summary about nutrition

1. Unit 1 Nutrition and Health
Chapter 2 Principles of a balanced diet
Document 1 Food Supplies
 Food diversity
Foods are formed of a limited number of constituents: water, minerals, carbohydrates, proteins and vitamins.
They provide the organism with the needed matter to build cells, enable cells and liberate the energy needed for
cellular activities.
Organic foods are the only one to produce energy.
Document 2 Quantitative Needs, energetic needs
Quantitative needs represent the quantity of organic nutrients that ensures the energy that is spent by the body.
Energy is spent to perform different activities; muscular, digestive, thermoregulation, basal metabolism…
Spent energy is evaluated by the oxygen volume that is consumed. VO2 consumed reflects the respiratory
intensity.
To calculate the energy spent by an individual: Energy expenditure= VO2 consumed x 20 KJ.L-1
where each L of oxygen consumed releases 20 KJ of energy.
The cell uses oxygen to produce energy in the form of ATP .
Basal metabolism: is the minimal energy expenditure that covers the basic functions of the organism; cardiac,
respiratory, nervous, excretive and cellular renewal.
It is evaluated by the VO2 that is consumed by a resting individual who has been fasting since 12hrs, at rest and
placed at a neutral thermal temperature (18ºC).
Bomb calorimeter: is used to evaluate the quantity of energy produced by a 1g sample of food.
The unit of energy is calories (cal.) or Kcal. , but nowadays it is most commonly measured by KJ.
basal metabolism 60٪
physical activity 24٪
thermoregulation 10٪
digestive activity 6٪
The basal metabolism covers 60٪ of
the total energetic expenditures of an
adult individual with moderate
muscular activity

2. Document 3 Qualitative requirements, energetic needs
Qualitative requirements represent the essential substances that the body cannot synthesize, but must obtain
from nutrients.
 Carbohydrate requirements
Carbohydrates mostly under the form of slow sugars must cover more than half of the energetic needs.
Carbohydrates provide have a high energetic value.
 Lipids requirements
Lipids when digested are hydrolyzed into fatty acids (F.As) and an alcohol (glycerol or sterol).
1 lipid molecule H2O 1 glycerol + 3 F.A.s
Fatty acids and glycerol are the source of energy for muscles during endurance (intensive) exercises.
A F.A. is an organic acid, because it contains C and H, of long carbon chain.
Not all acids can be synthesized by the organism. Certain fatty acids must be provided by food and then are
called essential fatty acids.
 Types of fatty acids
1- Saturated fatty acids; simple bonds exist
between carbon atoms.
2- Mono-unsaturated fatty acids; one double
bond exist between two carbon atoms in the
carbon chain.
3- Poly- unsaturated fatty acids; more than
one double bond exist between two carbon
atoms.
 Lipid Cycle

3. Document 4 Qualitative needs, requirements in proteins
Proteins are the structural molecules that are found in muscles, bones, skin, internal organs, blood, hormones
and enzymes. They are the builders of the cells.
Proteins are complex molecules formed of long chains of amino acids (a.a.s) that are the building blocks of a
protein molecule.
Proteins (of animal or plant origin) amino acids of human proteins
1) Structural proteins (skin,
hair, nails...)
2) Functional proteins
(enzymes, hormones…)
Proteins of animals and plants are made up of 20 a.a.s
10 are non-essential a.a.s;that is they are obtained from food diet and 9 of which are essential a.a.s; they aren’t
synthesized by the body and thus must be obtained by food.
Structure of proteins
Amino acids are the building blocks of proteins.
Two a.a.s joined by peptide bond form a peptide.
Many peptides joined together form polypeptide.
Two or more polypeptides bonded to each other produce a protein.
In order for the protein to be functional, it must acquire a three
dimensional conformation that is specific for its function.
How is it possible that various types of proteins are made up of only 20 a.a.s?
The production of different types of proteins from only 20a.a.s, is due to the following:
- Different number of a.a.s
- Different combinations of a.a.s
- Variation in single a.a. or in the position of an a.a. produces completely different protein.
The daily needs of an individual vary with age, sex, and physiological state.
A minimum intake of protein of an individual is 1g.Kg-1.day
 Intake deficiency
This causes a destruction of structural proteins without their development, which leads to loss of
structural muscle tissue.
 Excess intake
This contributes to the formation of reserve of lipids and to insufficient elimination of excessive
products (urea, ammoniac) by the liver and kidneys.
Digestion Synthesis

