muscle, and to

adipose tissue. 

2. Very Low Density Lipoproteins (VLDL) (VLDL)

carry (newly synthesised) triacylglycerol from theliver to adipose tissue.

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3. intermediate-density lipoprotein (IDL) areintermediate between VLDL and LDL. They arenot usually detectable in the blood

4. low-density lipoprotein (LDL) carry cholesterol

from the liver to cells of the body. LDLs aresometimes referred to as the "bad cholesterol"lipoprotein.

5. high-density lipoprotein (HDL) collect

cholesterol from the body's tissues, and bring itback to the liver. HDLs are sometimes referred toas the "good cholesterol" lipoprotein

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Role in disease

Coronary heart disease is a multifactorialdisease, but diet is probably the fundamentalenvironmental factor. The pathological basis isatherosclerosis, which takes years to develop.

The characteristic material that accumulates inatherosclerosis is cholesterol ester. This andother lipids in the plaque, such as yellow

carotenoid pigments, come from the blood wherethey are carried on low density lipoprotein (LDL).

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Saturated fatty acids raise LDL-cholesterol; theseare mostly 12:0 (lauric), 14:0 (myristic), and16:0 (palmitic). Palmitic may be less potent butis the most abundant of these saturated fattyacids in foods. 18:0 (stearic) has little or no

cholesterol-raising effect

Polyunsaturated fatty acids (PUFA), (with two ormore double bonds) lower LDL-cholesterol. The

most abundant of these in foods is 18:2 (linoleic)which belongs to the -6 (omega-6 or n minus 6,n6) family of polyunsaturated fatty acids

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In the human body, high levels of triglycerides in the bloodstream have beenlinked to atherosclerosis, and, byextension, the risk of heart disease and

stroke. However, the relative negativeimpact of raised levels of triglyceridescompared to that of LDL:HDL ratios is asyet unknown

Another disease caused by hightriglycerides is pancreatitis 

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The American Heart Association has setguidelines for triglyceride levels:

InterpretationL/mmolLeveldL/mgLevel

Normal range, lowrisk

<1.69<150

borderline1.7-2.25150-199

High risk2.26-5.65250-499

Very high risk>5.65>500

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Reducing triglyceride levels 

To lower triglyceride levels, one may reduceconsumption of fats, alcohol and carbohydrates,particularly in rice, and engage in aerobicexercise

The American Heart Association notes that dietshigh in carbohydrates, with carbohydratesaccounting for more than 60% of the total caloric

intake, can increase triglyceride levels 

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Triglyceride levels are also reduced byomega-3 fatty acids from fish, flax seed oiland other sources. Recommendation inthe U.S. is that one ingest up to 3 grams a

day of such oils. In Europe therecommendation is for up to 2 grams.However, omega-3 consumption should bebalanced with omega-6 fatty acids, ideally

in a ω-6 /ω-3 ratio between 1:1 and 4:1(i.e., no more than four grams omega-6for every one of omega-3

Essential fatty acids

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Essential fatty acids 

Most fatty acids are non-essential,meaning the body can produce them asneeded, generally from other fatty acidsand always by expending energy to do so.However, in humans at least two fattyacids are essential and must be includedin the diet. An appropriate balance of 

essential fatty acids -omega-3 andomega-6 fatty acids -— seems also

important for health

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There are two families of EFAs: ω-3 (oromega-3 or n−3) and ω-6 (omega-6,n−6). Fats from each of these families areessential, as the body can convert oneomega-3 to another omega-3, forexample, but cannot create an omega-3

from omega-6 or saturated fats 

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The essential fatty acids start with the shortchain polyunsaturated fatty acids :

ω-3 fatty acids:

– α-Linolenic acid or ALA (18:3)

ω-6 fatty acids:

– Linoleic acid or LA (18:2)

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They form the starting point for the creation of longer and more desaturated fatty acids, whichare also referred to as long-chainpolyunsaturated fatty acids :

ω-3 fatty acids:– eicosapentaenoic acid or EPA (20:5)

– docosahexaenoic acid or DHA (22:6)

ω-6 fatty acids:

– gamma-linolenic acid or GLA (18:3)– dihomo-gamma-linolenic acid or DGLA (20:3)

– arachidonic acid or AA (20:4)

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Food sources 

Some of the food sources of ω-3 and ω-6fatty acids are fish and shellfish, flaxseed(linseed), hemp oil, soya oil, canola(rapeseed) oil, pumpkin seeds, sunflower

seeds, leafy vegetables, and walnuts. 

