Nutrients
are sorted into categories on the basis of their chemical structures and
functions. Carbohydrates, proteins,and fats contained in foods are known as the
macronutrients, because they are required in the largest quantities. In addition
to their other functions, macronutrients provide energy in the form of calories.
Vitamins and minerals are known as the micro nutrients. They are required by
your body in much smaller quantities. Although the micronutrients help your
body use the energy in macronutrients, they provide no energy(calories)
themselves. Water is also an essential, calorie- free nutrient. The work our
bodies do each day causes us to deplete some of our stores of these essential
nutrients. Only by maintaining a diet that is rich in various nutrient-containing
foods can we replace those lost nutrients.
Each
of the macronutrients—carbohydrates, proteins, and fats—plays
various roles in the function of our bodies. In addition to their unique
functions, all of the macronutrients supply calories. When we eat more protein,
carbohydrate, or fat than we need to replenish what we have used, the excess is
converted to and stored as fat. Calories are used to support all muscular activity,
to carry out the metabolic reactions that sustain the body, to maintain body temperature,
and to support growth. But when we consistently take in more calories than we
use, we gain weight.Weight is maintained when energy (calorie) intake
balances energy output.
CARBOHYDRATES
The
carbohydrates are a vast and diverse group of nutrients found in most foods. This
group includes simple sugars (like the sugar you add to your morning tea and
coffee) and complex forms such as starches (contained in pasta, bread, cereal, and
in some fruits and vegetables), which are broken down during digestion to produce
simple sugars. The main function of the simple sugars and starches in the foods
is to deliver calories for energy. The simple sugar glucose is required to
satisfy the energy needs of the brain, whereas our muscles use glucose for
short-period of great activity. The liver and muscles also convert small
amounts of the sugar and starch that we eat into a storage form called glycogen.
After a long workout, muscle glycogen stores must be replenished. Both simple
sugars and starches provide about 4 calories per gram. But health experts agree
that we should obtain most of our calories (about 60 percent) from carbohydrates.
Our individual requirements depend on age, sex, size, and activity level.
In
contrast to the other carbohydrates, fiber (a substance contained in bran,
fruits, vegetables, and legumes) is a type of complex carbohydrate that cannot
be readily digested by our bodies. Even though it isn’t digested, fiber is essential
to our health. Nutrition professionals recommend 25 to 30 grams of fiber daily.
Simple Sugars
Simple
sugars make foods sweet. They are small molecules found in many foods and in
many forms. Some simple sugars occur naturally in foods. For example, fructose
is the sugar that naturally gives some fruits their sweet flavor. Table sugar(The White Devil), the sugar that we spoon onto our
cereal and add to the cookies we bake, also called sucrose, is the most
familiar simple sugar (Processed Sugar).
A ring-shaped molecule of sucrose actually consists of a molecule of fructose
chemically linked to a molecule of another simple sugar called glucose. Sugars
such as fructose and glucose are known as monosaccharides, because of their
single (mono) ring structure, whereas two-ringed sugars such as sucrose are known
as disaccharides. Another disaccharide, lactose (The Sugar Which Found In
Milk), the sugar that gives milk its slightly sweet taste, consists of glucose
linked to yet another simple sugar called galactose. The inability to digest lactose
to its constituent sugars is the cause of lactose intolerance, a condition
common to adults of Asian, Mediterranean, and Africans.
The
table sugar that we purchase is processed from sugar cane or sugar beets. As an
additive to many different types of prepared or processed foods, sucrose adds
nutritive value (in the form of calories only), flavor, texture, and structure,
while helping to retain moisture. Today, sucrose is most often used to sweeten
(non dietetic) carbonated beverages and fruit drinks (other than juice), candy,
pastries, cakes, cookies, and frozen desserts. One of the most commonly consumed
forms of sugar is called high-fructose corn syrup. High-fructose corn syrup is
also commonly used to sweeten sodas, fruit drinks (not juices), some ice
creams, and some manufactured pastries and cookies. Other forms of sucrose
include brown sugar, maple syrup, molasses, and turbinado (raw) sugar. We must completely
avoid the sucrose (The Processed Sugars) and keep more Focused in Fructose (The
Naturally Form of Sugars).
