2. LEARNING OBJECTIVES
By the end of this lecture the reader should
be able to:
To know the concept of nutrition and classifications of food
To understand diet planning and dietary guidelines
To understand therapeutic nutrition
To know the different methods for assessing the nutritional
To understand the basic anthropometric techniques,
applications, & reference standards
To know hazards of obesity
Nutrition is the most important health promoting
Good nutrition is an essential requirement for good
Adequate nutrition is the necessary first step for the
improvement of the quality of life.
Science of Nutrition
The study of food and the substances they contain
The study of nutrients - their action, interaction and
balance – in relation to health and disease
Nutrition means dynamic process in which food taken is
utilized (the process of providing the individual with
Food: derived from plant or animal sources
Diet: the foods one consumes
Nutrients: substances used by the body to supply energy,
promote growth and repair of body tissues and regulate body processes
8. Classification of foods
3. Classified by the amount required for the body:
Macronutrients: these are proteins, fats and
carbohydrates. They form the main bulk of food. They are
required by the body in relatively large amounts (measured in
Micronutrients: these are vitamins and mineral. They are
called micronutrients because they are required in small
amounts (measured in milligrams or micrograms).
10. Dietary fibres
Are exclusively found in plant food, which the body cannot digest or
absorb into the blood stream, therefore cannot be properly
considered a nutrient.
Basically, fiber is ingested into the body and expelled virtually intact
Fibers is found in two forms;
1. Soluble fibers: dissolve in water
Sources : peas, and some fruits such as apple and orange, and several
vegetables including carrots, and cauliflower.
Functions : binds to fatty substances and promotes their excretion, which
helps lower blood cholesterol levels.
11. Dietary fibres
2. Insoluble fiber is known as “ roughage “: do not dissolve in water
Valuable of roughage :
•It is needed to form the bulk of the intestinal contents.
•It helps the intestine to perform its normal movements.
•It prevents constipation and cancer of the colon.
•It may also help reduce the risk of digestive problems, heart diseases,
diabetes, and promote weight loss.
Sources: whole wheat products, wheat bran, corn bran, and many vegetables
including cauliflower, and green beans).
Total recommended daily amount of dietary fiber:
Between 25 to 35 grams from natural source foods.
However, consuming excess amounts of fiber (more than 50 to 60 grams per
day) may cause a decrease in the amount of vitamins and minerals that body
absorbs, and can also cause flatulence, diarrhea.
It should also be noted that the older we are, the more daily fiber required in
12. Characteristics of good food
Adequate quantity and quality that satisfy
Safe, free of infection, toxicity and
13. How much do we need?
Dietary Reference Intakes: a set of nutrient
intake values used for planning and assessing
1. Estimated Average Requirements
2. Recommended Dietary Allowances
3. Adequate Intakes
4. Tolerable Upper Limits
14. How much do we need?
1. Estimated Average Requirement:
The average daily amount of a nutrient needed in the
diet that will maintain physiological activities and reduce
Different criterion for each nutrient and each gender and
age group of people
2. Recommended Dietary Allowances (RDA):
Estimates for average daily nutrient intakes which are
believed adequate to prevent deficiency
15. How much do we need?
3. Adequate Intakes:
A value used as a guide for sufficient nutrient intake
when there is insufficient scientific evidence to
establish a RDA
4. Tolerable Upper Intake Levels:
The maximum daily amount of a nutrient that appears
safe for most healthy people
16. Estimated energy requirement
The average dietary energy intake that maintains
energy balance in a healthy person of a given
age, gender, weight, height, and activity level
Acceptable Macronutrient Distribution Ranges:
Carbohydrate: 45% - 65%
Fat: 20% - 35%
Protein: 10% - 35%
17. Diet Planning Principles
1. Adequacy: providing sufficient energy and essential nutrients for
2. Balance: consuming the right proportion of foods
3. Energy control: balancing the amount of foods and energy to sustain
physical activities and metabolic needs
4. Nutrient density: measuring the nutrient content of a food relative to
its energy content
5. Moderation: providing enough but not too much of a food or nutrient
6. Variety: eating a wide selection of foods within and among the major
18. Estimation of caloric needs
There are several different formulas for determining
estimated caloric needs. All are based on the principles of
energy balance: Energy being used up or expended
throughout the day should be equally consumed for weight
Weight loss occurs when energy intake is lower than
estimated energy output, and weight gain occurs when
energy intake is greater than estimated energy output.
