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Vitamin/Mineral:(How
Much/day)Why You Need It:
Best Sources To Find
It:
Vitamin A& Beta
Carotene (700 mcg)
Development of bonesand teeth grow vitamin
A prevents poor vision
at night or when light
intensity is low and
helps to fight
infections. Lack of
vitamin A also causes
blindness in children. A
woman needs to eat
plenty of vitamin A-rich
food during pregnancy
and while
breastfeeding.
Dark yellow andgreen leafyvegetables and
Liver, milk, eggs,
carrots, spinach,
green and yellow
vegetables, broccoli,
potatoes, pumpkin,
yellow fruits,
cantaloupe
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yellow fruits
contain lots of
vitamin A. Name
some of thesevegetables and
fruits.
Vitamin D(5 mcg)
Helps body use calcium
and phosphorus;
promotes strong teeth
and bones
Milk, fatty fish
Vitamin E (15 mg)
Helps body form and
use red blood cells and
muscles
Vegetable oil, wheat
germ, nuts, spinach,
fortified cereals
Vitamin C (80 - 85 mg)
An antioxidant that
protects tissues from
damage and helpsbody absorb iron;
builds healthy immune
system
Citrus fruits, bell
peppers, green
beans, strawberries,
papaya, potatoes,
broccoli, tomatoes
Thiamin/B1 (1.4 mg)
Raises energy level and
regulates nervous
system
Whole grain,
fortified cereals,
wheat germ, organ
meats, eggs, rice,pasta, berries, nuts,
legumes, pork
Riboflavin/B2 (1.4 mg)Maintains energy,
good eyesight, healthy
Meats, poultry, fish,
dairy products,
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skin fortified cereals,
eggs
Niacin/B3 (18 mg)Promotes healthy skin,
nerves and digestion
High-protein foods,
fortified cereals and
breads, meats, fish,
milk, eggs, peanuts
Pyridoxine/B6 (1.9 mg)
Helps form red blood
cells; helps with
morning sickness
Chicken, fish, liver,
pork, eggs,
soybeans, carrots,
cabbage,
cantaloupe, peas,spinach, wheat
germ, sunflower
seeds, bananas,
beans, broccoli,
brown rice, oats,
bran,
peanuts,walnuts
Folic Acid/Folate (600
mcg)
Helps support the
placenta, and
preventsspina
bifidaand other neural
tube defects
Oranges, orange
juice, strawberries,
green leafy
vegetables, spinach,
beets, broccoli,
cauliflower, fortified
cereals, peas, pasta,
beans, nuts
Calcium (1,000 - 1,300
mg)
Creates strong bones
and teeth, helps
prevent blood clots,
helps muscles and
Yogurt, milk,
cheddar cheese,
calcium-fortified
foods like soy milk,
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nerves function juices, breads,
cereals, dark green
leafy vegetables,
canned fish withbones
Iron (27 mg)
Helps in the production
of hemoglobin;
preventsanemia, low
birth weight,
andpremature birth
Beef, pork, dried
beans, spinach, dried
fruits, wheat germ,
oatmeal or grains
fortified with iron
Protein(60 mg)
Helps in the production
of amino acids; repairs
cells
Most animal foods,meat, poultry, eggs,
dairy products,
veggie burgers,
beans, legumes, nuts
Zinc
Helps produce insulin
and enzymesRed meats, poultry,
beans, nuts, whole
grains, fortified
cereals, oysters,
dairy products
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Iodine prevents goiter (swelling of the neck) and other problems in
adults. Lack of iodine in a pregnant woman can cause her child to have
cretinism, a disability that affects thinking and physical features.
The easiest way to get enough iodine is to use iodized salt instead of
regular salt (Figure 14.6). It is available in packet form labeled Iodized
salt in many market places.
2. No, herbal supplements are not the best option because herbal
supplement can sometime cross the placenta and have some effects
on the baby. Some herbal that can cross the placenta are:
Saw Palmetto - when used orally has hormonal activity. It mayaffect pregnancy-related hormones and lead to complication.
Goldenseal - when used orally may cross the placentaGoldensealGoldenseal is commonly used in hopes of passing a drug test
when drugs are in fact present in the system and is commonly
used for upper respiratory tract infections, colds, and stuffy noses.
