Contains vital slides

1. TYPES OF NUTRIENTS
Mukabila-Chintu M

2. What are Nutrients?
 Are substances obtained from food and are
needed by the body
 Nutrients are classified as essential or
nonessential.
 Nonessential nutrients are manufactured in
the body and do not need to be obtained from
food
 Examples include cholesterol, a fatlike substance
present in all animal cells.

3. .
Conti….
Essential nutrients must be obtained from
food sources, because the body either
1. does not produce them or
2. produces them in amounts too small
to maintain growth and health.
 Essential nutrients include water,
carbohydrates, proteins, fats, vitamins, and
minerals.

4. Types of Essential Nutrients
Based on size
 Macro-nutrients-Carbohydrates, proteins, and fats
 micro-nutrients -Vitamins and minerals and water (vital
nutrient sustaining all life processes)
Based on how they are synthesized
 Organic nutrients- Carbohydrates, fats, proteins and
vitamins are organic nutrients/substances because plants
can synthesize them by the process of photosynthesis.
 Inorganic Nutrients- minerals that are extracted from
the soil by plants and in turn man obtain them from
plants or animals that has eaten the plants

5. Functions of nutrients
Human beings require food to
1. Grow
2. Reproduce
3. Maintain good health.
 Without food, our bodies could not stay
warm, build or repair tissue, or maintain a
heartbeat.

6. CARBOHYDRATES
 These are organic compounds of carbon, hydrogen and
oxygen (CHO). They are generally starches, sugars and
cellulose.
 SOURCES
Plants are the main source of carbohydrates in the human
diet
 Root tubers; irish potatoes, cassava, yam and carrots
 Fruits; banana, oranges, peaches
 Grains; maize, rice, wheat, groundnuts
 Stems; sugar cane
 Vegetables and milk are other sources.
Starch is a type of carbohydrates found in vegetable and
lactose from milk

7. CLASSIFICATION
 CHOs are classified into 3 groups
 Monosaccharide
 Disaccharide and
 Polysaccharides

8. Monosaccharide
 These are simplest form of carbohydrates and
often called simple sugars.
 These are the ones which are absorbed by the
body.
 These include glucose, fructose and galactose.
 Glucose; sources are grapes, sweet potatoes.
 It is the form in which sugar circulates in the blood
and oxidized to release energy.
 1 gram of carbohydrate is oxidised completely to give
4 calories.
 During metabolism all forms of other sugars are
converted to glucose

9.  Fructose-Is the sugar found in fruits and honey.
 It is the sweetest of all sugars
 Galactose- is produced from lactose and is converted to glucose
in order to be absorbed by the body.
Disaccharide
 These are made up of 2 monosaccharides for example;
 Sucrose= fructose + glucose
 Lactose= galactose + glucose
 Maltose= glucose + glucose
 Sources
 Sucrose (table sugar) found in sugar cane, sorghum cane, brown
sugar, pineapple
 Lactose found in milk , it is formed in the body from
 Maltose is found in malt products and germinated cereals

10. Polysaccharides
 These are complex carbohydrates made up of many units of
monosaccharide such as starches, glycogen, cellulose.
 Starches and glycogen are the only polysaccharides of
nutritional importance because they can be ingested in the
human gut.
 Starches
 These consists of two polysaccharides namely amylose and
amylopectin. Starch is the carbohydrate found in plants.
 Amylose
 The amylose molecule consists of glucose units between 70-
350 joined in a straight chain.About 20% of starches is amylose
 Amylopectin
 This molecule consists of up to 100,000 units of glucose joined
in a branched chain. It consists of 80% of starches.
 Glycogen
 This is a carbohydrate found only in animals. It can be thought
of as a reserve in animals, just like starch is the reserve for
carbohydrates in plants.

11. Glycogen
 Glycogen is composed glucose units with branched
chains.
 It is soluble in water.
 Animals are capable of storing glycogen in muscles and
the liver.
 When required the glycogen is converted into glucose
and used by the body to provide energy.
 The enzyme which converts glycogen to glucose is called
glucagon.
 Glucose can be formed from proteins and fats by
gluconeogenesis which occurs in the liver and kidneys.
 Excess carbohydrates
 Excess intake of carbohydrates may lead to obesity.
 Low carbohydrates
 If carbohydrates are not enough or absent, fats and
protein are used to provide energy needed by the body.