4. Document 5 Qualitative needs, requirements in vitamins
Vitamins don’t have energetic value, yet they are essential for life. They are diverse and they contribute to the
proper function of the body.
Vitamins are classified into 2 groups:
1- Hydro-soluble (water soluble)
Include vitamin C and vitamins of group B (B1, B2 …B12)
2- Lipo-soluble (fat soluble)
Include vitamins A, D, E and K.
Hydro-soluble vitamins are eliminated from the body in the urine, whereas lipo-soluble ones are stored in the
body, in the case of excess consumption there can be intoxication.
Document 6 Qualitative needs, mineral requirements
 Water requirements
Water is the main component of the human body (60-70٪). It is present in all the structures of the body
and intervenes in the dissolution of several nutrients.
A person can fast for several days, but cannot go more than three days without water.
 Mineral ions requirements
Certain mineral salts such as sodium chloride (NaCl) which is dissolved in water ensure electrolytic
equilibrium, which is an essential condition for the proper functioning of the organism.
The lack of certain materials, such as calcium, phosphorus and iron leads to severe disorders.
Disease Cause Treatment
Osteoporosis
(is a progressive decrease in the
protein mass of bones)
- Age
- Hormonal problems
- Diet rich in calcium
- limit consumption of alcohol
and tobacco
- practice sports
Tooth decay Insufficient intake of calcium
ions
Intake of fluoride
Thyroidism
(it is an increase in the volume
of thyroid gland)
Deficiency in iodine Diet rich in iodine

5. Document 7 Constructing a balanced food ration
1- To ensure the energetic needs
The expenditure of energy varies with age, gender and the physiological state.
Energy expenditure increases with the increase in the intensity of the exercise. (fig. 39, p.34)
Energy expenditure decreases with the increase in age. (fig.40 , p.34)
It is needed to evaluate the needs of an organism, and to bring a sufficient quantity of organic nutrient to
cover them.
 Formula to apply
Formula 4, 2, 1 = CPL
Energetic expenditures are ensured by:
4 portions of carbohydrates equivalent to 55٪
2 portions of proteins equivalent to 30٪
1 portion of lipids to 15٪
Total energetic intake: 55٪ + 30٪ + 15٪ = 100٪
Of this 100٪ of energetic intake, at least 25٪ should be taken by breakfast.
 To ensure all qualitative needs
All nutrients are important for the body.
Food balance should be respected, to avoid an excess in certain nutrients.
𝑏𝑎𝑙𝑎𝑛𝑐𝑒 𝑎𝑛𝑖𝑚𝑎𝑙 𝑎𝑛𝑑 𝑣𝑒𝑔𝑒𝑡𝑎𝑙 𝑝𝑟𝑜𝑡𝑒𝑖𝑛:
𝑎𝑛𝑖𝑚𝑎𝑙 𝑝𝑟𝑡.
𝑣𝑒𝑔𝑒𝑡𝑎𝑙 𝑝𝑟𝑡.
1
𝑏𝑎𝑙𝑎𝑛𝑐𝑒 𝑎𝑛𝑖𝑚𝑎𝑙 𝑎𝑛𝑑 𝑣𝑒𝑔𝑒𝑡𝑎𝑙 𝑝𝑟𝑜𝑡𝑒𝑖𝑛:
𝑎𝑛𝑖𝑚𝑎𝑙 𝑝𝑟𝑡.
𝑣𝑒𝑔𝑒𝑡𝑎𝑙 𝑝𝑟𝑡.
= 1/2
𝑏𝑎𝑙𝑎𝑛𝑐𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑐𝑎𝑟𝑏𝑜ℎ𝑦𝑑𝑟𝑎𝑡𝑒 𝑖𝑛𝑡𝑎𝑘𝑒 ∶
𝑠𝑢𝑔𝑎𝑟 𝑤𝑖𝑡ℎ 𝑟𝑎𝑝𝑖𝑑 𝑎𝑠𝑠𝑖𝑚𝑖𝑙𝑎𝑡𝑖𝑜𝑛
𝑠𝑢𝑔𝑎𝑟 𝑤𝑖𝑡ℎ 𝑠𝑙𝑜𝑤 𝑎𝑠𝑠𝑖𝑚𝑖𝑙𝑎𝑡𝑖𝑜𝑛
= 1/3
 Food fibers
Carbohydrates also include indigestible fibers (cellulose, pectin...). Food fibers don’t have energetic
value, but they improve intestinal transit and give a sensation of satiety.

6.  Food Pyramid
Document 8 The fate of nutrients
The flux of matter throughout the body: