Nutrition And Health

This chapter includes :

Section I: Diet Planning Section II: assessment of Nutritional status Section III: Malnutrition

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It is the determination of the quantity & the quality of diet to be consumed by individual.

Factors considered during diet planning

Person

Environment

Constituent of Diet

:Factors to be considered during diet planning A- Factors related to the individuals themselves • Age and Sex • Body weight and surface area: which affect the BMR • Physiological conditions: which reflect the need during growth of the children, pregnancy and lactation. • Level of activities. • Pathological conditions: • BMR decreases in starvation, malnutrition and hypothyroidism • BMR increases in fever (an increase in the body temperature by one-degree increases BMR by 13%).

:B-Factors related to the environment In hot climate, individuals need less calories and .more salts and fluids than in cold ones .In cold regions more caloric food is required

C-Factors related to the diet itself: The food should: - fulfill the qualitative and quantitative requirements of the individual. - be palatable and satisfy the food habits of the individuals. - be variable from meal to meal - be free from infectious agents and toxins. - be digestable and of sufficient size to allay hunger.

- Its nutrients should be of certain proportion to get best benefit. Examples: - Less fat intake affects the absorption of fat soluble vitamins. -Vitamin C facilitates iron absorption -vitamin D facilitates calcium absorption.. - Excess sugar causes dental carries.

Methods of diet Planning: Quantitative Method Qualitative Method.

Quantitative Method of diet planning: Determine the daily caloric requirements: Energy is important for body function &growth. There should be an energy balance between energy intake and energy output. Energy imbalance leads to malnutrition in the form of under nutrition or over nutrition. The energy value of foods is expressed in terms of kilocalories (Kcal). The dietary sources of energy are fats, carbohydrates and proteins

They supply energy at the following order:

One gm. Fat

9 kcal/g

One gm Carbohydrate 4 kcal/g One gm Protein

4 kcal/g

The energy requirement of an individual is defined as: the amount of energy that an individual takes from food in order to keep healthy and active.

Energy is required for: 1. The basal metabolism 2. Daily activities e.g. walking, sitting, standing, dressing, climbing stairs… etc. 3. Occupational work; light, moderate and heavy work.

Energy for basal metabolism The basal metabolism is the energy expenditure of a person who is completely at rest (relaxed and comfortable) i.e. not moving at all, in the morning soon after awaking and 14 hours after the last meal. It is constant per square meter surface area per hour. The average BMR: - for adult man is 40 kcal /square meter surface area / hour. - for adult woman is 37 kcal / square meter surface area/ hour. It can also be assessed by using body weight, where the BMR is 1 kcal /one kg body weight / hour.

Daily Energy requirement For ages over 10 years It is based on the levels of activity people or occupation during 24 hours. These are called Physical Activity Levels (PAL).

Daily energy requirement = BMR x PAL

Physical activity levels (PAL) for women and men aged 18- 60 years Level of physical activity ((PAL

Light

Moderate

Heavy

Women

1.56

1.64

1.82

Men

1.56

1.78

2.10

Examples of occupations for each physical activity level PAL

Typical occupation

Light

People working in offices, students, and unemployed

Moderate

Shop assistants, domestic servants, housewives, drivers

Heavy

Farmers, fishermen, builders, laborers, forestry workers.

For children (0-10 years) . Energy requirement can be calculated using special tables which takes into account energy needed for growth, play and energy to fight infection.

Qualitative Methods of diet planning:

A high quality diet is the balanced diet which contains a variety of foods that provide energy, amino acids, vitamins, minerals, fats, carbohydrates .

The best combination of foods for a balanced diet is as follows:  65% of kcal comes from carbohydrates  25% of kcal comes from fats (a maximum of one third is saturated fat)  10% of kcal comes from proteins

A balanced diet could be achieved through: Food groups 1-Bone building group ( as milk and milk products cheese and ice-cream) 2-Tissue building group (as meat, poultry, fish, eggs and legumes) 3-Energy group (as foods rich in carbohydrates, fats and oils) 4-Vitality or protective group ( vegetables and fruits)

Food guide pyramid

Dietary requirements Protein Proteins are needed for: 1-Tissue building (growth) and tissue repair 2-Formation of antibodies enzymes, hormones, hemoglobin, glycoprotein etc .

Protein requirement depends on Age: Children need more protein for growth. ( A Child needs 2-3 gms protein/ one kg body weight/ day while adult needs 1 gm protein /kg body weight /day) Sex: Men have more muscle and less fat than women, so they need more protein. Body size: Large-sized people need more protein to replace more cells & tissues Pregnancy &Lactation: A pregnant woman needs extra protein for the growth of the baby and placenta and to increase her own blood and tissues.