12. Functions of carbohydrates
 They provide energy
 The carbohydrate dextran is a
polysaccharide used in medicine as a
blood-plasma-volume expander to
counteract acute shock;
 another carbohydrate, heparin sulfate, is
a blood anticoagulant.
 Also used in the production of adhesive
materials, sizing materials, and emulsions

13. Digestion of carbohydrates
 Digestion: This is a chemical break down of
different complex compound present in the
food particles which have been physically cut
by the action of teeth and jaws.
 It is brought about by the means of
chemical compound called enzymes
 Amylase, found in saliva and in the
intestine, breaks starch, dextrin, and
glycogen into maltose.
 Maltase breaks maltose into glucose, it
breaks cane sugar into glucose and fructose;
lactase breaks milk sugar into glucose and
galactose.

14. Digestion in the mouth
 In the mouth, food is chewed and mixed
with saliva.
 Saliva is composed of water, mucin
(lubricates food) and amylase.
 chewing reduces the food to be suitable for
swallowing and increased the available
Digestion in the stomach
 From mouth the food passes through the
oesophagus into stomach which acts like a
reservoir because food needs to be
consumed at intervals.
 No digestion of CHOs takes place in
the stomach.

15. Digestion in the intestines
 The small intestines are composed of 3 parts;
these are duodenum, jejunum and ileum.
 Of the 3 pancreatic enzymes, amylase is the one
which act on starch and change it into maltose.
 This means that the starch which was not digested
in the mouth can now be acted upon in the small
intestines.
 From the duodenum, the food enters in
ileum.
 In here it meets the intestinal juice which contains
the following enzymes; enterokinase, peptidase,
maltase and sucrase.

16.  Among these enzymes, maltase and sucrase are the ones
which act on CHOs:
 maltase, acts on maltose and changes into 2 glucose
molecules,
 sucrase acts on sucrose as a result which yields fructose and
glucose.
Absorption
 Nearly all the digested food is absorbed in the ileum
 Properties of the ileum that are important to its function of
absorption :
 It provides large surface area. Its internal surface is increased
by finger like projection called villi.
 The lining epithelium is thin and fluids can pass fairly rapidly
through it.
 There is a dense network of blood capillary in each villi.

17. Absorption of carbohydrates
conti….
 Glucose is absorbed into the bloodstream through
the intestinal wall.
 Some of this glucose goes straight to work in our
brain cells and red blood cells, while the rest
makes its way to the liver and muscles, where it
is stored as glycogen (animal starch), and to fat
cells, where it is stored as fat.

18. Daily requirements of
carbohydrates
 The body needs about 45 to 65 percent of your
total daily calories.
Effects of carbohydrates deficiency and
excess
Effects of carbohydrates deficiency causes marasmus
while excess causes obesity, Non-insulin dependent
diabetes mellitus, dental carries.

19. PROTEINS
 Proteins are made of smaller units called amino
acids.
 Dietary proteins are powerful compounds that build
and repair body tissues, from hair and fingernails to
muscles.
 In addition to maintaining the body’s structure,
proteins speed up chemical reactions (enzymes) in
the body
 They serve as chemical messengers, fight infection
(immunoglobulins)
 Transport oxygen from the lungs to the body’s tissues
(haemoglobin).

20. Cont…..
 protein provides 4 calories of energy per
gram
 The body uses protein for energy only if
carbohydrate and fat intake is insufficient.
 When tapped as an energy source, protein is
diverted from the many critical functions it
performs for our bodies.

21. Classification of
AMINO ACIDS

22. Based on nutritional requirements:
Essential amino acids:
• These cannot be made by the body.
• As a result, they must come from food.
• Examples: Arginine, histidine, isoleucine,
leucine, lysine, methionine, phenylalanine,
threonine, tryptophan, and valine.
Non essential amino acids:
• These can be synthesized/made by the body.
• Examples: Alanine, asparagine, aspartic acid,
cysteine, glutamic acid, glutamine, glycine,
proline, serine, and tyrosine.

24. Classification
PROTEINS

25. Classification based on composition
 Proteins are classified into simple, compound and
derived
Simple proteins
 These are made up of only amino acids. Examples
albumin found in egg, serum in blood. Globulin found
in blood.
Conjugated/Compound proteins
 These are compounds of single and other none
protein groups
 Examples; Glycoprotein, Mucoprotein,
Phosphoprotein, Lipoprotein, Chromo-protein

26. CLASSIFICATION BASED
ON QUALITY
 Complete Proteins
 These are amino acid which contain all
the amino acids in sufficient manner e.g.
animal foods
 Incomplete Proteins
 These are proteins in which one or more
of the essential amino acids are not
present e.g. beans, maize, groundnuts

27. CLASSIFICATION BASED ON
FUNCTION
 Structural proteins- connective tissue
 Contractile- muscle
 Antibodies- gamma globulin which destroys
bacteria
 Blood proteins- albumin, fibrinogen for clotting
of blood
 Hormones – facilitation of body metabolic
activities
 Enzymes- for digestion of food
 Transport protein- phosphoprotein, ferritin it
helps in the transportation

28. Sources of Proteins
 Animal proteins, found in such food as eggs,
milk, meat, fish, and poultry, are considered
complete proteins because they contain all of
the essential amino acids our bodies need.
 Plant proteins, found in vegetables, grains, and
beans, lack one or more of the essential amino
acids and make up incomplete proteins.
 However, plant proteins can be combined in the
diet to provide all of the essential amino acids.A
good example is rice and beans.