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Chapter 5:

 

Protein and amino acids

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Proteins, like carbohydrates, contain 16.8kilo joules (4 kilocalories) per gram as opposed tolipids which contain 37.8 kilojoules (9kilocalories) and alcohols which contain 29.4

kilojoules (7 kilocalories). The liver, and to amuch lesser extent the kidneys, can convertamino acids used by cells in protein biosynthesisinto glucose by a process known asgluconeogenesis.

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Dietary sources of protein include meats, eggs,nuts, grains, legumes, and dairy products such asmilk and cheese.

Of the 20 amino acids used by humans in protein

synthesis, 11 "nonessential" amino acids can besynthesized in sufficient quantities by the adultbody, and are not required in the diet (thoughthere are exceptions for some in special cases).The nine essential amino acids, plus arginine forthe young, cannot be created by the body and

must come from dietary sources 

\

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Most animal sources and certain vegetablesources have the complete complement of all theessential amino acids in adequate proportions.However, it is not necessary to consume a single

food source that contains all the essential aminoacids, as long as all the essential amino acids are

eventually present in the diet 

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Complete proteins, also known as high qualityproteins, "contain all the essential amino acids inamounts adequate for human use; it may or maynot contain all the others. Generally proteins

derived from animal foods (meats, fish, poultry,cheese, eggs, yogurt, and milk) are complete 

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Essentiality vs.conditionalessentiality in

humans 

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Protein quality assessment

Different proteins have different levels of biologicalavailability (BA) to the human body. Many methods havebeen introduced to measure protein utilization andretention rates in humans. They include biological value,net protein utilization, and PDCAAS (Protein DigestibilityCorrected Amino Acids Score) which was developed by theFDA as an improvement over the Protein Efficiency Ratio 

(PER) method.

These methods examine which proteins are most efficientlyused by the body. In general they conclude that animalcomplete proteins that contain all the essential amino acidssuch as milk, eggs, and meat are of most value to the body

Bi l i l l

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Biological value 

measure of the proportion of absorbed protein from a food which becomes incorporated into theproteins of the organism's body. It summariseshow readily the broken down protein can be used

in protein synthesis in the cells of the organism. 

A ratio of nitrogen incorporated into the bodyover nitrogen absorbed gives a measure of 

protein 'usability' - the BV. 

N t t i tili ti

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Net protein utilization 

The net protein utilization, or NPU, is the ratioof amino acid converted to proteins to the ratio of amino acids supplied

NPU = ((0.16 × (24 hour protein intake in

grams)) - ((24 hour urinary urea nitrogen) + 2) -(0.1 × (ideal body weight in kilograms))) / (0.16

× (24 hour protein intake in grams)) 

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As a value, NPU can range from 1 to 0, with a value of 1indicating 100% utilization of dietary nitrogen as proteinand a value of 0 an indication that none of the nitrogen

supplied was converted to protein 

Protein Digestibility Corrected Amino Acid

)

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Score (PDCAAS) 

is a method of evaluating the protein qualitybased on the amino acid requirements of humans. The PDCAAS rating is a fairly recentevaluation method; it was adopted by the USFood and Drug Administration (FDA) and the

Food and Agricultural Organization of the UnitedNations/World Health Organization (FAO/WHO) in1993 as "the preferred 'best'" method todetermine protein quality. These organizationshave suggested that other methods for

evaluating the quality of protein are inferior.