Complex Carbohydrates
Found
almost exclusively in foods of plant origin, complex carbohydrates are long chains
of molecules of the simple sugar glucose. The complex carbohydrates in plant
foods can be divided into two groups: starch and fiber. Starch is the form of
carbohydrate that is found in grains, some fruits and vegetables, legumes,
nuts, and seeds. It provides energy for newly sprouting plants. Fiber is the tougher
material that forms the coat of a seed and other structural components of the plant.
Starches are digested by our bodies into their constituent glucose molecules
and used for energy, whereas fiber is not. Starch, like simple sugars, provides
4 calories per gram, whereas fiber (sometimes called non-nutritive fiber) provides
no calories. Like simple sugars, the role of starches in our diets is mainly to
provide energy.Fiber is actually a family of substances found in
fruits,vegetables, legumes, and the outer layers of grains. Scientists divide
fiber into two categories: those that do not dissolve in water (insoluble fiber)
and those that do (soluble fiber). Insoluble fiber, also called roughage,
includes cellulose, hemicellulose, and lignin, found in vegetables, nuts, and some
cereal grains. Soluble fibers include pectin, found in fruits, and gums, found
in some grains and legumes.
Fiber-rich
diets, which include ample amounts of whole-grain foods, legumes, and fresh
vegetables and fruits, have been linked with a lower risk of several diseases. Nutrition
scientists are just beginning to understand the role of dietary fiber in maintaining
health. Fiber appears to sweep the digestive system free of unwanted substances
that could promote cancer and to maintain regularity and prevent disorders of
the digestive tract. Fiber also provides a sense of fullness that may help
reduce overeating and unwanted weight gain. Diets that are rich in fiber and complex
carbohydrates have been associated with lower LDL cholesterol and a lower risk
for high blood pressure, coronary artery disease, and some types of cancer.
Fiber also help in keep your stomach full, it mainly helps when you are in fat
loss program. It’s also help in bowl movement.
PLANT
FIBERS: INSOLUBLE AND SOLUBLE
Insoluble Fiber—also known as roughage
These
fibers hold onto water, add bulk, and promote movement through the intestine.
CELLULOSE HEMICELLULOSE LIGNIN
Whole-wheat
flour Bran Woody portions of plants:
Bran Whole grains such as stem of broccoli, carrots
Nuts Vegetables Wheat
Vegetables Fruits Fruits
with edible seeds, such as
Raspberries and strawberries.
Soluble Fiber—dissolves in water and becomes gummy
These
types of fibers can help lower blood cholesterol and blood glucose.
GUMS PECTIN
Oats Apples
Legumes
and dried beans Citrus fruits: oranges, grapefruits
Barley Carrots
PROTEIN
Protein
is an essential part of our diets. Proteins are large, complex molecules resembling
tangled strings of beads. Each of the “beads” on the string is one of a group
of smaller molecules called amino acids. Amino acids are composed of carbon,
oxygen, hydrogen, and nitrogen, and some contain sulfur. Using the amino acids
from the protein you eat, the body makes more than 50,000 different proteins.
These proteins are the main structural elements of our skin, hair, nails, cell
membranes, muscles, and connective tissue. Collagen, the main protein in our
skin, provides a barrier to the invasion of foreign substances. Proteins in
cell membranes determine what substances can enter and exit cells. Our muscles,
which contain some 65 percent of the body’s total protein, give our bodies
their shape and strength.
Proteins in connective tissues such as tendons,
ligaments, and cartilage enable our skeletons to function, form internal organs,
and hold the organs in place. Proteins in the blood carry oxygen to all cells
and remove carbon dioxide and other waste products. The proteins in muscle, connective
tissue, and blood make up most of the protein in the body. Other proteins called
enzymes accelerate metabolic processes, and still other proteins and amino
acids are hormones and neuro chemicals, the substances that deliver signals
throughout the body and regulate all metabolic processes. During periods of
growth, our bodies must manufacture and store large amounts of protein.
Therefore, the requirement for protein in our diets is higher during growth. But
even when we are not growing, each of the unique proteins in the body has a
finite lifespan and must be replaced continuously. So the need for protein
never ends.