Goldenseal may also be used for digestive problems, ulcers,
diarrhea, gas and constipation. Goldenseal or breastfeeding as it
may be unsafe for the baby. A dangerous chemical found in
goldenseal can pass through the placenta or into the breast milk.
Infants exposed to goldenseal have exhibited brain damagebecause of it.
Dong Quai - when used orally, due to uterine stimulant andrelaxant effects because it is known to cause uterine contractions
that could trigger premature labor or cause a miscarriage.
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Ephedra - when used orally Yohimbe - when used orally
Pay D Arco - when used orally in large doses; contraindicated
Passion Flower - when used orally Black Cohosh - when used orally in pregnant women who are not
at term
Blue Cohosh - when used orally; uterine stimulant and can inducelabor
Roman Chamomile - when used orally in medicinal amounts Pennyroyal - when used orally or topically
3. Nitrogen balance,
Nitrogen balance,
The relationship between the amount of nitrogen taken into the body,
usually as food, and that excreted from the body in urine and feces.
Most of the body's nitrogen is incorporated into protein. Positive
nitrogen balance, which occurs when the intake of nitrogen is greater
than its excretion, implies tissue formation and growth. Negative
nitrogen balance, which occurs when more nitrogen is excreted than is
taken in, indicates wasting or destruction of tissue.
n a determination made about the body's ability to meet its protein
needs which is reached by comparing the amount of nitrogen taken in
with the amount discharged via urine, hair, skin, or perspiration.
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nitrogen balance, negative,
n a condition in which nitrogen output exceeds nitrogen intake,
resulting in the body's need to draw on its own stores of protein for
energy; may be caused by dietary imbalances, illness, infection, anxiety,
or stress.
nitrogen balance, positive,
n a body condition in which nitrogen intake exceeds nitrogen output; a
normal state for children, pregnant women, or individuals recovering
from illness or surgery, whose bodies require extra protein in order to
build tissue.
Nitrogen balance should be positive in children, young adult, pregnant
woman and people recovering from surgery and injury. Also in athletes
people because they need the excess of nitrogen in order to build their
tissue.
In non pregnant woman or male adult the nitrogen balance should be
at equilibrium.
5.Negative nitrogen balance, that person's nitrogen output is greaterthan his nitrogen input. Because protein is the only macronutrient
containing a nitrogen molecule, a negative nitrogen balance can be a
sign of inadequate protein consumption and malnutrition.
6. A)
The Recommended Daily Allowance (RDA) of iron for people who are
not iron deficient varies by age group and other risk factors. (Iron
supplements are rarely recommended in people without evidence of
iron deficiency or anemia.) The RDA for iron intake is:
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Infants 0 - 6 months: 0.27 mg Infants 7 - 12 months: 11 mg
Children 1 - 3 years old: 7 mg
Children 4 - 8 years old: 10 mg Children 9 -13 years old: 8 mg Teenage boys (14 - 18 years): 11 mg Teenage girls (14 - 18 years): 15 mg Men 19 - 50 years old: 8 mg Women 19 - 50 years old: 18 mg Pregnant women: 27 mg Older men and women (over age 50): 8 mg
B)
Age Group Hemoglobin Count (gm/dl)
Newborn Babies 17- 22
Children 11-13
Adults (Male) 14-18
Adults (Female) 12-16
Elderly (Male) 12.4-14.9
Elderly (Female) 11.7-13.8
C) At birth, the normal range of hematocrit can be anywhere from 42 to
64.
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After birth up until 1 month of age, the "normal" range is between 31
and 67.
Between 1 to 2 months, the normal range is between 28 to 55.
Between 2 and 6 months, the normal range is between 28 and 42.
Between 6 months to two years, the normal range is 33 to 40.
Between 2 to 6 years the normal range is between 34 to 40.
Between 6 to 12 years, the normal range is between 35 to 45.
For females between ages 12 and 18, the normal range is between 36to 46.
For males between ages 12 and 18, the normal range is between 37
and 49.
esults indicating low hematocrit levels, cannot be ignored and is a
cause for worry. Low hemoglobin levels and pregnancy is commonly
associated with a decreased hematocrit range. Other reasons areelaborated below:
Anemia: This condition causes a significant reduction in the number of
red blood cells. When the RBC count is too less, there is a sharp drop in
hematocrit levels. In fact, a person with low hematocrit levels is said to
be suffering from anemia.
Hemolysis: This condition brings premature death of red blood cells. In
other words, hemolysis decreases the life span of red blood cells,
leading to significant reduction in RBC count, thereby causing lowered
hematocrit levels in the body.
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Nutritional Deficiencies: Deficiency of essential nutrients like vitamin
B12, iron and folate can also reduce the number of red blood cells in
the blood.
Chemotherapy Drugs: Chemotherapy drugs that are commonly used to
treat cancer can also have a negative impact on normal RBC count.
These drugs that are formulated to kill cancer cells may also destroy
healthy red blood cells. This in turn may reduce volume of red blood
cells (RBCs) in the blood.
Renal Failure: Less than normal hematocrit values may also signal renal
failure, in which the kidneys fail to perform their necessary function.
Renal failure can be either acute (rapid decrease in kidney function) or
may occur gradually over a period of time. In either case, the amount of
space occupied by red blood cells in the blood is bound to reduce
substantially.
People suffering from rheumatoid arthritis and leukemia have also
been diagnosed with hematocrit range that is far less than normal. So,
low or high hematocrit levels have to be taken seriously, as they
indicate overall health is not in good shape.
The hematocrit represents the volume of red blood cells in 100ml of
blood and is therefore reported as a percentage. A low hematocrit andhemoglobin usually indicates decreased production, excessive loss, or
destruction of red blood cells. Anemia is not a disease, but a term
indicating insufficient hemoglobin to deliver oxygen to the cells. It is
always a secondary phenomenon.
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Optimum values in an adult male are 42.0 to 48.0% and in an adult
female is 39.0 to 45.0%.
The conditions associated with an increased or decreased hematocrit
are the same as for hemoglobin. In addition, it has been suggested that
an elevated hematocrit may be due to spleen hyperfunction, and a
reduced hematocrit may indicate low thymus function.
D) Recommended Dietary Allowances (RDAs) for Folate [2]
Age Male Female Pregnant Lactating
Birth to 6months*
65 mcgDFE*
65 mcgDFE*
712 months* 80 mcg
DFE*
80 mcg
DFE*
13 years 150 mcg
DFE
150 mcg
DFE
48 years 200 mcg
DFE
200 mcg
DFE
913 years 300 mcg
DFE
300 mcg
DFE
1418 years 400 mcg
DFE
400 mcg
DFE
600 mcg
DFE
500 mcg
DFE
19+ years 400 mcg
DFE
400 mcg
DFE
600 mcg
DFE
500 mcg
DFE
* Adequate Intake (AI)
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Age Male Female Pregnancy Lactation
Birth to 6
months
Not possible to
establish*
Not possible to
establish*
712
months
Not possible to
establish*
Not possible to
establish*
13 years 300 mcg 300 mcg
4 8 years 400 mcg 400 mcg
913 years 600 mcg 600 mcg
1418 years 800 mcg 800 mcg 800 mcg 800 mcg
19+ years 1,000 mcg 1,000 mcg 1,000 mcg 1,000
mcg
* Breast milk, formula, and food should be t
7.Folic acid is used to make the extra blood your body needs duringpregnancy. All women of childbearing age should consume 400
micrograms of folic acid a day.
When should I start taking folic acid?
You should start taking folic acid prior to getting pregnant even if you
are not trying to conceive. Neural tube defects usually develop in thefirst 28 days of pregnancy, often before a woman even knows that she
is pregnant. If you find you are pregnant and have not been taking folic
acid, you should start now to help prevent any neural defects in the
first three months of pregnancy.
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What are the risks of not taking folic acid?
The absence of folic acid increases the possibility of a neural tube
defect, a defect in the development of the spinal cord.
Spina bifidais a condition in which the spinal cord is exposed. Ifthe vertebrae (bones of the spinal column) surrounding the spinal
cord do not close properly during the first 28 days after
fertilization, the cord or spinal fluid bulge through, usually in the
lower back.
