UNIT 3
Specific Objectives:
At the end of this unit, students will be able to:
1) Know the importance of dividing nutrition into
groups.
2) Identify the nutritional alternatives.
3) Identify the factors affecting choosing nutrition.
4) Discuss the nutritional needs of adult, children,
pregnant, lactating mothers and the old age.
•
Basic Nutritional Groups
Importance of dividing nutrition into groups
We have to take into our consideration the following:
1. Consider the age, sex, weight, developmental stage, the health status and
the type of work of the individual or the group is engaged in.
2. Every day should be considered as one unit.
3. The diet plan should be adequate, in other word it should :
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–
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Supply all energy requirements, protein, minerals, vitamins and water.
Adequate according to the needs of the individual.
Digestible.
Free from infection and poisonous chemicals.
In planning diets whether through the
quantitative or qualitative method we
must consider:
1.Needs for growth and development.
2.Needs for type of work and mode of life.
3.Needs during infection.
4.Inter relationship of nutrients.
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• (A)Needs for growth and development:
The nutritional needs for young healthy
children are great as would be expected from
the rapid rate of growth, in particular, the
requirements for protein calories and iron are
much greater proportionally in young children
than adults, so a 70kg man needs about 70mg
of protein daily in comparison a child of 12kg
needs about 25gm of protein daily.
.
(B) Needs according to the type of work and
mode of life:
Workers engaged in sedentary works require different diets
than those, who are involved in heavy activities;
The later need diets rich in calories and thiamin; workers
working in a hot environments which will involve much
sweating, water and salt intake should be stressed. Since salt
absorption is improved if glucose is present, workers should
take some carbohydrate as well as salt and water.
For these purpose 0.2% salt solution can be drunk or used with
sweetened lemonades.
(C)Needs during infection:
In malnourished children, infection occurs easier, last a longer
time and have much mortality rates.
On the other hand, infections play an important role in the
initiation of malnutrition: many infections are characterized
by poor appetite, vomiting and diarrhea. During infection
there is a need for more calories.
In fact, the basal energy requirements increases by 13% for
every degree centigrade rise in temperature above normal; it
has been known that in almost all febrile infections there is an
increase in the excretion of nitrogen in urine, nitrogen loss
may begin during the prodromal stage before the appearance
of fever and clinical symptoms and may continue long after
the fever subside.
(D)Inter relationship of nutrients:
The body needs for different nutrients are related to
one another, e.g. the requirements for the vitamin
thiamin increases in the intake of carbohydrate.
I - The quantitative method of diet planning:
1. Determine first the daily caloric requirement.
Basal metabolism.
This the metabolism of the body when it is in the state
of rest 4 hours after the food intake; it is constant per
square meter/hour. It can also be assessed using the
weight of the individual. It is one caloric/kg body
weight/hour.
There are various factors that can affect the basal
metabolism:
These includes sex, weight, height, skin area, age as
well as pathological conditions as thyrotoxicosis and
febrile condition.
Total metabolism:
Equal to basal metabolism activities carried out by the individual.
Example:
Type of activity
- rest in bed.
- limited activities.
- light activities
- moderate activities
- heavy activities
% increases in the
metabolism
10%
30%
50%
75%
100%
(2) Calculate the amount of protein needed by the
subject, and then find out the calories given by these
proteins;
if for example a person takes one gm of protein/kg of
his body weight and he has a weight of 65kg, then he
will need 65gm of proteins then will yield 65
multiplying by 4 = 260 calories (where 1 gm of
protein gives 4 calories).
3)All the recommended allowances of minerals
and vitamins should be
supplied and part of the protein should come from
animal kingdom.
•
II- The qualitative method:
A)Group 1:
Body building foods: meat, fish, eggs,
milk and cheese. These groups provide
protein, niacin, thiamin, riboflavin and iron.
B) Group II:
The bone building foods: milk and cheese, also
cod liver oil; these groups provides calcium.
They also supply high biological protein and
riboflavin: these group of foods is needed
highly for growing children and pregnant and
lactating women.
(C) Group III:
The vitality foods: Fruits and vegetables,
provides vitamins especially C and A and
mineral especially iron.