Dietary Protein and Body Protein
The
thousands of proteins that make up our bodies are assembled on demand from some
20 different amino acids. What are these amino acids, and where do they come
from? The protein from the meat we eat is not directly incorporated into our
muscles. The proteins in the foods we eat are digested first into small
“peptides.” Some of these peptides are further digested into their constituent amino
acids. Only amino acids and small peptides are actually absorbed by the small intestine
into the bloodstream. They are then delivered to the liver, muscles, brain, and
other organs, where they are used to make new proteins or converted to other
amino acids needed by those organs. Of the 20 amino acids that make up all
proteins, 9 are considered “essential” because they cannot be made in our bodies
and must be obtained from the foods we eat. Of the remaining 11, some are
essential for infants and persons with certain diseases. The rest of the amino
acids are considered “nonessential,” because our bodies can make them in
adequate amounts, if necessary. Nevertheless, they are easily supplied by
eating a well-balanced diet that includes a variety of foods. Most foods
contain protein. Some foods are better sources of protein than others.
“Complete” proteins are those that contain all the essential amino acids in
amounts needed to synthesize our body’s proteins. The best sources of complete
protein are lean meats and poultry, fish, low-fat dairy products, and eggs.
The
grains and cereals group of foods, which form the base of the Food Guide Pyramid,
are excellent sources of protein, but because these proteins often lack one or
more essential amino acids, they are called “incomplete” proteins. For example,
the proteins in corn are low in the essential amino acids lysine and tryptophan,
and wheat is low in lysine. In contrast, legumes tend to be rich in lysine but
a bit low in methionine. Among the legumes, soybeans contain the most complete
protein.What if we eat too little protein? Few Indian are at risk of eating too
little protein. However, individuals on severely restricted diets, those who
are unable to eat, and those whose needs are increased because of illness may
experience protein deficiency. To replenish the pools of essential amino acids
that have been depleted, in order to make critical proteins such as enzymes and
hormones, the body of a protein-deficient person begins to rob protein from
muscle by digesting that protein to its constituent amino acids. Because muscle
is needed for various vital functions, the loss of large amounts of muscle
protein can be fatal. Fortunately, the vast majority of people, even those who
engage in regular, rigorous endurance exercise, can easily meet their need for protein
by eating a balanced diet based on the Food Guide Pyramid.
Adequate
protein is critical for growth, metabolism, and health, but eating more protein
than we need will not build bigger muscles. Conversely, excess protein is
converted to fat. Foods of animal origin are high in protein but may also be
high in total and saturated fat. Lean meats and dairy products, fish, legumes,
and grains are the best sources of protein.
FATS
Fat
has a very bad image in Society. Because of people who only know one side of
its.
fat
and its connection with disease. Diets that are high in bad fat are strongly
associated with an increased prevalence of obesity and an increased risk of developing
coronary artery disease, high blood pressure, diabetes mellitus, and certain
types of cancer. Health authorities recommend that we reduce our total fat
intake to about 30 percent of total calories. They also recommend that we limit
our intake of saturated fat or Bad Fats (the type
of fat most often found in meat and dairy products) to less than 10 percent of
our fat calories and try to be sure that the fat we do eat is mostly the
monounsaturated or polyunsaturated type. These changes have been shown to decrease
our risk for several diseases.
Fat
as a Nutrient
Fat
is an essential nutrient, because our bodies require small amounts of several
fatty acids from foods (the so-called essential fatty acids) to build cell
membranes and to make several indispensable hormones, namely, the steroid hormones
testosterone, progesterone, and estrogen, and the hormone-like prostaglandins.
Dietary fats also permit one group of vitamins, the fat-soluble vitamins (A, D,
E, andK), to be absorbed from foods during the process of digestion. Fats help
these vitamins to be transported through the blood to their destinations. The
fat in our bodies also provides protective insulation and shock absorption for
vital organs. As a macronutrient, fat is a source of energy (calories). The fat
in food supplies about 9 calories per gram, more than twice the number of
calories as the same amount of protein or carbohydrate. As a result, high-fat
foods are considered “calorie-dense” energy sources. Any dietary fat that is
not used by the body for energy is stored in fat cells (adipocytes), the
constituents of fat (adipose) tissue. The Dietary Guidelines for recommend that
no more than 30 percent of our calories should come from fat, and only a third
of that should be saturated fat.