Anencephaly is the severe underdevelopment of the brain.What foods contain folic acid?
Approximately half of all pregnancies are unplanned, so the U.S. Food
and Drug Administration has taken steps to fortify certain foods so that
all women of childbearing age get a daily dose of folic acid. The
following foods can help you obtain your recommended amount of folic
acid:
Leafy green vegetables, such as a large spinach salad Citrus fruits, such as orange juice Beans Breads
Cereals Rice Pastas
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A daily vitamin with folic acid may be suggested by your health care
provider since the food listed above may not contain enough folic acid
to meet the daily requirement.
How do I know if I am at risk for having a baby with neural defects, and
how can I prevent this from happening?
Women who are at greatest risk are those that have had a previous
pregnancy that involved a neural defect. Women who are not eating a
balanced diet that includes folic acid are also at risk.
The best way to prevent neural defects is to take the recommended
400 micrograms of folic acid daily for one month before conception and
during the first three months of pregnancy. Multivitamins that include
folic acid should only be used as a supplement under the care of your
health care provider.
8.Why you need iron during pregnancyEven before you're pregnant, your body needs iron for several reasons:
It's essential for making hemoglobin, the protein in red blood cellsthat carries oxygen to other cells.
It's an important component of myoglobin (a protein that helpssupply oxygen to your muscles), collagen (a protein in bone,
cartilage, and other connective tissue), and many enzymes.
It helps you maintain a healthy immune system.But during pregnancy you need a lot more of this crucial mineral. Here's
why:
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The amount of blood in your body increases during pregnancyuntil you have almost 50 percent more blood than usual, so you
need more iron to make more hemoglobin.
You need extra iron for your growing baby and placenta,especially in the second and third trimesters.
Many women need more because they start their pregnancy withinsufficient stores of iron.
Iron-deficiency anemia during pregnancy is associatedwithpreterm delivery, low birth weight, and infant mortality.
How much iron you need
Pregnant women: 27 milligrams (mg) of iron per day
Non-pregnant women: 18 mg
You don't have to get the recommended amount of iron every day.
Instead, aim for that amount as an average over the course of a few
days or a week.
Food sources of iron
Red meat is one of the best sources of iron for pregnant women. (Liver
provides the highest concentration of iron, but because it contains
unsafe amounts ofvitamin A, it's best avoided during pregnancy.) If
your diet doesn't include animal protein, you can get iron from
legumes, vegetables, and grains.
There are two forms of iron: non-heme iron, which is found in plants (as
well as in meat, poultry, and fish), and heme iron, which is found only in
animal products. Heme iron is easier for your body to absorb. (Iron-
http://www.babycenter.com/0_preterm-labor-and-birth_1055.bchttp://www.babycenter.com/0_preterm-labor-and-birth_1055.bchttp://www.babycenter.com/0_preterm-labor-and-birth_1055.bchttp://www.babycenter.com/0_vitamin-a-in-your-pregnancy-diet_675.bchttp://www.babycenter.com/0_vitamin-a-in-your-pregnancy-diet_675.bchttp://www.babycenter.com/0_vitamin-a-in-your-pregnancy-diet_675.bchttp://www.babycenter.com/0_vitamin-a-in-your-pregnancy-diet_675.bchttp://www.babycenter.com/0_preterm-labor-and-birth_1055.bc7/29/2019 Biochemistry Assignement.
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fortified foods and supplements provide non-heme iron.) To make sure
you're getting enough, eat a variety of iron-rich foods every day.
Common sources of heme iron:
Red meat, poultry, and fish are all good sources of heme iron. (For easy
reference, 3 ounces of meat is about the size of a deck of cards.)