(D) Group IV:
Energy giving foods: Fats as butter, cream,
oils. Cereals as bread, macaroni, rice and
cakes, jams, and honey. These groups provides
mainly energy workers involved in heavy
activities and athletes require more of the
energy group.
Children Nutrition:
A) Bite size pieces of food which can be easily
picked up with finger or spoon by the
young child be provided.
1-Such foods as raw carrots should be avoided
until they can be chewed well and
there is no danger of aspiration.
2-Food should be saved in small portions so as
not to overwhelm the child.
B) During the second year of life, growth rate to
decelerates, calorie requirements drop, and
children demonstrate marked disinterest in food,
children should not be forced to eat: if they
refuse, the food be removed without comment,
and offered again at the next meal.
C) A child should be encourages to food himself as
soon as he is ready to manipulate a cup and
spoon.
D) It is helpful to feed children with the family.
NUTRITION IN PREGNANCY
Calorie and protein allowances:
During pregnancy, the mother's diet must
provide the necessary nutrients for the
maternal and fetal tissue formed during
gestation.. These requirements are highest
during the third trimester of pregnancy when
the fetal growth rate is maximal:
Recommended daily allowances for pregnancy
are 30 kcal and 30 g of protein above the
allowances for the non pregnant female.
Recommended weight gain during pregnant
female is 11 kg or more.
The following points are important to consider:
(1) Lower weight gain are associated with lower birth
weight.
(2) Limiting weight gain during pregnancy is indicated in
obese females.
(3) Weight loss is not recommended even for obese
female.
(4) Excess weight gain does not cause pre-eclampsia.
Edema and sodium intake:
Edema is a normal feature of pregnancy and is
associated with higher birth weight, excessive weight
gain as a result of edema is alarming because it could
be a sign of pre-eclampsia, edema alone is not an
indicator for salt restriction or administration of
diuretics.
Complications of diuretics therapy include electrolyte
imbalance, hyperglycemia and pancreatitis in the
mother and hyponatraemia and thrombocytopenia in
the infants, thus in a normal pregnancy sodium
restriction is not indicated and the use of diuretics is
not indicated.
Mineral allowances:
A
decrease
in
hemoglobin
concentration
accompanying pregnancy is due in part to dilution;
adequate iron supplementation will limit the decrease.
0.5 gm of iron is required for maternal erythropoiesis
during pregnancy.
0.3 gm of iron is needed by the fetus thus 0.8 gm of
iron is needed during the second half of pregnancy.
Because of increased absorption and decreased
excretion of calcium in pregnancy as little as 300
mg/day may sufficient, calcium supplementation is
recommended for women who do not drink milk.
Vitamin allowances:
In normal pregnancy folate (folic acid) turnover is
increased in rapidly growing maternal and fetal tissue,
supplement with 200-400 mg/day is recommended. In
spite of its importance in calcium absorption, Vitamin D is
not increased during pregnancy and lactation because an
excess of the vitamin may promote neonatal
hypercalcaemia.
Plasma levels or urinary excretion of riboflavin, thiamin
and vitamin A, C and B12 are low during pregnancy. This
situation is due to dilution and not due to depletion. Since
supplementation does not correct the abnormalities.
Supplementation, therefore is not normally required of
particular importance, is the fact that an excessive intake
of vitamin A may be teratogenic.
Nutritional aspect of lactation
Recommend dietary allowances:
(A) An optimal diet for lactation women furnishes
somewhat more of each nutrient with the exception of
vitamin D, than the amount recommended for non
pregnant female.
(B) Increase are given for energy intake (an additional 500
kcal/day) and protein (an additional 20 g/day.
(C) Food sources, the increased energy and protein needs
of lactation scan be met by drinking less than 1/4 of milk
daily, this will not, however, provide the increased
amounts of ascorbic acid, vitamin D and folic acid
recommended, but this can be taken by adding fruits,
vegetables oils.
(D) Generally, these are not needed except in
situation in which intake of one or more
nutrients is deficient, women who do not drink
sufficient milk may need calcium supplements.
(E) Some physicians advice supplements of iron,
fluoride and vitamin D for breast feed infants.
Nutrition in the adolescent:
• Adolescence is the period of life between the
childhood and adulthood, characterized by a
rapid increase in the rate of physical growth and
changes involving psychological development.
The age at onset range from 9.5-13.5 years.
