This Slide share includes Carbohydrate and its Nutrition. It includes introduction, classification, digestion and absorption, sources, RDA and effects of excess and limited use of carbs and fibre and its health effects.

1. MRS.NAGAMANI.T
Q U A L I T Y H E AL TH C A RE C O L L EGE O F N U RSI NG
D E P T . O F C O M M UNI T Y H EA L T H N UR S I NG
CARBOHYDRATES

2. Introduction:
Carbohydrates are
* a major source of energy from our diet.
* composed of the elements C, H and O.
* also called saccharides, which means “sugars.”
* are produced by photosynthesis in plants.
* such as glucose are synthesized in plants from CO2,
H2O, and energy from the sun.
* are oxidized in living cells to produce CO2, H2O, and
energy.

3.  Carbohydrates are sugars and provide energy
when consumed.
 Our bodies break down carbohydrates to extract
energy. Carbon dioxide and water are released in
the process.
 Glucose is the primary carbohydrate our bodies use
to produce energy.
 Carbohydrates are classified as biomolecules.
 Simple carbohydrates are referred to as
 simple sugars and are often sweet to the taste.
 Consumption of more sugar than is needed for
energy results in conversion of these sugars to fat.
 Complex carbohydrates include starches and the
plant and wood fibers known as cellulose.

4. Introduction to Carbohydrates, Continued
• Carbohydrates are found on the surface of cells
where they act as “road signs” allowing
molecules to distinguish one cell from another.
• ABO blood markers found on red blood cells
are made up of carbohydrates. They allow us to
distinguish our body’s blood type from a foreign
blood type.
• Carbohydrates in our body prevent blood clots.
They are also found in our genetic material.

5. • Carbohydrates also can combine with lipids to form glycolipids
 OR
• With proteins to form glycoproteins.

6. Classification of Carbohydrates
• Monosaccharides are the simplest carbohydrates. They
cannot be broken down to smaller carbohydrates.
• Disaccharides consist of two monosaccharide units joined
together; they can be split into two monosaccharides.
Sucrose, table sugar, can be broken down into glucose and
fructose.
• Oligosaccharides contain anywhere from three to nine
monosaccharide units. ABO blood groups are
oligosaccharides.
• Polysaccharides are large molecules containing 10 or more
monosaccharide units. Carbohydrate units are connected in
one continuous chain or the chain can be branched.

7. Monosaccharide
One Sugar Unit
Important Single Sugar are Glucose, Fructose,
Galactose
Glucose (Dextrose):
• Give Energy for bodyActivity
• It is primaryFuel of Cell
• It usuallynot found in Diet (Corn Syrup)
• Produce from Starch.

8. Monosaccharide
Fructose:
• Fruit, Honey
• Sweetest of Simple Sugar
• Soft drink, Ready to use Cereals,
Desserts
Galactose:
• MilkSugar

9. Monosaccharides;
Some Important Monosaccharides
• Glucose is the most abundant monosaccharide found in
nature. Glucose is also known as dextrose, blood sugar,
and grape sugar.
• Glucose is broken down in cells to produce energy.
• Diabetics have difficulty getting glucose in their cells,
which is why they must monitor their blood glucose levels
regularly.
• Galactose is found combined with glucose in the
disaccharide lactose, which is present in milk and other
dairy products.
• Mannose, a monosaccharide, is found in some fruits and
vegetables.
• Cranberries contain high amounts of mannose, which has
been shown to be effective in urinary tract infections.

10. Monosaccharides,Continued
• Fructose commonly referred to as fruit sugar
or levulose.
• Fructose is combined with glucose to give
sucrose, or table sugar.
• Fructose is the sweetest monosaccharide and
is found in fruits, vegetables, and honey.
• Fructose can be broken down for energy in the
body.

11. • Benedict’s test is a useful test to determine
the presence of an oxidation reaction that
occurs with sugars.
• Benedict’s test can be used in urine dipsticks to
determine the level of glucose in urine. Excess
glucose in urine suggests high levels of glucose
in blood, which is an indicator of diabetes.