3 ounces lean beef chuck: 3.2 mg 3 ounces lean beef tenderloin: 3.0 mg 3 ounces roast turkey, dark meat: 2.0 mg 3 ounces roast turkey breast: 1.4 mg 3 ounces roast chicken, dark meat: 1.1 mg 3 ounces roast chicken breast: 1.1 mg 3 ounces halibut: 0.9 mg
3 ounces pork loin: 0.8 mg
Common sources of non-heme iron:
1 cup iron-fortified ready-to-eat cereal: 24 mg 1 cup fortified instant oatmeal: 10 mg 1 cup edamame (boiled soybeans): 8.8 mg 1 cup cooked lentils: 6.6 mg 1 cup cooked kidney beans: 5.2 mg
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1 cup chickpeas: 4.8 mg 1 cup lima beans: 4.5 mg
1 ounce roasted pumpkin seeds: 4.2 mg
1 cup cooked black or pinto beans: 3.6 mg 1 tablespoon blackstrap molasses: 3.5 mg 1/2 cup raw firm tofu: 3.4 mg 1/2 cup boiled spinach: 3.2 mg 1 cup prune juice: 3.0 mg 1 slice whole wheat or enriched white bread: 0.9 mg 1/4 cup raisins: 0.75 mg
9.Protein requirements in pregnancy rise to 1.1 g/kg/day (71 g),amounting to more than a 50% increase in protein intake to allow for
fetal growth and milk production. The source of protein may be asimportant as the quantity, however. Some evidence suggests that
protein requirements can be more safely met by vegetable than by
animal protein. Meat is a major source of saturated fat and cholesterol;
it is also a common source of ingestible pathogens29
and a rich source
of arachidonic acid, a precursor of the immunosuppressive eicosanoid
PGE2.
Pregnant women also should not meet their increased need for protein
by the intake of certain types of fish, such as shark, swordfish,
mackerel, and tilefish, which often contain high levels of
methylmercury, a potent human neurotoxin that readily crosses the
placenta.30 Other mercurycontaminated fish, including tuna and fish
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taken from polluted waters (pike, walleye, and bass), should be
especially avoided.31
There is no nutritional requirement for fish or fish
oils. Vegetable protein sources, aside from meeting protein needs, can
help meet the increased needs for folate, potassium, and magnesiumand provide fiber, which can help reduce the constipation that is a
common complaint during pregnancy.
roteins
Proteins, from the Greekproteiosmeaning first, are important
biological molecules (biomolecules) that consist of strings of smaller
units called amino acids, the building blocks of proteins. These aminoacids are linked together in sequence as polypeptide chains that fold
into compact shapes. Proteins vary in
The three functions of macronutrients
Provide energy Promote growth and
development
Regulate body
functions
Carbohydrates Proteins Proteins
Poteins Lipids Lipids
Lipids (fats and
oils)
Vitamins Vitamins
Minerals Minerals
Water Water
(Illustration by GGS Information Services/Thomson Gale.)
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shape and size, some consisting only of ^20-30 amino acids and others
of several thousands. They are present in every living cell. In the skin,
hair, callus, cartilage, muscles, tendons and ligaments, proteins hold
together, protect, and provide structure to the body. As enzymes,hormones, antibodies, and globulins, they catalyze, regulate, and
protect the body chemistry. Important biomolecules like hemoglobin,
myoglobin and various lipoproteins, that carry oxygen and other
substances within the body are also proteins.
Besides providing energy to the body, dietary protein is also required
for growthespecially by children, teenagers, and pregnant women,
tissue repair, immune system function, hormone and enzyme
production, and for lean muscle mass and tone maintenance. When
eaten, the proteins contained in foods are broken down into amino
acids, an important dietary source of nitrogen. To make the proteins
that it needs (protein biosynthesis), the body also needs them. There
are 20 amino acids and the body can make some of them from
components within the body, but it cannot synthesize nine of them,accordingly called the essential amino acids since they must be
provided in the diet. They include: histidine, isoleucine, leucine,
methionine, phenylalanine, threonine, tryptophan, and valine. Protein
that comes from animal sources are called complete proteins
because they contains all of the essential amino acids while protein
from plants, legumes, grains, nuts, seeds and vegetables are called
incomplete proteins because they are lacking one or more essentialamino acid(s).