Adequate nutrition is necessary to provide the
energy and essential nutrients required for
increased linear growth, increase nutrition due
to accelerated growth and development.
Growth, sexual maturation and development during
adolescence:
A.Changes which occur during adolescence include an
increase in the size of every organ except lymphoid
tissue.
•Muscle mass increase in both sexes, but the increase in
the size of male.
•Fat tissues in female during the entire period, but in
males after an initial increase, there is a marked decrease
after 16 years of age.
B. The chronology of sexual development varies
significantly but the sequence is constant.
- Girls: breast enlargement + menarche +weight
gain.
- Boys: testicular enlargement + increase in
height and weight.
Nutritional requirements:
(A)
Basic nutrients:
1- The requirements for calories, protein
carbohydrate and fat are best expressed in terms
of growth rate and state of physiologic
development.
2- To estimate calorie needs, physical activity must
consider.
a. Healthy males (11-14) require 400 calories more
per day than do female of this age group, due to
increased activity.
b. Girls have a peak calorie needs at menarche of
2400 calories followed by a slow decline to 2100
by age old 16.
c. Males consume 2400 calories at age 10, followed by
increase to 3000 calories by age 16.
3-Protein intake is in direct proportion to needs for other
nutrients and should provide 12-15% of the total calorie
intake.
4- Carbohydrate should supply 40-50% calorie intake.
5- Fats should constitute 30-45% of calorie intake.
(B) Calcium requirements:
- With marked bone growth, calcium needs
increase paralleling to increased in calorie intake.
- In both males and females, the calcium intake
increases from 800 mg at 10 years of age to 1200
mg during growth. The primary source of calcium
is milk product.
(C) Iron requirements:
The need for iron is markedly increased during
adolescence in both males and females.
Environmental and psychological influences on diet:
a- There is a poor eating habits results in nutritional
deficiencies.
b- The after school activities need more energy.
c- The decline of family meals, eaten together has been
an advice factor in adolescent nutrition.
d-The teenage tends to buy inexpensive foods.
Nutritional Needs for Adult
Nutrient needs change for both men and women
in the middle-adult years. Energy needs decline
based on loss of muscle mass and low physical
activity. Waist circumference is increase by nearly 1
cm per year over these age range and beyond.
Calcium intakes assume special importance,
particularly for women. Menopause and the loss of
estrogens bring about a decrease in calcium and
absorption and an increase in bone turnover with a
net loss of bone mass and increased risk of bone
fracture.
Dietary Guidelines for Adults
1)Reduce total fat 30% or less calories and
saturated fat to less than 10% of calories
dietary cholesterol to less than 300mg/day.
2) Eat five or more servings of vegetables or
fruits daily.
3) Maintain moderate protein intake, not more
than twice the RDA.
4) Balance food intake and physical activity
appropriate body weight.
5) If you drink alcohol, limit it to no more than two
standard drinks a day.
6) Limit total salt intake to 6 gms a day sodium
chloride.
7) Maintain adequate calcium intake.
8) Avoid eating nutrient supplements with dose above
RDA.
9) Maintain an optimal intake of fluoride.
Nutritional Needs for Old Age
These categories were established to
recognize the physiological changes and
chronic diseases that continue to develop as
we age and influence our nutritional needs.
1) Energy: The energy allowance for older
adults takes into consideration age-related
changes in muscle and active tissue and
expected levels of physical activity. A
physically active 65 year old man weighing
77kg needs about 2600 kcal/day, and a
physically active of this age weighing 57 kg
needs about 2100 kcal/day.
2) Protein: The RDA for protein is the same
for all adult ages 25 and older. A level of
0.8g/kg body weight is recommended for
both genders with reference intake of
56g/day for men and 46g/day for women.
Health status influences protein needs.
3) Minerals: Calcium rises from 1000 mg to
1200mg for persons over age 50 as a strategy
to reduce bone loss, bone fracture, and the
development of osteoporosis.
4) Vitamins: Vitamin needs are unchanged from
middle to older age, except for vitamin B6 and
vitamin D. Vitamin B6 is used less efficiently
by the older adult., so the RDA is higher.
Vitamin B6 is stored and metabolized mainly
in muscle, so muscle loss in older age may
change the body's handling of this nutrient.