29. Making incomplete proteins complete
 Plant proteins can be combined in the diet to
provide all of the essential amino acids.
 A good example is rice and beans.
 Each of these foods lacks one or more essential
amino acids, but the amino acids missing in rice
are found in the beans, and vice versa.
 So when eaten together, these foods provide a
complete source of protein

30.  people who do not eat animal products can meet
their protein needs with diets rich in grains, dried
peas and beans, rice, nuts, and tofu, a soybean
product.
 Some health conditions, such as illness, stress, and
pregnancy and breast-feeding in women, place an
enormous demand on the body as it builds tissue
or fights infection, and these conditions require an
increase in protein consumption
 For example, a healthy woman normally needs 45
grams of protein each day. Experts recommend that
a pregnant woman consume 55 grams of protein
per day, and that a breast-feeding mother consume
65 grams to maintain health.

31. DIGESTION OF PROTEIN
Mouth
 No digestion of proteins in the mouth
Stomach
 The gastric juice is produced by the lining cells of the
gastric mucosa.This juice contain inactive enzyme
called pepsinogen.
 This enzyme is activated into pepsin by hydrochloric
acid and break down protein into polypeptides.
 HCL acid also creates a conducive acidic environment
for the digestion of protein.
 gastric mucus has the alkaline properties to protect
the mucosa lining from corrosive acids.
 The food descends into small intestine

32. Digestion in the s.intestines
 The chyme in the s. intestine is exposed to the
two digestive juices namely pancreatic juices
and intestinal juice
 Pancreatic Juices- contain trypsin which acts
on undigested protein from the stomach into
polypeptides and further to dipeptides
 Intestinal juice- is produced by the glands on the
walls of the duodenum and ileum; contain the
enzymes like peptidases which finally converts the
remaining polypeptides and dipeptides into amino
acids

33. ABSORPTION
 All the digested amino acid passes through
the epithelium and capillary walls of the
intestine and enters the blood plasma.
 They are then carried away in the capillaries
which join to form a large vein called hepatic
portal vein.
 Once the amino acid reaches the general
circulation they are taken to the parts of the
body where they are needed/ used or
stored.

34. FUNCTIONS of PROTEINS
 To replace worn out tissues in the body
 To provide raw materials for growth
 Provides ingredients in the formation of
important body compounds e.g.
haemoglobin, antibodies, enzymes
 Proteins regulate body fluids. In
kwashiorkor patients reduced protein
supply lead to fluid imbalance eg oedema
 In starvation conditions proteins provide
energy which is needed.

35. Effects of proteins in excess
Obesity
Overweight
Deficiency
Kwashiorkor
Underweight
marasmus

36. FATS/LIPIDS
Fats
 Fats are substances composed of lipids
or fatty acids and occurring in various
forms or consistencies e.g. oil.
Chemical composition of fats
 Fats consist of carbon, hydrogen and oxygen,
but they differ from carbohydrates in that the
hydrogen and oxygen are not in the same
proportions as in water.

37. Classification of fats
 Saturated or animal fat, contain mainly
saturated fatty acids and glycerol, are
found in milk, cheese, butter ,eggs, meat.
 These contribute to a lot of cancers and
heart diseases.
 Unsaturated or vegetable fat, contain
mainly unsaturated fatty acids and
glycerol, are found in some margarine and
in most vegetable oil.

38. Classification of fats cont..
Depending on the dietary requirements
fats are of two kinds - essential and non-essential.
 Essential fats are those that are not synthesized
by the body and have to be included in the diet e.g
linoleic acid (Omega-3 fatty acid), linolenic acid
(omega-6 fatty acid), arachidonic acid are
polyunsaturated fatty acids.
 Non-essential fats are those that are synthesized
by the body and are not necessary in the diet,
example glycine.