Sorting Out the
Fats
Our
health is influenced by both the amount and the type of fat that we eat. Fats
are molecules; they are classified according to the chemical structures of
their component parts. But you don’t need to be a chemist to understand the connection
between the various fats in foods and the effect these fats have on the risk
for disease. Some definitions will help. Dietary fats, or triglycerides, are
the fats in foods. They are molecules made of fatty acids (chain-like molecules
of carbon, hydrogen, and oxygen) linked in groups of three to a backbone called
glycerol. When we eat foods that contain fat, the fatty acids are separated
from their glycerol backbone during the process of digestion.
Fatty acids are either saturated or unsaturated, terms:
that
refer to the relative number of hydrogen atoms attached to a carbon chain. Fat
in the foods that we eat is made up of mixtures of fatty acids—some fats may be
mostly unsaturated, whereas others are mostly saturated. Monounsaturated fatty acids are fatty acids that lack one
pair of hydrogen atoms on their carbon chain. Foods rich in monounsaturated fatty
acids include canola, nut, and olive oils; they are liquid at room temperature.
A diet that provides the primary source of fat as monounsaturated fat (frequently
in the form of olive oil) and includes only small amounts of animal products
has been linked to a lower risk of coronary artery disease. This type of diet is
commonly eaten by people who live in the region surrounding the Mediterranean
Sea. Polyunsaturated fatty acids lack two or
more pairs of hydrogen atoms on their carbon chain. Safflower, sunflower, sesame,
corn, and soybean oil are among the sources of polyunsaturated fats (which are
also liquid at room temperature). The essential fatty acids, linoleic and linolenic
acid, are polyunsaturated fats. Like monounsaturated fats, polyunsaturated fats
lower blood cholesterol levels and are an acceptable substitute for saturated fats
in the diet.
Saturated fatty acids, or saturated fats, consist of fatty acids that are
“saturated” with hydrogen. These fats are found primarily in foods of animal
origin—meat, poultry, dairy products, and eggs—and in coconut, palm, andpalm
kernel oil (often called “tropical oils”). Foods that are high in saturated
fats are firm at room temperature.
Omega-3
fatty acids are a class of polyunsaturated fatty acids found in fish (tuna,
mackerel, and salmon, in particular) and some plant oils such as canola
(rapeseed) oil. These fatty acids have made the news because of the observation
that people who frequently eat fish appear to be at lower risk for coronary
artery disease. Omega-3 fatty acids also seem to play a role in your ability to
fight infection.
Hydrogenated
fats are the result of a process in which unsaturated fats are treated to make
them solid and more stable at room temperature. The hydrogenation process, which
involves the addition of hydrogen atoms, actually results in a saturated fat. Trans-fatty
acids are created by hydrogenation. An increase in consumption of these fats is
a concern because they have been associated with an increased risk of coronary
artery disease. Hydrogenated fat is a common ingredient in stick and tub
margarine, commercial baked goods, snack foods, and other processed foods.
Cholesterol
is a waxy, fat-like substance that is a necessary constituent of cell membranes
and serves as a precursor for bile acids (essential for digestion), vitamin D,
and an important group of hormones (the steroid hormones). Our livers can make
virtually all of the cholesterol needed for these essential functions. Dietary
cholesterol is found only in foods of animal origin, that is, meat, poultry,
milk, butter, cheese, and eggs. Foods of plant origin, that is, fruits,
vegetables, nuts, seeds, legumes, grains, and the oils derived from them, do
not contain cholesterol. Eggs are the food most often associated with
cholesterol, because the average large egg contains about 210 milligrams of
cholesterol (only in the yolk), and the recommended daily cholesterol intake is
300 mg or less. However, for most people, meat contributes a higher proportion
of cholesterol to the diet than do eggs, because cholesterol is found in both
the lean and fat portions.
“If You Guys Are In Fat Loss Program
Or Looking to Lose Fat Focus More on Healthy Fats. Because FAT KILLS FAT.”
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