PDCAAS l f t i

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PDCAAS value of protein 

A PDCAAS value of 1 is the highest, and 0 the lowest as thetable demonstrates the ratings of common foods below.

whey(1.0)

Egg white(1.0)

casein(1.0)

milk(1.0)

soy protein isolate(1.0)

beef (0.92)

soybean(0.91

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tubercules(0.74)vegetables(0.74)

legumes in general(0.69)

kidney beans(0.68)

rye(0.68)cereals and derivatives(0.58)

whole wheat(0.54)

lentils(0.52)

peanuts(0.52)hemp(0.46)

seitan(0.25)

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Egg whites have been determined to have thestandard biological value of 100 (though somesources may have higher biological values),which means that most of the absorbed nitrogen

from egg white protein can be retained and usedby the body. The biological value of plant proteinsources is usually considerably lower than animalsources.For example, corn has a BA of 70 while

peanuts have a relatively low BA of 40

 

Digestion

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Digestion 

Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, andcontinued by trypsin and chymotrypsin in

the intestine. The amino acids and theirderivatives into which dietary protein isdegraded are then absorbed by the

gastrointestinal tract 

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The absorption rates of individual amino acids arehighly dependent on the protein source; forexample, the digestibility of many amino acids inhumans differ between soy and milk proteins andbetween individual milk proteins, beta-

lactoglobulin and casein.For milk proteins, about50% of the ingested protein is absorbed betweenthe stomach and the jejunum and 90% isabsorbed by the time the digested food reachesthe ileum. 

Dietary requirements

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Dietary requirements 

According to the recently updated US/CanadianDietary Reference Intake guidelines, women aged19 –70 need to consume 46 grams of protein perday, while men aged 19 –70 need to consume 56grams of protein per day to avoid a deficiency.The difference is because men's bodies generallyhave more muscle mass than those of women, orthis may be attributed to weight difference bytaking 0.8 g (of protein)/kg of healthy bodyweight.

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If enough energy is not taken in through diet, asin the process of starvation, the body will useprotein from the muscle mass to meet its energyneeds, leading to muscle wasting over time. If 

the individual does not consume adequateprotein in nutrition, then muscle will also wasteas more vital cellular processes (e.g. respirationenzymes, blood cells) recycle muscle protein for

their own requirements

 

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Other recommendations suggest 0.8 gram of protein per kilogram of healthy bodyweight perday while other sources suggest that higherintakes of 1-1.4 grams of protein per kilogram of 

bodyweight for enhanced athletes or those with alarge muscle mass 

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How much protein needed in a person's daily dietis determined in large part by overall energyintake, as well as by the body's need for nitrogenand essential amino acids. Physical activity and

exertion as well as enhanced muscular massincrease the need for protein. Requirements arealso greater during childhood for growth anddevelopment, during pregnancy or when breast-feeding in order to nourish a baby, or when the

body needs to recover from malnutrition ortrauma or after an operation. 

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Dr. Latham, director of the Program inInternational Nutrition at Cornell University claims that malnutrition is a frequent cause of death and disease in third world countries.

Protein-energy malnutrition (PEM) affects 500million people and kills 10 million annually. Insevere cases white blood cell numbers declineand the ability of leukocytes to fight infectiondecreases

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Protein deficiency is relatively rare in developedcountries but some people have difficulty gettingsufficient protein due to poverty. Proteindeficiency can also occur in developed countriesin people who are dieting or crash dieting to loseweight, or in older adults, who may have a poordiet. Convalescent people recovering fromsurgery, trauma, or illness may become proteindeficient if they do not increase their intake tosupport their increased needs

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Excess consumption

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Excess consumption 

The body is unable to store excess protein.Protein is digested into amino acids which enterthe bloodstream. Excess amino acids areconverted to other usable molecules by the liverin a process called deamination. Deamination

converts nitrogen from the amino acid intoammonia which is converted by the liver intourea in the urea cycle. Excretion of urea isperformed by the kidneys. These organs cannormally cope with any extra workload but if 

kidney disease occurs, a decrease in protein willoften be prescribed

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Many researchers think excessive intake of protein forces increased calcium excretion. If there is to be excessive intake of protein, it isthought that a regular intake of calcium would be

able to stabilize, or even increase the uptake of calcium by the small intestine, which would be

more beneficial in older women 

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Specific proteins are often the cause of allergies and allergic reactions to certain foods. This isbecause the structure of each form of protein isslightly different; some may trigger a responsefrom the immune system while others remainperfectly safe. Many people are allergic to casein,the protein in milk; gluten, the protein in wheatand other grains; the particular proteins found in

peanuts; or those in shellfish or other seafoods.