Many different factors effect someone's energy output, such
as age, sex, height, weight and energy level. It is important
to determine daily caloric intake, to achieve the right energy
input balance to suit your lifestyle.
19. Estimation of caloric needs
Caloric intake equations are based on determining a person's resting
This is the energy necessary to sustain life and to keep the heart,
lungs, brain, liver and kidneys functioning properly.
Resting energy expenditure accounts for about 60 to 75 percent of
total daily energy expenditure.
The remaining energy expenditure is through physical activity,
about 25 percent, and through the metabolic process of digesting
food, about 10 percent
20. Estimation of caloric needs
Mifflin-St. Jeor equation (modified Harris-Benedict
Resting Metabolic Rate(RMR)=
for females= 10 x (Weight in kg) + 6.25 x (Height in cm) - 5 x (age in
years) – 161
for males= 10 x (Weight in kg) + 6.25 x (Height in cm) - 5 x (age in
years) + 5.
These equations are also multiplied by the same physical activity factors
to estimate daily kilocalories needed.
Little to no exercise: RMR x 1.2
Light exercise (1–3 days per week): RMR x 1.375
Moderate exercise (3–5 days per week): RMR x 1.55
Heavy exercise (6–7 days per week): RMR x 1.725
Very heavy exercise (twice per day, extra heavy workouts): RMR x 1.9
21. The food pyramid
Definition: The food Pyramid Guide was designed to
establish recommended Dietary Guidelines, and contains
the building blocks essential to a healthy diet.
It has the guidance required to recognize what and how
much to eat of the five major food groups.
23. The food pyramid
Keep our fat intake and total cholesterol at
recommended levels, and identify the essential
nutrients that make up a healthy diet for
maintaining our fitness.
Balance the food groups in our diet.
Supply a nutrition equilibrium by keeping total
calorie count in line with weight loss and weight
24. Food Exchange system list
It provide a framework to group foods with similar carbohydrate,
protein, fat, and calorie contents
Each list is a group of measured or weighed foods of approximately
the same nutritional value .
The word exchange refers to the food items on each list which may be
substituted with any other food item on the same list.
One exchange is approximately equal to another in carbohydrate,
calories, protein and fat within each food list.
The exchange lists are used for weight management as well for
25. Therapeutic nutrition
Therapeutic nutrition refers to the use of diet as a therapeutic tool in the
management of patients.
The major effort of all therapeutic nutritional program is to insure total adequacy of
good nutrition, prevent deficiencies and correct abnormal nutritional states.
In constructing a diet for a patient, it is necessary to take into account the following
the normal daily needs of the patient.
Previous nutritional depletion.
Increased requirements resulting from current losses as by vomiting and
The composition of a patient’s diet should not be based upon the recommended
daily dietary allowances for healthy people because this does not take into account
the additional demands for specific nutrients.
26. Therapeutic nutrition
The caloric content of a diet, is determined by calculating:
the total number of calories normally required by the patient.
The amount of calories lost from the system by vomiting and diarrhea or form
the skin in burns.
Extra needs produced by fever and other metabolic causes.
The amount needed to compensate for previous weight loss.
The patient’s caloric status as determined by height and weight.
The presence of edema should be taken into account when evaluating weight
to height status.
27. Therapeutic nutrition
Modifications in conscistency and Texture of foods:
1. Clear liquid diet:
The diet is highly restrictive and is of little nutritive value; it provide some electrolyte,
mainly sodium, chloride, and potassium.
Indications for use: as a progression between IV feeding and a full liquid or solid diet
following certain types of surgery
e.g. coffee, tea, fruit juices, carbonated beverages.
2. Full liquid diet:
It provide an oral, nourishment that is well tolerated by patients who are actually ill or
who are unable to swallow.