Carbohydrates Carbohydrates are required because: 1-They provide the energy . Eating less than 50 to 100 grams of carbohydrates per day will make the body utilizes protein for energy. 3-Carbohydrate intake is important for fat metabolism by the liver.

Fat Fat is needed for 1-Supplying energy where 25% of Kcal are supplied by fats Improve the taste of food, make meal less bulky but- 2 more filling It is essential for absorption of fat soluble vitamins (A-- 3 )D-E-K dehydrocholesterol in the skin is the precursor of 7- 4 vitamin D Supporting the viscera-5

Vitamins Vitamins are substances necessary for the body in a very little quantities. They are essential for growth and the integrity of tissues and metabolism. They are not synthesized in the body with few exceptions:

1- Vitamin D is synthesized in skin by the action of ultraviolet rays on 7 dehydrocholesterol 2-Carotenes are the precursors of vitamin A in the body 3-Vitamin K is synthesized in the intestines

Minerals Such as calcium, iron, iodine, fluorine etc. Deficiencies of minerals produce diseases in man

Iron

(Iron deficiency anemia)

Goiter (iodine deficiency). Fluorine ( dental carries) Calcium ( osteoporosis)

Water

• It constitutes 70% of body weight. • It is the main constituent of all body fluids. • It has a role in all biological processes (digestion, absorption, metabolism, excretion etc.) • The average intake is 2.5-4 liters or more according to weather, activity, occupation and health status.

Vulnerable groups These are groups more liable to different nutritional problems than the general population, due to their physiological status. They include • Pregnant and lactating women. • Infants and growing children. • Adolescents specially girls. • Some industrial workers. • Elderly& sick persons as they need special nutritional attention.

Pregnant and lactating women •They are considered the most vulnerable. •They share their nutrients with their children. •Their BMR increases by 20% and, consequently, their requirements increase. •During pregnancy women need extra kcal •to build up their own tissues, •to build fat stores for making breast milk •to build the baby and the placenta..

•Lactating mother needs more calories, proteins, vitamins, minerals •Two to three months after labor, mother should be back to her pre-pregnancy weight

The recommended dietary intakes Group

Man

Woman

Activities

Sedentary work

Body weight (kg)

Net energy kcal/d

Protein g/d

Fat g/d

Calcium mg/d

Iron mg/d

Folic acid Ug/d

60

2425

60

20

400

28

100

50

20

400

30

100

Moderate work

2875

Heavy work

3800

Sedentary work

50

1875

Moderate work

2225

Heavy work

2925

Pregnant woman

50

+300

+15

30

1000

38

400

Lactation 0-6 months

50

+500

+25

45

1000

30

150

+500

+18

Lactation 6-12 months

:Health consequences of maternal malnutrition :A-Fetal effects • Intrauterine growth retardation • Stillbirth • Low birth weight B- Maternal effects • Maternal depletion syndrome 1- Iron deficiency anemia , 2- protein energy malnutrition, 3-Iodine deficiency disorders 4-Osteomalacia • Maternal infection (puerperal sepsis) • Maternal mortality

Indicators to assess maternal nutritional status 1-Pre-pregnant weight and height This is a factor affecting the size of placenta and hence the weight of the baby. 2-weight gain during pregnancy: wellnourished women gain on average about 12kg during pregnancy. 3- Maternal mortality ratio

Industrial workers Malnutrition of industrial workers may lead to :many health problems as  Deterioration of the worker’s health.  Reduction of productivity.  Increased absenteeism.  Decreased resistance to infections.  Susceptibility to accidents, which is related to deficiency in some nutrients such as vitamin B1.

Factors to be considered in feeding of industrial workers Type of work whether light, moderate or heavy.-1 Sedentary work requires fewer kcal, while heavy .activities require more kcal :Climatic condition. 2 • In hot climate, there is much sweating and water loss, extra fluid and salt intake should be stressed upon. •

In cold environment more kcal are required, so, more fats and carbohydrates, and more frequent meals are needed.

Working condition ( indoor, outdoor, in mines or on. 3 )mountains 4. Exposures to toxic materials and fumes: Minerals, vitamins & proteins are needed as detoxifying nutrients

4. Social background. Migratory workers need special attention. workers are at lower socioeconomic condition having improper food habits and behavior. Thus, they require nutritional education that may be provided in the workplace/ restaurant and / or canteen. 5. Adolescents, working pregnant and lactating women may need special attention as they are vulnerable.