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Dietitians may recommend that mineralsare best supplied by ingesting specificfoods rich with the element(s) of interest.Sometimes minerals are ingested as

mineral dietary supplements, the mostcommon being iodine in iodized salt. 

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Potassium (K)

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Potassium (K)

Elemental potassium does not occur in naturebecause it reacts violently with water

Potassium is the second least dense metal; only

lithium is less dense. It is a soft, low-meltingsolid that can easily be cut with a knife. Freshlycut potassium is silvery in appearance, but in air

it begins to tarnish toward grey immediately 

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Recommended Dietary Allowances forpotassium is 4700mg 

Potassium cations in the body

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Potassium cations in the body Potassium cations are important in neuron (brain and nerve) function, and in influencing osmoticbalance between cells and the interstitial fluid,with their distribution mediated in all animals(but not in all plants) by the so-called Na+/K+-

ATPase pump Potassium is also important in preventing musclecontraction and the sending of all nerve impulses

in animals through action potentials.

 

Adequate intake

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 Adequate intake 

Foods with high sources of potassium includeorange juice, potatoes, bananas, avocados,tomatoes, broccoli, soybeans, brown rice, garlic and apricots, although it is also common in most

fruits, vegetables and meats. 

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Excess

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Excess

Symptoms are fairly nonspecific and generallyinclude malaise, palpitations and muscleweakness; mild hyperventilation may indicate acompensatory response to metabolic acidosis,which is one of the possible causes of hyperkalemia. Often, however, the problem isdetected during screening blood tests for amedical disorder, or it only comes to medicalattention after complications have developed,

such as cardiac arrhythmia or sudden death 

Chloride

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Chloride

Chloride is a chemical the human body needs formetabolism (the process of turning food intoenergy). It also helps keep the body's acid-basebalance. The amount of chloride in the blood is

carefully controlled by the kidneys. 

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Recommended DietaryAllowances for chloride is2300mg

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Dietary sources include table salt(sodium chloride, the main source),vegetables, milk, and spinach.

Insufficiency

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Patients with low-level, chronic water intoxicationare often asymptomatic, but may have symptoms related to the underlying cause. Severehyponatremia in acute or chronic form may causeosmotic shift of water from the plasma into thebrain cells. Typical symptoms include nausea,

vomiting, headache and malaise. As thehyponatremia worsens, conf usion, diminishedreflexes, convulsions, stupor or coma may occur

Excess

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Often hyperchloremia does not produce anysymptoms. However, hyperchloremia issometimes associated with excess fluid loss suchas vomiting and diarrhea. If the sufferer were tobe a diabetic, hyperchloremia could lead to poorcontrol of blood sugar levels, which could causethem to become elevated. Hyperchloremia can besymptomatic with signs of Kussmaul's breathing,

weakness, and intense thirst 

Sodium

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Sodium cations are important in neuron (brain and nerve) function, and in influencing osmoticbalance between cells and the interstitial fluid,

RDA

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Recommended Dietary Allowances forsodium is 1500mg

 Insufficiency

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Nausea vomiting 

headache and malaise .

In acute case:

Confusion  

convulsions  

stupor or coma may occur

Excess

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Excess

Lethargy  Weakness

irritability, and edema .

With more severe elevations of the sodium level: 

seizures and coma may occur 

Calcium

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Calcium is an important component of ahealthy diet and a mineral necessary for life.

"Calcium plays an important role in building

stronger, denser bones early in life and keepingbones strong and healthy later in life.” 

Approximately ninety-nine percent of the body's

calcium is stored in the bones and teeth 

 RDA

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Recommended Dietary Allowances forcalcium is 1000mg

Sources

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Dairy products: milk and cheese, are a well-known source of calcium. 

nuts and seeds (like almonds and sesame) 

blackstrap molasses  ; beans; oranges; figs;okra; rutabaga  ; broccoli 

Insufficiency 

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Perioral tingling  and parasthesia, 'pinsand needles' sensation over the extremities of hands and feet. This is the earliest symptom of hypocalcemia.