Indications for use: following oral surgery or plastic surgery of the face and neck. In
patients with esophageal strictures, and following mandibular fractures.
E.g.: milk, eggs, vegetable’s juices.
28. Therapeutic nutrition
Modified fiber diet: which is classified
1. Fiber restricted diet:
A diet that contains a minimum of fiber and connective tissue.
Indications: During acute phase of diverticulosis, ulcerative colitis or
infectious enterocolitis when the bowel is inflamed.
2. High fiber diet:
A diet that contains increased amounts of cellulose, semicellulose and
Indications: in constipation, uncomplicated diverticulosis and the irritable
29. Therapeutic nutrition
Modification in protein contents:
1. High protein, high kilocalories diet:
Provides a level of total kilocalories and protein substantially above that which is normally
Indications: Protein kilocalorie reduction, catabolic state, anorexia nervosa.
2. Controlled protein, potassium, sodium diet:
The dietary intake of Na. K and protein are carefully regulated from day to day.
Indications: When the glomerular filtration rate below 20-30 ml/minute. For the patients
not receiving dialysis severe restrictions are necessary.
Modification in carbohydrate contents:
Carbohydrate restricted diet for the management of the dumping syndrome.
Galactose free diet.
Lactose free diet.
Sucrose restricted diet.
Modifications in fat contents:
Fat restricted diet.
30. Diagnostic category Diet Order Comment
Peptic ulcer Diet individualized for patient
tolerance with small frequent feedings
Consult dietitian to obtain patient
tolerance; restriction of caffeine, black
pepper and alcohol.
High fiber diet Includes whole grain bread and cereals,
fresh and dried fruits, raw vegetables.
Hepatitis Regular diet High calories, high protein diet
Acute liver failure Trace protein, fat free diet Specify grams protein and fat; initially
8-10 gm protein and approximately
2gm fat suggested consists mainly of
fruits and fruit’s juices.
Renal disorder, renal insufficiency Protein, sodium, potassium, fluid
Post-transplant (kidney) High protein, low sodium, low sugar
diet, low calories to prevent weight
1-2 gm sodium and 120-150 gm protein
31. Diagnostic category Diet Order Comment
Congestive heart failure Sodium restricted diet 0.5-1 gm sodium
Hypertension Sodium restricted diet 2-3 gm sodium
Myocardial infarction Progress from clear liquid to a low fat,
soft-sodium restricted diet with small
frequent feedings as tolerated; initially
no hot or cold foods or caffeine.
40 gm fat
Hypercholestrerolaemia Low cholesterol, low fat diet Less than 300 mg cholesterole, 25-
30% calories as fat.
Hypertriglyceridaemia Moderate restriction in total fat;
sucrose and alcohol restricted, calories
for ideal body weight
30-35% calories as fat with complex
carbohydrate such as fresh fruits,
Diabetes mellitus (non insulin
Sucrose and saturated fat restricted
diet. Calories for ideal body weight
Specific calories. % of protein,
carbohydrate and fat; 50%
carbohydrate, 30% fat and 20%
As above + daily distribution of
As above + specify type and timing of
insulin; complex carbohydrate such as
vegetables, fresh fruits.
32. Lecture Two
The nutritional status of an individual
is often the result of many inter-
It is influenced by food intake,
quantity & quality, & physical health.
The spectrum of nutritional status
spread from obesity to severe
33. Nutritional Assessment Why?
The purpose of nutritional assessment is
Identify individuals or population groups
at risk of becoming malnourished
Identify individuals or population groups
who are malnourished
To develop health care programs that meet the
community needs which are defined by the
To measure the effectiveness of the nutritional
programs & intervention once initiated
34. Methods of Nutritional Assessment
Nutrition is assessed by two types of
methods; direct and indirect.
The direct methods deal with the
individual and measure objective
criteria, while indirect methods use
community health indices that
reflects nutritional influences.