Proteins are complex molecules and the body needs time to break
them down. This is why they are a slower and longer-lasting source of
energy than carbohydrates. According to the Dietary Reference Intakes
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(RDI)published by the Unites States Department of Agriculture (USDA),
adults need to eat about 60 grams of protein per day (0.8 g per kg of
weight). Adults who are physically very active or trying to build muscle
need slightly more. Children also need more. If more protein isconsumed than is needed, the body stores its components as fat, which
can be broken down and used for energy as need arises. Proteins are
broken down during digestion, which exposes them to acid in the
stomach and to degradation by the action of enzymes called proteases.
Some ingested amino acids are converted to carbohydrates
(gluconeogene-sis), which is also used under starvation conditions to
generate glucose from the bodys own proteins, particularly those
found in muscle.
Carbohydrates
There are two basic types of carbohydrates, depending on their size.
Simple carbohydrates (mono-sachharides) are those that cannot be
broken down into simpler sugars. They include various forms of sugar,
such as glucose and fructose. Complex carbohydrates are larger and
consist of long strings of simple carbohydrates (disachharides,
oligosachharides, poly-sachharides). They include sucrose, lactose,
maltose, maltodextrins, fructo-oligo-saccharides, starch, amy-lose, and
amylopectin. The human body uses carbohydrates in the form of
glucose and it can convert both simple and complex carbohydrates into
energy very quickly. The brain needs to use glucose as an energy
source, since it cannot use fat for this purpose. This is why the level of
glucose in the blood must be constantly maintained above the
minimum level. The body also stores very small amounts of excess
carbohydrate as energy reserve. The liver stores some as glycogen, a
complex carbohydrate that the body can easily and rapidly convert to
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energy. Muscles also store glycogen, which they use during periods of
intense physical activity. The amount of carbohydrates stored as
glycogen is equivalent to about a days worth of calories. A few other
body tissues store carbohydrates as complex carbohydrates that cannotbe used to provide energy.
Carbohydrates have two major roles: they are the primary energy
source for the brain and they are a source of calories to maintain body
weight. A diet containing an optimum level of carbohydrates may help
prevent body fat accumulation. They are also involved in the
construction of the body organs and nerve cells, and in the definition of
a persons biological identity such as their blood group. Dietary fiber,
which is a carbohydrate, also helps keep the bowel functioning
properly. Because they are smaller, simple carbohydrates can be
broken down by the body more quickly and they are the fastest source
of energy. Fruits, dairy products, honey, and maple syrup contain large
amounts of simple carbohydrates, which provide the sweet taste in
most candies and cakes.
carbohydrates occur in a wide variety of foods. For example, table
sugar (sucrose) is a combination of the glucose and fructose that occurs
naturally in sugar beet, sugar cane and fruits. Lactose is the main sugar
in milk and dairy products and maltose is a sugar occurring in malt.
Another type of carbohydrate are the polyols, the so-called sugar
alcohols. They do occur naturally but most are made commercially by
the transformation of sugars. Complex carbohydrates also include
starch, the main energy reserve in root vegetables and cereals. Non-
starch carbohydrates are the main components of dietary fiber. These
are the indigestible portion of plant foods, such as cellulose, the major
component of plant cell walls that consists of several thousand glucose
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units. Simple sugars are absorbed directly by the small intestine into
the bloodstream, where they are then transported to where they are
required. Complex carbohydrates are broken down by enzymes into
their constituent sugars which are then absorbed into the bloodstreamwhile dietary fiber moves food through the digestive system.
Fats
Besides being a source of energy, fat stores protect the internal organs
of the body. Some essential fats are also required for the formation of
hormones. Fats are the slowest source of energy but the most energy-
efficient form of food. Each gram of fat supplies the body with about 9calories, more than twice
that supplied by the two other macronutrients. Because fats are such
an efficient form of energy, they are stored by the body either in the
abdomen (omental fat) or under the skin (subcutaneous fat) for use
when the body needs more energy. Fats that are in foods are
combinations of four main types:
Saturated fats: These fats consist of fatty acid chains that have nodouble bonds between the carbon atoms of the chain. They are
called saturated because they are fully saturated with hydrogen
atoms and cannot incorporate more. They are solid at room
temperature and are most often of animal origin. Examples are
butter, cheese, and lard. These fats provide a concentrated source
of energy in the diet and building blocks for cell membranes and a
variety of hormones and hormone-like substances. An excess of
these fats in the diet however, is believed to raise the cholesterol
level in the bloodstream.
