This document discusses basic principles of nutritional science. It defines key terms like nutrition, dietetics, and registered dietitian. It explains that nutrients perform three basic functions: providing energy, building tissue, and regulating metabolic processes. Carbohydrates, fats, and proteins are described as the main sources of energy. Vitamins, minerals, and fatty acids help build and maintain tissues. Finally, vitamins, minerals, water, and fiber help regulate chemical processes in the body.

1. Basic principles of nutritional
science
Prepared by:
Dr.Mazen Alshaghdari

2. Outline
 Nutrition & health promotion (basic definitions,
importance of a balanced diet)
 Functions of nutrients in food
 Good nutrition:
1) Optimal nutrition
2) Under nutrition
3) Malnutrition
4) Over nutrition
 Nutrient & food guides for health promotion

3. Basic definitions
 Nutrition: concerns the food people eat and how their
bodies use it.
 Nutrition: is a basic need that must be met for all
clients.
 Nutritional science: comprises the body of scientific
knowledge governing human foods requirements for
maintenance, growth, activity, & reproduction.
 Dietetics: is the health profession responsible for
applying nutritional science to promote human health
and treat disease

4. Basic definitions
 Registered dietitian: clinical nutrition specialist, he has
the major responsibility of nutritional care in patients
& clients.
 Health: is defined as absence of disease, and must
meeting basic human needs (physical, mental,
psychological, & social well-being).
 Wellness: seeks the full development of potential for
all persons.

5. Basic definitions
 Traditional & preventive approach to health:
- preventive approach: involves identifying risk
factors that increase a persons chances of
developing health problem.
- Traditional approach: only attempts change
when symptoms of illness or disease already
exist.

6. Importance of a balanced diet
 Food plays an important role in maintaining good
health and recovering from illness.
 Assessing a patients nutritional status & identifying
nutritional needs are primary activities in the
development of a health care plan.
 Signs of good nutrition: well developed body, Ideal
body weight, height, & good muscle development.
- Appetite, digestion, & elimination are normal.
 Calculation of ideal body weight: depend on height
- Every 60 inch give 100 bounds
- Every 1 inch above 60 we add 5 bound for female, &
6 for male.

7. Functions of nutrients in food
 The nutrients must perform the
following three basic functions within
the body:
1) Provide energy.
2) Build tissue
3) Regulate metabolic processes.

8. Energy sources
 Kilocalorie: is the measure of heat necessary
to raise the temperature of 1L of water 1 °C, 1
kcal= 1000 calories.
 Carbohydrates: such as starches & sugars,
consider primary source for heat & energy, also
may store energy as glycogen.
- Each gram of carbohydrate gives 4Kcal of
body energy (fuel factor).
- In a well balanced diet, carbohydrate should
provide about 45%-65% of the total Kcalories.

9. Energy sources
 Fats: either animal or plants sources,
provide the body secondary, or storage
form of heat & energy.
- Each gram of fat consumed yields
9Kcal.
- Fat should provide no more than 20%-
35% of the total Kcalories.

10. Energy sources
 Proteins: each gram gives 4Kcal.
- In a well balanced diet, protein should
provide about 10%-35% of total Kcal.
- Primary function of protein is tissue
building, some of it may be used for
energy if necessary.

11. Tissue building
 Proteins: dietary protein provides amino acids, which
are the building units necessary for constructing &
repairing body tissues.
 Vitamins & minerals: such as vitamin C which used to
develop cementing intracellular ground substance
(collagen).
- Collagen helps build strong tissue and prevents
tissue bleeding.
- Two major minerals (calcium, & phosphorus): they
help in building & maintaining bone tissue.
- Also iron, which contributes to building the oxygen
carrier hemoglobin in red blood cells.

12. Tissue building
 Fatty acids: derived from fat
metabolism, help build the central fat
substance of cell walls and promote
the transport of fat soluble materials
across the cell wall.

13. Regulation & control
 The multiple chemical processes in the body necessary
for providing energy & building tissue should be
regulated and controlled to maintain a smooth,
balanced operation.
 Vitamins and minerals are nutrients that help regulate
many body processes.
 Vitamins: many vitamins function as coenzyme
factors, which are components of cell enzymes, in
governing chemical reactions during cell metabolism
- Example: B-complex vitamins.
 Minerals: many minerals also serve as coenzyme.
- Example: cobalt, which is a central constituents of
vitamin B12, functions with this vitamin to combat
pernicious anemia.

14. Regulation & control
 Other nutrients: water & fiber consider
regulatory agents.
 Water: basic for our life, providing the
essential base for all metabolic
processes.
 Dietary fiber regulate the passage &
absorption of material through the
gastrointestinal tract.

15. Good nutrition
1) Optimal nutrition: means that a person receives and
uses substances that are obtained from a varied diet
of carbohydrates, fat, proteins, minerals, vitamins,
water, & dietary fiber in ideal amounts for the
specific individual.
2) Under nutrition: suboptimal diet, but this not mean
undernourished, still person can maintain health, but
has a greater risk for physical illness, also
nutritionally deficient people are limited in their
physical work capacity, immune system, function,
and mental activity.

16. Good nutrition
3) Malnutrition: when nutrient & energy intake
insufficient meet day to day needs or added
metabolic stress.
- Mostly we see in poor society. -
Vulnerable persons: pregnant women, infants,
children, & elderly adult).
4) Over nutrition: excess nutrient & energy intake
over time
- Harmful gross body weight: morbid obesity.

17. Thank you for listening