35. Direct Methods of Nutritional
These are summarized as ABCD
Biochemical, laboratory methods
Dietary evaluation methods
36. Indirect Methods of Nutritional
These include three categories:
Ecological variables including crop
Economic factors e.g. per capita
income, population density & social
Vital health statistics particularly
infant & under 5 mortality & fertility
37. Anthropometric Methods
Anthropometry is the measurement of
body height, weight & proportions.
It is an essential component of clinical
examination of infants, children &
It is used to evaluate both under & over
The measured values reflects the
current nutritional status & don’t
differentiate between acute & chronic
38. Anthropometric Measurements
< 24 months
% Usual body
% Ideal body weight
Skin fold thickness
< 3 years of age
39. Anthropometry for children
Accurate measurement of height and
weight is essential. The results can
then be used to evaluate the physical
growth of the child.
For growth monitoring the data are
plotted on growth charts over a period
of time that is enough to calculate
growth velocity, which can then be
compared to international standards
43. Measurements for adults
The subject stands erect & bare
footed on a stadiometer with a
movable head piece. The head
piece is leveled with skull vault
& height is recorded to the
nearest 0.5 cm.
47. Nutritional Indices in Adults
The international standard for assessing
body size in adults is the body mass index
BMI is computed using the following
formula: BMI = Weight (kg)/ Height (m²)
Evidence shows that high BMI (obesity level)
is associated with type 2 diabetes & high risk
of cardiovascular morbidity & mortality
49. Waist/Hip Ratio
Waist circumference is measured
at the level of the umbilicus to
the nearest 0.5 cm.
The subject stands erect with
relaxed abdominal muscles, arms
at the side, and feet together.
The measurement should be
taken at the end of a normal
50. Waist circumference
Waist circumference predicts mortality better
than any other anthropometric
It has been proposed that waist
measurement alone can be used to assess
obesity, and two levels of risk have been
LEVEL 1 (accepted) > 94cm > 80cm
LEVEL2 (obesity) > 102cm > 88cm
51. Hip Circumference
Is measured at the point of greatest
circumference around hips & buttocks to
the nearest 0.5 cm.
The subject should be standing and the
measurer should squat beside him.
Both measurement should taken with a
flexible, non-stretchable tape in close
contact with the skin, but without
indenting the soft tissue.
52. Interpretation of WHR
High risk WHR= >0.80 for females &
>0.95 for males i.e. waist
measurement >80% of hip
measurement for women and >95%
for men indicates central (upper
body) obesity and is considered high
risk for diabetes & CVS disorders.
A WHR below these cut-off levels is
considered low risk.
53. ADVANTAGES OF ANTHROPOMETRY
Objective with high specificity &
Measures many variables of nutritional
significance (Ht, Wt, MAC, HC, skin fold
thickness, waist & hip ratio & BMI).
Readings are numerical & gradable on
standard growth charts
Readings are reproducible.
Non-expensive & need minimal training
54. Limitations of Anthropometry
Inter-observers errors in
Limited nutritional diagnosis
Problems with reference standards,
i.e. local versus international
Arbitrary statistical cut-off levels for
what considered as abnormal values.
56. Biochemical (laboratory)
Hemoglobin estimation is the most
important test, & useful index of the
overall state of nutrition. Beside
anemia it also tells about protein &
trace element nutrition.
Stool examination for the presence of
ova and/or intestinal parasites
Urine dipstick & microscopy for
albumin, sugar and blood
57. Specific Lab Tests
Measurement of individual nutrient
in body fluids (e.g. serum retinol,
serum iron, urinary iodine, vitamin
Detection of abnormal amount of
metabolites in the urine (e.g. urinary
Analysis of hair, nails & skin for
58. Advantages of Biochemical Method
It is useful in detecting early changes
in body metabolism & nutrition before
the appearance of overt clinical signs.
It is precise, accurate and
Useful to validate data obtained from
dietary methods e.g. comparing salt
intake with 24-hour urinary excretion.