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Monounsaturated fats: These are composed mostly ofmonounsaturated fatty acids, meaning molecules with one
double-bonded carbon, with all the others carbons being single-
bonded. They are liquid at room temperature. Examples are olive,peanut and canola oil. They appear to protect against heart
disease, in that they reduce blood cholesterol levels.
Polyunsaturated fats: These fats are composed mostly of fattyacids such as linoleic or linolenic acids which have two or more
double bonds in each molecule, as for example corn oil and
safflower oil. They are also liquid at room temperature and can be
further divided into the omega-6 and the omega-3 families.
Polyunsaturated fats are thought to reduce the risk of coronary
heart disease. The omega-3 forms are believed to have a positive
impact on heart health and to play an important role in brain and
eye function. Oily fish such as salmon, herring and mackerel are
examples of omega-3s, and they are also found in walnuts and
some oils like soybean and rapeseed.
Trans fatty acids. Unsaturated fats come in different chemicalstructures: a bent cis form or a straight trans form. When they
adopt the trans form, they are called transfatty acids. They are
produced by the partial hydrogenation of vegetable oils and
present in hardened vegetable oils, most margarines, commercial
baked foods, and many fried foods. An excess of these fats in the
diet is thought to increase the risk of heart disease.
Description
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The three types of macronutrients do not have the same chemical
composition. When compared with carbohydrates and fats, proteins
are very different.
Fats largely consist of hydrocarbon chains, containing 75-85% carbon.
Carbohydrates are roughly 50% oxygen, and like fats, they usually have
less than 5% nitrogen or none at all. Proteins, on the other hand,
consist of 15-25% nitrogen and about an equal amount of oxygen. The
three macronutrients are often found together in most foods, but in
varying amounts, or alone in other foods. The Nutrition Facts labels
provide a breakdown of the macronutrient composition of various
foods.
Proteins
According to RDI, between 10 and 35% of calories should come from
protein.
Foods that are a source of protein include:
Animal protein: Meat, poultry, fish, eggs, milk, cheese and yogurtprovide high biological value proteins, because they contains all
the essential amino acids.
Plant proteins: Plants, legumes, grains, nuts, seeds and vegetablesprovide low biological value proteins. However, combining
proteins from different plant sources in the same meal often
results in a mixture of higher biological value. Examples of such
combinations are: beans with rice, pasta or manioc, chickpeas
with bread, lentils with potatoes, vegetables with cereals.
Carbohydrates
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According to the RDI, between 50 and 55% of calories should come
from carbohydrates and 20-35 g dietary fiber per day should be taken
by all those over two years of age.
Sources of dietary carbohydrates include:
Monosaccharides: fruits, berries, vegetables and honey. Disaccharides: table sugar, sugar beet, sugar cane and fruits. Polyols: Isomalt Oligosaccharides: grains and vegetables Starch polysaccharides: cereals, whole grains, rice, pasta,
potatoes, peas, corn and legumes.
Non-starch polysaccharides: dietary fiber such as cellulose,hemicelluloses, pectins and gums.
Fats
Sources of dietary fats include:
Saturated: Butter, cheese, meat, meat products (sausages,hamburgers), whole milk and yoghurt, pies, pastries, lard,
dripping, hard margarines and baking fats, coconut and palm oil.
Monounsaturated: Olives, rapeseed, nuts (pistachio, almonds,hazelnuts, macadamia, cashew, pecan), peanuts, avocados, and
their oils.
Omega-3 polyunsaturated: Salmon, mackerel, herring, trout(particularly rich in the long chain omega-3 fatty acids EPA or
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eicosapentaenoic acid and DHA or docosahexaenoic acid),
walnuts, rape-seed, soybean flax seed, and their oils.
Omega-6 polyunsaturated: Sunflower seeds, wheat germ, sesame,walnuts, soybean, corn and their oils. Certain margarines
Trans fatty acids: Some frying and baking fats (hydrogenatedvegetable oils) used in biscuits, cakes and pastries, dairy products,
fatty meat from beef and sheep.