39. Dietary sources of fats
 The dietary sources of fats include: milk, cheese, butter,
eggs, meat, oily fish, margarine, and vegetable oils.
FUNCTIONS OF FATS
 Fats provide energy- fats are the most efficient
source of food energy because they provide a reservoir
of energy for long term storage, which can be used if
energy intake is restricted.
 Each gram of fat provides 9 calories of energy for the
body compared to 4 calories per gram of carbohydrates
and proteins.
 Fats build health cells- fats are a vital part of the
membrane that surrounds each cell of the body.
 Without a healthy cell membrane, the rest of the cell
cannot function properly.

40. Functions of fats cont..
 Fats build brains- fats provide structural
components not only of the cell membrane in the
brain but also of the myelin.The fatty insulating
sheath that surrounds each nerve fibre enables it to
carry messages faster.
 Fats help the body use vitamins- vitamins A, D, E
and K are fat soluble vitamins, meaning the fats in
food help the intestines absorb these vitamins into
the body.

41. Functions of fats cont..
 Fats make hormones- Fats regulate the
production of sex hormones, which explains why
some teenage girls who are too thin experience
delayed pubertal development and amenorrhoea.
 Fats provide healthier skin- one of the most
obvious signs of fatty acid deficiency is a dry flaky
skin.
 Fat acts as the body’s own insulation to help
regulate body temperature (subcutaneous tissue).
Thin people tend to be most sensitive to cold and
obese people tend to be sensitive to warm weather.

42. Functions of fats cont..
 Fats form of protective cushion for body
organs- e.g kidneys, heart and intestines are
cushioned by fats that helps and protect them from
injury and hold them in place.
 These protective fats are the last to be used up when
the body’s energy reserves have been depleted.
 Fats are pleasurable- besides being a nutritious
energy source, fats add to the appealing taste, texture,
appearance of the food and carry flavor.The foods
containing fats provide a feeling of fullness after a
meal as fat digestion is slow.

43. Digestion, absorption and
metabolism of fats
 Digestion of fats begins in the duodenum and
ends in the duodenum; the presence of fat in the
small intestines stimulates the secretion of
hormones cholecystokinin (CCK) and secretin
from the duodenal cells.
 CCK signals the gallbladder to contract sending
bile down the bile duct and into the duodenum
were fat is emulsified by bile from the gallbladder.
 Secretin signals the pancreas to release pancreatic
juice rich in pancreatic lipase.
 The pancreatic lipase converts the emulsified fats
into fatty acids and glyceral.

46. Digestion, absorption and
metabolism of fats cont..
 Fatty acids and glycerol are then absorbed
into lacteals of the intestinal villi and
carried to the blood stream.
 It is then transported to the liver, fatty
acids and glycerol circulating in the blood
are used by the cells of organs and glands
to provide energy and some are re-
combined forming triglycerides

47. Daily requirement of fat
 The daily requirements of fat intake should
be equal to 30% of your total day’s calories
Effects of deficiency and excess of fat
Fat deficiency has been linked with
 Atherosclerosis (hardening of the arteries),
increased triglyceride levels and reduced
high density lipoprotein (HDL) cholesterol
levels restricting blood flow to the heart.
 Scaly skin rash and dermatitis.

48. Effects of deficiency and excess of
fat cont..
 Poor growth in children.
 Lower immune response.
 Neuropathy
 Visual disturbance.
Excess fats in the body causes
 Obesity-is highly associated with the risk
of type II diabetes, and gall bladder
disease.

49. Conti….
 Cardiovascular diseases such as
hypertension, atherosclerosis etc.

50. Next Lecture
UNIT TWO
APPLIED NUTRITION
ASSESSMENT METHODS

51. Assignment 1:ALL
 Nutrients are substances that are found in
food which are meant to nourish the
body. Nutrients include vitamins and
minerals among others.
QUESTION ONE: in a table form, discuss
the different types of vitamins under the
following headings:
Vitamin
Common
Name
Chemical
name
Daily
requirement
s
Functions Effect of
excess
Effect of
deficiency

52. Assignment:ALL
 QUESTIONTWO: in a table form, discuss
the different types of minerals under the
following headings:
Minerals Name Daily
requirements
Functions Effect of excess Effect of
deficiency

53. Assignment Two:ALL
 Discuss the different methods of food
processing, stating the advantages and
disadvantages with reference to the
following headings:
 Preservation
 Cooking
 Storage

54. Reading assignment
 Anaemia is a condition in which there is
lack enough healthy red blood cells to carry
adequate oxygen to the body's tissues.
Several causes have been identified that
include, haemorrhage, osteoblastic disorders
and nutrient deficiency.
 QUESTION: Discuss nutrient deficiency
anaemia focussing on the causes,
presentation (signs and symptoms),
management and prevention.