LATER: osteoporosis and rickets. 

Excess

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Fatigue 

anorexia 

nausea vomiting 

pancreatitis and increased urination 

Phosphorus

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p

is a component of bones and energy processing(ATP) and many other functions. 

RDA

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Recommended Dietary Allowances for Phosphorusis 700mg

Insufficiency

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Muscle dysfunction and weakness.

respiratory depression due to respiratory muscleweakness.

Mental status changes. This may range fromirritability to gross confusion, delirium  ,and coma  .

White cell dysfunction, causing worsening of infections 

Magnesium

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Magnesium is the 11th most abundant elementby mass in the human body; its ions are essentialto all living cells, where they play a major role inmanipulating important biological polyphosphate

compounds like ATP, DNA, and RNA. 

RDA

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Recommended Dietary Allowances for Magnesiumis 420mg

Insufficiency

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Symptoms of magnesium deficiency include:hyperexcitability  , muscle weakness and

tiredness  . 

Excess

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Weakness, nausea and vomitingImpaired breathing

Hypotension 

Zinc

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required for several enzymes such ascarboxypeptidase, liver alcohol dehydrogenase,and carbonic anhydrase.

The concentration of zinc in plants varies based

on levels of the element in soil. When there isadequate zinc in the soil

Sources

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the food plants that contain the most zinc arewheat (germ and bran)

Zinc is also found in beans  , nuts, almonds,

whole grains, pumpkin seeds  , sunflowerseeds

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Insufficiency

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Signs of zinc deficiency include hairloss, skin lesions  , diarrhea,and wasting of body tissues.

Excess

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it causes a severe hemolytic anemia,also liver or kidney damage;vomiting and diarrhoea are possible

symptoms

Iron

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is required for many proteins andenzymes, notably hemoglobin.

Sources

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Dietary sources include red meat, leafy greenvegetables, fish (tuna, salmon), eggs, dried

fruits, beans, whole grains, and enriched grains. 

RDA

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Recommended Dietary Allowances for iron is8 mg

Insufficiency

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Most commonly, people with anemia report non-specific symptoms of a feeling of weakness, orfatigue, general malaise and sometimes poorconcentration. They may also report shortness of 

breath. 

Excess

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Organs commonly affected byhaemochromatosis (accumulation of iron in the body due to any cause) are theliver, heart and endocrine glands

Iodine

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The thyroid gland actively absorbs iodide fromthe blood to make and release these hormonesinto the blood, actions which are regulated by a

second hormone TSH from the pituitary. 

RDA

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Recommended Dietary Allowances for iodineis 150 µg 

Insufficiency

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goiter 

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RDA

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Recommended Dietary Allowances forcopper is 900 µg 

Insufficiency

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Copper deficiency can cause asyndrome of anemia 

Selenium 

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Selenium also plays a role in the functioning of the thyroid gland by participating as a cofactor for the three known thyroid hormone deiodinases 

Dietary selenium comes from nuts, cereals, meat,fish, and eggs. Brazil nuts are the richestordinary dietary source (though this is soil-dependent, since the Brazil nut does not require

high levels of the element for its own needs). 

RDA

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Recommended Dietary Allowances forselenium is 55 µg 

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Molybdenum

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The most important use of the molybdenum inliving organisms is as a metal at the active site incertain enzymes.

the nitrogenase enzyme, which is involved in theterminal step of reducing molecular nitrogen,usually contains molybdenum in the active site

RDA

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Recommended Dietary Allowances formolybdenum is 45 µg 

Insufficiency

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The amount of molybdenum required is relativelysmall, and molybdenum deficiency usuallydoesn't occur in natural settings. However, it canoccur in individuals receiving parenteral nutrition 

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Chapter 7: 

Vitamins

 

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A vitamin is an organic compound required as anutrient in tiny amounts by an organism. 

The term 'vitamin' first became popular in the

early 1800's as a contraction  of the words'vital' and 'mineral', though the actual meaning of the word has developed somewhat since that

time 

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Vitamin A 

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Promotes healthy bone growth, vision,reproduction, cell divisionand  specialization and helps regulate theimmune system.