12. Characteristicsof Monosaccharide
• Are Simple Single Sugar
• Which require no Digestion
• Quicklyabsorbed from Intestine
to Blood and carried to the Liver
• In Liver Converted into Glycogen
and stored.
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13. 37
Disaccharides
• Disaccharides consist of two monosaccharide units
joined together;
• they can be split into two monosaccharides.
Eg;
• Maltose
• Lactose
• Sucrose

14. Disaccharides
• Are Simple Double Sugar
• Which Link with two Single Sugar
• Important Disaccharides are
Sucrose, Lactose &Maltose
 Sucrose = Glucose + Fructose
e.g. Sugar, Brown Sugar
Sugarcane, Sugar beet.
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15. DisaccharideS
 Lactose = Glucose +
Galactose
e.g. Milk Sugar
Lactose is less soluble
LessSweet than Sucrose
 Maltose = Glucose + Glucose
Starch=> Maltose => Glucose
Sugar alcohols such Sorbitol
Used in Candies, Beverages.

16. Maltose
• Maltose is known as malt sugar.
• It is formed by the breakdown of starch.
• Malted barley, a key ingredient in beer,
contains high levels of maltose.
• During germination of barley seeds, the starch
goes through hydrolysis to form maltose. This
process is halted by drying and roasting
barley seeds prior to their germination.
Disaccharides,Continued

17. Disaccharides,Continued
Lactose
• Lactose is known as milk sugar.
• It is found in milk and milk products.
• An intolerance to lactose can occur in people
who inherit or lose the ability to produce the
enzyme lactase that hydrolyzes lactose into
its monosaccharide units.

18. Disaccharides,Continued
Sucrose
• Sucrose is known as table sugar.
• It is the most abundant disaccharide found in
nature.
• Sucrose is found in sugar cane and sugar
beets.

19. OLIGO SACCHARIDES
 Oligosaccharides are a type of carbohydrate
formed when three to 10 simple sugars are linked
together.
 
Small amounts occur naturally in many plants.
 Oligosaccharides can have many functions
including cell recognition and cell binding.
 For example, glycolipids have an important role in
the immune response.
 Eg; maltodextrins or cellodextrins,

20.  ABO Blood Types
• ABO blood types refer to carbohydrates on red
blood cells.
 These chemical markers are oligosaccharides that
contain either three or four sugar units.

21. Polysaccharides
 Polysaccharides are large molecules of
monosaccharides that are connected to each other
through their anomeric carbons. There are two types
of polysaccharides:
1. Storage polysaccharides contain only  -glucose
units. Three important ones are starch, glycogen,
and amylopectin.
2. Structural polysaccharides contain only -glucose
units. Two important ones are cellulose and chitin.
Chitin contains a modified -glucose unit.

22. Polysaccharides
⚫Starch = (Glucose)n
e.g. Cereals, Legumes,Tubers
⚫Glycogen = (Glucose)n
Animal Food
Stored in Liver &Muscles
⚫Fiber :
Plant food –V
egetable, Fruits,Grains
Not digested byHuman
e.g.Cellulose, Hemicellulose, Pectins,Gums,
Lignin.
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23. Amylose and amylopectin—starch
• Starch is a mixture of amylose and amylopectin
and is found in plant foods.
• Amylose makes up 20% of plant starch.
• Long chains of amylose tend to coil.
• Amylopectin makes up 80% of plant starch.
• During fruit ripening, starch undergoes
hydrolysis to produce glucose and maltose,
which are sweet.
• When we consume starch, our digestive system
breaks it down into glucose units for use by our
bodies.
Polysaccharides, Continued

24. Polysaccharides, Continued
Glycogen
• Glycogen is a storage polysaccharide found in
animals.
• Glycogen is stored in the liver and muscles.
• When glucose is needed, glycogen is
hydrolyzed in the liver to glucose.

25. Glycogen
Glycogen
• is the polysaccharide that
stores glucose in muscle.
• is similar to amylopectin,
but is more highly
branched.

26. Polysaccharides, Continued
Cellulose
• Cellulose contains glucose units bonded
• This glycosidic bond configuration changes the
three-dimensional shape of cellulose compared
with that of amylose.
• The chain of glucose units is straight. This
allows chains to align next to each other to form
a strong rigid structure.

27. Heparin
• Heparin is a medically important polysaccharide
because it prevents clotting in the bloodstream.
• It belongs to a group of polysaccharides called
glycosaminoglycans.