59. Limitations of Biochemical Method
They cannot be applied on large scale
Needs trained personnel & facilities
60. CLINICAL ASSESSMENT
It is an essential features of all
It is the simplest & most practical
method of ascertaining the nutritional
status of a group of individuals
It utilizes a number of physical signs,
(specific & non specific), that are
known to be associated with
malnutrition and deficiency of vitamins
61. CLINICAL ASSESSMENT/2
Good nutritional history should be
General clinical examination, with
special attention to organs like hair,
angles of the mouth, gums, nails,
skin, eyes, tongue, muscles, bones,
& thyroid gland.
Detection of relevant signs helps in
establishing the nutritional diagnosis
65. Clinical signs of nutritional deficiency
Vitamin A deficiencyNight blindness,
Vit B2 & vit A
66. Clinical signs of nutritional deficiency
Protein deficiencyTransverse lines
67. Clinical signs of nutritional deficiency
Folic acid, iron, B12Pallor
Vitamin B & Vitamin CFollicular
PEM, Vit B2, Vitamin A,
Zinc & Niacin
Niacin & PEMPigmentation,
Vit K ,Vit C & folic acidBruising, purpura
68. Clinical signs of nutritional deficiency
areas and far from
sea places Goiter is
a reliable sign of
69. Clinical signs of nutritional deficiency
Joins & bones
Help detect signs of
& vitamin C
70. DIETARY ASSESSMENT
Nutritional intake of humans is
assessed by five different methods.
24 hours dietary recall
Food frequency questionnaire
Dietary history since early life
Food dairy technique
Observed food consumption
71. 24 Hours Dietary Recall
A trained interviewer asks the
subject to recall all food & drink
taken in the previous 24 hours.
It is quick, easy, & depends on short-
term memory, but may not be truly
representative of the person’s usual
72. Food Frequency Questionnaire
In this method the subject is given a
list of around 100 food items to
indicate his or her intake (frequency &
quantity) per day, per week & per
inexpensive, more representative &
easy to use.
75. DIETARY HISTORY
It is an accurate method for
assessing the nutritional status.
The information should be collected
by a trained interviewer.
Details about usual intake, types,
amount, frequency & timing needs
to be obtained.
Cross-checking to verify data is
76. FOOD DAIRY
Food intake (types & amounts)
should be recorded by the subject at
the time of consumption.
The length of the collection period
range between 1-7 days.
Reliable but difficult to maintain.
77. Observed Food Consumption
The most unused method in clinical practice,
but it is recommended for research purposes.
The meal eaten by the individual is weighed
and contents are exactly calculated.
The method is characterized by having a high
degree of accuracy but expensive & needs time
78. Interpretation of Dietary Data
1. Qualitative Method
using the food pyramid & the basic
food groups method.
Different nutrients are classified
into 5 groups (fat & oils, bread &
cereals, milk products, meat-fish-
poultry, vegetables & fruits)
determine the number of serving
from each group & compare it with
79. Interpretation of Dietary Data/2
2. Quantitative Method
The amount of energy & specific nutrients
in each food consumed can be calculated
using food composition tables & then
compare it with the recommended daily
Evaluation by this method is expensive &
time consuming, unless computing facilities
80. Food balance sheet
Definition: It determines the individual
share from different foods assuming that
the available food is distributed equally
Or the food balance sheet determines the
food consumption level per head per day
assuming adequate distribution.
81. Food balance sheet
The food balance sheet is a method for:
Assessment of National food consumption.
Determining the individual share of food
consumption per day, assuming adequate
distribution for the available food.
The first food balance sheet in Egypt was
conducted in 1947-1948.
82. Food balance sheet
It shows quantities and types of food available for
It can serve as an index for obvious deficit. Hence we can
develop and build the agriculture policy to meet the
nutritional requirement of the population.
It can show to what extent the country dependent on others.
It can be used to a certain extent for comparing the food
consumption level in different countries.
When these data tabulated together along number of years,
it shows the pattern of diet and change in it.
83. Food balance sheet
Basic feature (or pattern) of Egyptian
Energy is more than average.
Cereals (especially bread) form a good bulk of
diet and supply the greater part of energy,
protein, iron and vit. B.
Animal food content is low.
Protein intake is largely from plant sources.
Iron intake is in excess, but largely from plant
origin with lower absorbability.