Sources 

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whole milkliver

eggs

some fortified breakfast cerealscarrots

sweet potatoes

spinach

most darkly colored fruit and vegetables.

Vitamin B1 

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Also known as thiamineis essential in converting foods into energy,

helps supports the normal function of thenervous system, muscles and heart and promotes

normal growth and development. 

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It is also thought to help regulate appetite.

Present in moderate amounts in all foods,the best sources are whole grains and

fortified cereals 

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It is essential for healthy skin, nails and hairgrowth, thyroid activity, healing of wounds and

general good health. 

Sources

Li

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Liverwhole grainsgreen leaf vegetablesmilk

yeastcheeseoily fisheggs

enriched cerealsalmonds and mushrooms.

Vitamin B3 

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Also known as niacin is also part of the vitamin Bcomplex that is primarily involved into convertingfood into energy.

Regulates circulation, hormone production, thedigestive and nervous systems, promotes healthyskin.

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Regular alcohol drinkers and vegetarians shouldconsider taking a B3 (Niacin) supplement asalcohol inhibits niacin absorption and diets

lacking protein are likely to be B3 deficient. 

Sources

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beef liverPork

turkey

Chicken

vealoily fish

beets

peanutsstrawberries.

Vitamin B6 

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Also known as pyridoxine is necessary to balancethe hormonal changes in women, assists in thegrowth of new cells and the functioning of theimmune system, converting food into energy,

and in controlling moods, behavior. 

It i i l d i d bl d ll d ti

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It is involved in red blood cell production,preventing skin problems and in fighting certainheart difficulties.

Sources 

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Eggschicken

yeast

carrotsfish

liver

peaswalnuts .

Vitamin B12 

C t i b lt d i l k b l i

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Contains cobalt and is also known as cobalamin.The primary functions are to maintain a healthy

nervous system and to produce red blood cells 

S ff f B12 d fi i hi h h

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Sufferers from B12 deficiency, which can havemild to severe symptoms, may be unable toabsorb the vitamin through normal food intakeand will have to take ongoing regular injections

to alleviate the problem. 

Sources 

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Meatdairy products

eggs 

Vitamin C 

Absorbic Acid The human body is unable to store

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 Absorbic Acid . The human body is unable to storeVitamin C and unless replenished constantly,symptoms, the most commonly known of whichis scurvy that can become fatal, will quicklyoccur.

It is important in forming collagen that givesstructure to bones, cartilage, muscle and bloodvessels and in maintaining bones and teeth, and

in the absorption of iron.

Sources are most fruits and vegetables served

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Sources are most fruits and vegetables servedraw if possible, Vitamin C dissolves in water so if the food must be cooked use the minimal amountof water by steaming or microwaving for as short

a time as possible. 

Vitamin D 

The source of this vitamin is best known as being

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The source of this vitamin is best known as beingfrom sunlight, or more accurately, as being madein the body by exposure to UV rays.

It promotes the calcium and phosphorous that

are vital in forming and maintaining strongbones.

It may also be involved in regulating cell growthand maintaining a healthy immune system.

Sources

Exposure to sunlight (which should be carefully

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Exposure to sunlight (which should be carefullylimited) is the principal source

most dairy products contain only limitedamounts

better sources include oily fish, fortified cereals,eggs, and beef liver.

Vitamin E 

A is a powerful source of anti oxidants and as

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A is a powerful source of anti – oxidants and as

such acts as a barrier to poisons and diseasesthat can damage the body.

It is also recognized as being involved in immunesystem function, DNA repair, the protection of blood cells, the nervous system, muscles and theeye retinas from free radical damage.

Sources 

Nuts

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Nuts

green vegetables (spinach, broccoli, sprouts)

Eggs

whole meal products

soya beansvegetable oils and particularly olive oil.

Vitamin K 

This vitamin plays an essential role in the

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This vitamin plays an essential role in theproduction of coagulation proteins, meaning thatit is responsible for regulating the ability of theblood to clot.