28. Sources of Carbohydrates
Sugar :
Honey
, Fruits, Soft Drink, Milk, Sugar,
Starch:
Cereals, Pasta, Flour, Bread, Potatoes, RootV
ege.,
Pulses
Fiber: Cereals, Bran, Outer skin of Fruits
& V
ege., Brown rice, Oatmeals
Pectin: Fruits.

29. Sourcesof Carbohydrates
Carbohydrates Food Source
Glucose Fruits, Honey, Corn Syrup
Fructose Fruits, Honey
Galactose Milk
Maltose Backed Starch
Sucrose Cane & Beat Sugar
Lactose Milk Product
Starch & Dextrin Grains, Root &Tubers, Legumes
Glycogen Meat Product, Sea Food
Cellulose V
egetables, Outer coat of Seed
Pectin&Gum
Fruits, Plant Secretion, seeds.

30. Functionof Carbohydrates
Energy Supply. Brain, Cell
Spare Proteins
Synthesis of Substances
Non-essentialAmino acids
Glycoproteins
Glycolipids
Promote complete lipid metabolism
Provide Bulk Fiber in the Diet.

31. Functionof Carbohydrates
 Energy Supplyfor body function
 Essential for the Oxidation of Fats
 Proteinssparing action
 Provide Carbon for synthesis of Non-essentialAmino acids
 Are present in some tissue Constituents
 Add flavour to Diet
 Nucleicacid of Connective tissue Matrix, Galactosides of Nerve
Tissue
 Necessaryfor proper functioning of CNS
 Adequate hepatic Glycogen Storage enhances normal liver
detoxification ability
.

32. RDA of Carbohydrates
 Carbs are a concentrated source of calories, at 4
calories per gram.
 The Dietary Guidelines recommends that
carbohydrates make up 45 to 65 percent of total
daily calories.
 So, if you get 2,000 calories a day, between 900
and 1,300 calories should be from carbohydrates.
That translates to between 225 and 325 grams of
carbohydrates a day.

34. DIGESTION AND ABSORPTION OF
CARBOHYDRATES
 Digestion : Process of breaking down of food into
simpler compounds

35.  Mechanical Digestion
⦁ Chewing, also known as mastication, crumbles the carbohydrate
foods into smaller and smaller pieces to form bolus.
 Chemical Digestion
⦁ Salivary glands in oral cavity secrets saliva.
⦁ Saliva contains enzyme salivary amylase/ptyalin.
⦁ Salivary amylase hydrolyses starch into maltose and dextrin at pH
of 6.8 to 7.
⦁ Only about 5% starch are broken down in mouth.

36.  Mechanical Digestion
⦁ The strong peristaltic contractions of the stomach mix the carbohydrates
into the more uniform mixture of chyme.
 Chemical Digestion
⦁ The action of ptyalin continues only inside bolus.
⦁ About 30-40% of dietary starch is digested before bolus is broken down
and acidified.
⦁ The action of ptyalin is blocked by acidic nature of stomach(pH 1.5).
⦁ Further breakdown of carbohydrates takes place when the chyme is passed
down to the small intestine.

37.  Mechanical Digestion
⦁ There is no mechanical digestion in small intestine.
 Chemical Digestion
⦁ The pancreas releases pancreatic juice through a duct.
⦁ Pancreatic juice contains the enzyme, pancreatic amylase.
⦁ Enzymes are also secreted by the intestinal cells that line the
villi.

38. Hydrolyze oligo- and polysaccharides into
monosaccharide as follow:
o Starch pancreatic amylase Maltose + Isomaltose
maltase
o Maltose Glucose +Glucose
o Isomaltose isomaltase Glucose + Dextrin
o Dextrin
o Sucrose
o Lactose
dextrinase Glucose
sucrase Glucose + Fructose
lactase Glucose + Galactose

39.  Certain carbohydrate like cellulose are undigested by
human due to lack of enzymes like cellulase.
 But ,it provides fibers for absorption of water into the large
intestine ,expand the muscle walls and trigger the muscle
contractions for egestion.
 Cure for constipation.

40. o Digested food
from alimentary
canal to blood
stream.
o Monosaccharide is
absorbed in small intestine.
o Sodium Glucose Transport
Protein(SGLT) in
membrane helps absorb
glucose and galactose.
o Fructose absorbed is
converted to glucose
inside cell.

