What is Nutrition:
"The science of food, the nutrients and the substances therein, their action, interaction, and balance in relation to health and disease, and the process by which the organism ingests, absorbs, transport, utilizes and excretes food substance"
Council on Food and Nutrition of the American Medical Association
There is a overwhelming evidence of the occurrence of chronic diseases like Heart disease, Hypertension, Cancer, Osteoporosis, Obesity in modern society. As these diseases are mainly influenced by your diet, it is very important to have a good knowledge about proper nutrition.
There are bad effects on health by both excess or deficient nutrient/energy intake. Malnutrition can result in either degenerative or acute diseases.
Essential Nutrients:
Carbohydrates
Lipids (Fats and Oils)
Proteins
Vitamins
Minerals
Water
There should be at least 45 essential nutrients in your diet for growth,development and maintenance.
Essential nutrients are important to maintain life, but can not produce in the body or can produce in very little amount. If you omit essential nutrients from your diet you may loss certain aspects of your health. You can regain normal function by restoring the essential nutrient in your diet, but this should be before a permanent damage.
There are nonessential nutrients that body can make those nutrients in sufficient quantities if raw materials are available in required quantities. Eg:- Vitamin D, Certain Amino Acids, some Fatty Acids, Cholesterol
Functions of nutrients:
- Provide energy
- Promote growth and development
- Regulate body processes
Protein, Lipids, Vitamins, Minerals and Water promote growth and development of the human body.
Proteins, Lipids, Vitamins, Minerals and Water important to regulate the body processes.
The body composition of a normal adult male (70 kg)
Water 42 kg
Protein 12 kg
Fat 12 kg
Glycogen 0.7 kg
P 0.3 kg
Ca 1 kg
Mg, Cl, Fe, Zn, Cu, K & Na 0.5 kg
Other 1.5 kg
Chemical composition of an adult human body (%)
O - 65%
C - 18%
H - 10%
N - 3%
Ca - 2%
P - 1%
K - 0.4%
S - 0.3%
Effect of growth on the composition of body:
Fetus
(20 – 25 wk)
|
Full term baby
|
Infant (1 year)
|
Adult man
|
|
Body weight(kg)
|
0.3
|
3.5
|
20
|
70
|
Water %
|
88
|
69
|
62
|
60
|
Protein %
|
9.5
|
12
|
14
|
17
|
Fat %
|
0.5
|
16
|
20
|
17
|
Remainder %
|
2
|
3
|
4
|
6
|
Effect of malnutrition on the composition of body:
Premature baby
|
Full term baby
|
Infant (1 year)
|
Malnourished Infant
|
|
Body weight(kg)
|
1.5
|
3.5
|
20
|
5
|
Water %
|
83
|
69
|
62
|
74
|
Protein %
|
11.5
|
12
|
14
|
14
|
Fat %
|
3.5
|
16
|
20
|
10
|
Remainder %
|
2
|
3
|
4
|
2
|
Effect of obesity on the composition of body:
Adult man
|
Obese man
|
|
Body weight(kg)
|
70
|
100
|
Water %
|
60
|
47
|
Protein %
|
17
|
13
|
Fat %
|
17
|
35
|
Remainder %
|
6
|
5
|
Nutrient requirement is different at different stages of life cycle.
The importance of optimal nutrient intake
The optimal dietary intake of nutrient is important to ensure:
Successful development in utero
Growth and Development
Learning potential
Quality of life
Body function
Successful pregnancies
Adequate milk production for a baby's needs
Expectation of a long and healthy life
Freedom from infections
Resistance to disease and response to diseases
Importance of Vitamin C:
Prevention of scurvy
Aid wound healing
Assists absorption of non-heam iron
Important antioxidant
Cofactor in enzymes
Dietary Recommendations
RDA - Recommended Dietary Allowance
The average amount of the nutrient which should be provided per head in a group of people if the needs of practically all members (95%) of the group are to be met.
Recommended Intake
The amounts sufficient, or more than sufficient for the nutritional needs of practically all healthy persons in a population.
Scurvy was among the first disease recognized as being caused by a nutritional deficiency.