A deficiency may occur in any age group, but ismore often found in infants. Excessive bleeding isthe principal symptom.

Sources 

green vegetables

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green vegetables

asparagus

oats

oils, such as olive oil

Water 

Essential to the survival of all organisms water

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Essential to the survival of all organisms, waterhas historically been an important and life-sustaining drink to humans.

water composes approximately 70% of thehuman body by mass. It is a crucial componentof metabolic processes and serves as a solvent 

for many bodily solutes. 

the British Dietetic Association recommends 1 8

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the British Dietetic Association recommends 1.8liters

The United States Environmental ProtectionAgency has determined that the average adult

actually ingests 2.0 liters per day 

Water quality and contaminants 

Throughout most of the world the most common

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Throughout most of the world, the most commoncontamination of raw water sources is fromhuman sewage and in particular human faecalpathogens and parasites.

In 2006, waterborne diseases were estimated tocause 1.8 million deaths each year while about1.1 billion people lacked proper drinking water

Water treatment

UV radiation

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UV radiation

Chlorination

Ozone

Heating

Filtration

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Requirements

Humans can survive for several weeks without

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Humans can survive for several weeks withoutfood, but for only a few days without water.

The exact amount of water a human needs ishighly individual, as it depends on the conditionof the subject, the amount of physical exercise,and on the environmental temperature and

humidity 

In the US, the reference daily intake (RDI) for

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In the US, the reference daily intake (RDI) forwater is 3.7 litres per day for human males olderthan 18, and 2.7 litres for human females olderthan 18 including water contained in food,beverages, and drinking water.

It is a common misconception that everyoneshould drink two litres (68 ounces, or about eight8-oz glasses) of water per day and is not

supported by scientific research. 

Water intoxication (also known as hyper-

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Water intoxication (also known as hyperhydration or water poisoning) is a potentiallyfatal disturbance in brain functions that resultswhen the normal balance of electrolytes in thebody is pushed outside of safe limits by over-

consumption of water.

Normal, healthy (both physically andnutritionally) individuals have little reason to

worry about accidentally consuming too muchwater 

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Healthy diet A healthy diet is one that helps maintain or

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y p

improve health. It is important for the preventionof many chronic health risks such as: obesity,heart disease, diabetes, and cancer 

A healthy diet involves consuming appropriate

amounts of all nutrients, and an adequateamount of water. Nutrients can be obtained frommany different foods, so there are a wide varietyof diets that may be considered healthy diets.

Processed foods 

Since the Industrial Revolution some two

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Since the Industrial Revolution some twohundred years ago, the food processing industryhas invented many technologies that both helpkeep foods fresh longer and alter the fresh stateof food as they appear in nature.

Cooling is the primary technology used tomaintain freshness, whereas many moretechnologies have been invented to allow foods

to last longer without becoming spoiled. 

These latter technologies include pasteurisation,

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a o og ud pa u a o ,autoclavation, drying, salting, and separation of various components, and all appear to alter theoriginal nutritional contents of food.

 

Food processing techniques like: heat treatment

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p g qand separation can cause several changes infoods like:

Loss of nutritional value like vitamins andminerals

Loss of antioxidants 

Because of reduced nutritional value, processed

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, pfoods are often 'enriched' or 'fortified' with someof the most critical nutrients (usually certainvitamins) that were lost during processing.

In addition, processed foods often containpotentially harmful substances such as oxidized

fats and trans fatty acids 

dramatic example of the effect of food processing

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p p gon a population's health is the history of epidemics of beri-beri in people subsisting onpolished rice. Removing the outer layer of rice bypolishing it removes with it the essential vitamin

thiamine, causing beri-beri. 

Another example is the development of scurvy 

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p p yamong infants in the late 1800s in the UnitedStates. It turned out that the vast majority of sufferers were being fed milk that had been heat-treated (as suggested by Pasteur) to control

bacterial disease. Pasteurisation was effectiveagainst bacteria, but it destroyed the vitamin C. 

As mentioned, lifestyle- and obesity-related

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, y ydiseases are becoming increasingly prevalent allaround the world. There is little doubt that theincreasingly widespread application of somemodern food processing technologies has

contributed to this development. 