42. DIETARY FIBRE
 Dietary fiber, also known as roughage or bulk,
includes the parts of plant foods body can't digest or
absorb.
 Dietary fiber — found mainly in fruits, vegetables,
whole grains and legumes — is probably best known
for its ability to prevent or relieve constipation.
 Fiber is simply a type of carbohydrate found
naturally in plant-based foods that is not digestible
in humans.

43.  Fiber is commonly classified as soluble, which dissolves
in water, or insoluble, which doesn't dissolve.
 Soluble fiber. This type of fiber dissolves in water to
form a gel-like material. It can help lower blood
cholesterol and glucose levels. Soluble fiber is found in
oats, peas, beans, apples, citrus fruits, carrots, barley and
psyllium.
 Insoluble fiber. This type of fiber promotes the
movement of material through your digestive system and
increases stool bulk, so it can be of benefit to those who
struggle with constipation or irregular stools. Whole-
wheat flour, wheat bran, nuts, beans and vegetables, such
as cauliflower, green beans and potatoes, are good
sources of insoluble fiber.

44. Action of Fiber in the Body
Insoluble Fiber
• Accelerate GITransit
• Increase FecalW
eight
• Promotes bowel
movement
• Slow Starch
Hydrolysis
• DelaysGlucose
Absorption.
Soluble Fiber
• DelaysGITransit
• Lowersblood
Cholesterols
• DelaysGlucose
absorption.
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45. Health benefits of fiber;
 Lowers cholesterol: Soluble fiber has been shown to lower
cholesterol by binding to bile (composed of cholesterol) and taking
it out of the body. This may help reduce the risk of heart disease.
 Better regulates blood sugar levels: A high-fiber meal slows
down the digestion of food into the intestines, which may help to
keep blood sugars from rising rapidly.
 Weight control: A high-fiber diet may help keep you fuller
longer, which prevents overeating and hunger between meals.
 May prevent intestinal cancer: Insoluble fiber increases the
bulk and speed of food moving through the intestinal tract, which
reduces time for harmful substances to build up.
 Constipation: Constipation can often be relieved by increasing
the fiber or roughage in your diet. Fiber works to help regulate
bowel movements by pulling water into the colon to produce
softer, bulkier stools. This action helps to promote better
regularity.

46. Effects of excess intake of carbohydrates
 Excess carbohydrate intake places a large
metabolic load on the body. When the body
constantly has high levels of blood sugars to deal
with over time, this leads to weight gain, poor
metabolic health and an increased risk of heart
disease.
 If habitually overeating carbohydrates, the excess
calories could lead to weight gain. This is especially
true of sugars and refined carbs, like white flour,
since they don't tend to fill up despite their high
calorie count.

47. Type 2 Diabetes
 Consuming too many carbs, especially those with a
high glycemic load, can increase the risk of several
disorders, including Type 2 diabetes.
 After consuming a carbohydrate-containing meal the
blood sugar increases, pancreas releases insulin,
which helps convert glucose into a storage
compound in the liver, muscles and other tissues.
This eventually lowers the blood sugar. Type 2
diabetes develops when the body stops making
insulin or become insensitive to it.

48. Cardiovascular Disease
 A diet containing too many carbohydrates can raise
the blood level of triglycerides, a type of unhealthy
fat that travels in the blood. It can also lower the
blood levels of high-density lipoprotein, often
referred to as good cholesterol.

49. The glycemic index
 The glycemic index (GI) ranks how quickly a food raises
blood sugar levels on a scale of 0 to 100.
 Foods with a high GI cause rapid spikes in blood sugar.
Foods with a low GI take longer for the body to digest,
leading to more balanced blood sugar levels.
 Eating lots of foods with a high GI may increase a
person’s risk for type 2 diabetes and other health
concerns, including heart disease and overweight.
 A diet with plenty of low GI foods, together with exercise
and regular sleep, can help a person maintain health and
a moderate weight.

50.  To follow a low GI diet, a person can eat more
unrefined foods, such as:
 oats, barley, or bran
 whole-grain bread
 brown rice
 plenty of fresh fruit and vegetables
 fresh, whole fruit instead of juice
 whole-grain pasta
 salads and raw vegetables

51. Effects of low intake of carbohydrates
 Complications such as heart arrhythmias, cardiac
contractile function impairment, sudden death,
osteoporosis, kidney damage, increased cancer risk,
impairment of physical activity and lipid
abnormalities can all be linked to long-term
restriction of carbohydrates in the diet.

52. Thank you