In any known profit-driven economy, healthconsiderations are hardly a priority; effective

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considerations are hardly a priority; effectiveproduction of cheap foods with a long shelf-life ismore the trend. In general, whole, fresh foodshave a relatively short shelf-life and are lessprofitable to produce and sell than are more

processed foods. 

Thus the consumer is left with the choice

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between more expensive but nutritionallysuperior whole, fresh foods, and cheap, usuallynutritionally inferior processed foods. Becauseprocessed foods are often cheaper, more

convenient (in both purchasing, storage, andpreparation

Healthy eating pyramid 

guide developed by the Harvard School of Public

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Health, suggesting how much of each foodcategory one should eat each day. The healthyeating pyramid is intended to provide a bettereating guide than the widespread food guide

pyramid created by the USDA. 

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Weight assessment

assessment of overweight involves using three

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key measures:body mass index (BMI) 

waist circumference, and

risk factors for diseases and conditionsassociated with obesity 

The BMI is a measure of your weight relative to

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your height and waist circumference measuresabdominal fat. Combining these with informationabout your additional risk factors yields your risk

for developing obesity-associated diseases. 

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 BMI= mass/(Height)2

Mass in Kilograms

Height in meter

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 Waist Circumference 

Determine your waist circumference by placing a

l d

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measuring tape snugly around your waist. It is agood indicator of your abdominal fat which isanother predictor of your risk for developing riskfactors for heart disease and other diseases. This

risk increases with a waist measurement of over40 inches in men and over 35 inches in women 

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* 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. 

Ch 9

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Chapter 9 

Introduction to Chronic Diseasesof Lifestyle, Obesity, and

Diabetes

 

Introduction

increased consumption of energy-dense

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diets high in fat, particularly saturated fat,and low in unrefined carbohydrates.

These patterns are combined with a

decline in energy expenditure that isassociated with a sedentary lifestylemotorized transport, labour-savingdevices in the home, the phasing out of 

physically demanding manual tasks in theworkplace

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Importance of physical activity

Energy expenditure through physical

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activity is an important part of the energybalance equation that determines bodyweight. A decrease in energy expenditure

through decreased physical activity islikely to be one of the major factorscontributing to the global epidemic of 

overweight and obesity.

Physical activity has great influence onf f

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body composition on the amount of fat,muscle and bone tissue.

To a large extent, physical activity andnutrients share the same metabolicpathways and can interact in various waysthat influence the risk and pathogenesis of 

several chronic diseases.

Cardiovascular fitness and physical activityh b h d f l

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have been shown to reduce significantlythe effects of overweight and obesity onhealth.

Physical activity and food intake are bothspecific and mutually interacting behaviorsthat are and can be influenced partly by

the same measures and policies.

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Chronic diseases

The burden of chronic diseases is rapidly

i i ld id It h b

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increasing worldwide. It has beencalculated that, in 2001, chronic diseasescontributed approximately 60% of the56.5 million total reported deaths in theworld and approximately 46% of theglobal burden of disease

The proportion of the burden of NCDs ist d t i t 57% b 2020

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expected to increase to 57% by 2020.Almost half of the total chronic diseasedeaths are attributable to cardiovascular

diseases; obesity and diabetes are alsoshowing worrying trends, not onlybecause they already affect a largeproportion of the population, but also

because they have started to appearearlier in life

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 Chapter 10

Cardiovascular Diseases

 

Cardiovascular Disease (CVD)

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Cardiovascular Disease (CVD)includes dysfunctional conditions of the heart, arteries, and veins thatsupply oxygen to vital life-sustaining

areas of the body like the brain, theheart itself, and other vital organs. If oxygen doesn't arrive the tissue or

organ will die

Ischemic Heart Disease is the technical term for

obstruction of blood flow to the heart In general

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obstruction of blood flow to the heart. In generalthis results because excess fat or plaque depositsare narrowing the veins that supply oxygenatedblood to the heart. Excess buildup of fat or

plaque are respectively termed arteriosclerosisand atherosclerosis. Equally significant would beinadequate oxygen flow to the brain, whichcauses a stroke 

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