This document discusses the definitions of diet and nutrition. It defines diet as the sum of food and drinks habitually consumed by a person and the circumstances connected to eating. Nutrition is defined as the process of taking in food and using it for growth, metabolism, and repair. It involves ingesting, absorbing, assimilating, and excreting nutrients from food. The document outlines the different types of nutrients found in food including carbohydrates, proteins, fats, vitamins, minerals, dietary fiber, and water. It provides recommendations for a balanced diet including consuming a variety of foods to meet daily recommended allowance levels.

2. Dr Santosh Mahajan (Prof. and Head)
Deptt Biochemistry

3. Does
diet and nutrition
mean
the same?

5. Origin of the word Diet
• The word diet actually comes from the Greek
word “diaita,” which means
“Way of Life.”

6. Definition of diet
Diet is defined as
• The Sum of the food / drinks habitually consumed by
a person or a group daily and also the mental and
physical circumstances connected to eating.
• Diet varies between different countries in the world.
• a healthy/balanced/varied diet
• Rice is the staple diet (= most important food) of many
people in China.
• The children seem to exist on a diet of fried food.

7. Meaning of the word diet
It has different meaning
• As noun:
1 kinds of food that a person, animal, or community
habitually eats.
eg ”a vegetarian diet”
2 A particular selection of food designed or
prescribed to improve person’s physical condition
or to loose or gain weight.
eg diet low in sugar, fat, carories, high protein diet,
liquid diet,, ketogenic diet, etc
• As a verb: dieting (restriction of food intake to
loose weight)

8. • For many people, diet means following a
specific food plan to lose weight. Once the
weight is lost, they go back to their old eating
habits

9. Types of diet
• Healthy diet
• unhealthy diet
and it depends upon
• The way it is cooked, stored, and the type of
nutrients it has

10. Healthy diet
Diet containing milk and milk products, whole grains, pulses,
fruits, fibrous food and food low in cholesterol constitutes the
healthy diet.

11. Unhealthy diet
Sugary drinks, pizza, white bread, fruits juices(due to
more sugar) , cakes, fried, overcooked and undercooked
food constitute unhealthy food.

12. Classification of food
Food is divided into two categories on the basis
of its origin as
1 Animal food
2 Plant food

17. Definition of Nutrition
• Basic definition:
The process of taking in food and using it for growth,
metabolism, and repair.
It involves more than simply eating a “good” diet—it is about
nourishment on every level.
• Scietific definition:
Nutrition is the biochemical and physiological process by
which an organism uses food to support its life.
It includes ingestion, absorption, assimilation, biosynthesis,
catabolism and excretion.
• The science that studies the physiological process of
nutrition is called nutritional science

18. Nutrients
• nutrient, are the substance that an organism must obtain
from its surroundings for growth and the sustenance of life.
• Two types
• nonessential nutrients : that can be synthesized by the cell if
they are absent from the food.
• Essential nutrients cannot be synthesized within the cell and
must be present in the food.
• In some animals, microorganisms living in the gut may
synthesize essential nutrients, which are then released into
the bloodstream.
• In most living organisms, nutrients provide not only the
energy necessary for certain vital processes but also the
various materials from which all structural and functional
components can be assembled.

19. Types of nutrients
There are more than 40 different kinds of
nutrients in food and these are generally
classified into the following 7 major groups:
• Carbohydrates
• Proteins.
• Fats.
• Vitamins.
• Minerals.
• Dietary fibre.
• Water

20. Macro and micro nutrients
• Carbohydrates , proteins, fats, and fibers
constitutes macro nutrients
• Vitamins and minerals constitutes the micro
nutrients
• Dietary fats are divided in to two groups
Visible fat : present in ghee, butter and salad
oils
Invisible fat : found in milk, fish, nuts ,fried
foods etc.

22. 1. It should be a balanced, well planned diet containing all
essential nutrients.
2. The diet should be simple, locally available, palatable
and digestible.
3. Adequate protein content with essential amino acids
should be supplied. This is achieved by a cereal-pulse
mixture with additional animal proteins, if necessary.
4. Calorie intake should be correct and should balance
energy expenditure.
5. Special care should be taken to see that adequate
quantity of calcium and iron are obtained from the diet.
The absorption of these minerals is reduced by other
factors in Indian diet.
6. Should have variety and should not differ very much
from the habitual diet of the person.
7. Should provide adequate roughage.
Planning of Diet

24. A balanced diet is a diet that contains
differing kinds of foods in certain
quantities and proportions (as per RDA
Values )so that the requirement for
calories, proteins, minerals, vitamins and
alternative nutrients is adequate and a
small provision is reserved for additional
nutrients to endure the short length of
leanness.

25. RDA for the nutrients
• The average daily dietary intake level that is
sufficient to meet the nutrient requirement
of nearly all (97 to 98 percent) healthy
individuals in a group is known as the
Recommended Dietary Allowance (RDA) of
food component

26. Factors affecting RDA/ food
requirement
• The RDA is dependent on
1. the individual varibility (Age, weight, height and
physical activity)
2. the bioavailability of the nutrient in habitual
diet
3. Special demands are made during conditions
such as pregnancy, lactation, infancy, childhood
diseased state when individual needs increased
body building/ protective food

27. RDA for food stuff/day for adults
• Carbohydrates 400g
• Proteins 60g
• Fats 70g
• Vitamins
A 1000 retinol equivalent (5000IU for adult male), 800 RE
(4000IU for adult females)
1 RE= 1 μg retinol; 6 μg βcarotene, 12 μg other carotenoids
1 IU = 0.3 μg of retinol
D 5 μg
E 10 mg
K 70-140 μg
B1 1- 1.5 mg
B2 1.2 -1.7mg
B3 15- 20 mg
B6
Biotin (B7) 100-200 μg
Pantothenic acid 5-10 mg
Folic acid 100 μg (300 μg durind pregnancy, 150 μg during lactation)
B12 0.5-1.5 μg (4 μg during pregnancy and lactation)
Vitamin C 60-70 mg

28. RDA for Minerals
• Calcium 800-1200 mg
• Phosphorus 800-1200 mg
• Iron 10 mg

29. Caloric requirement for Indians by Nutrition Expert Group
constituted by ICMR

30. Energy requirement for a person (55kg
doing moderate activity
is calculated by taking into account
• BMR of the person
• SDA( specific dyanamic action) of the
food
• Physical activity of the person
E (kcal/day) = BMR+ SDA+ Physical
activity

31. BMR
• BMR (basal metabolic rate)= (1kcal/kg/h)
The minimum amount of energy required to maintain life
at complete physical and mental state of rest in the post
absorptive state
In males 1600cal/day
Females 1400 cal/day
A BMR value between -15% and + 20% is
considered normal
And is

33. BMR Increases during
hyperthyroidism,
Fever ,
infections,
cardiac failure,
diabetes mellitus,
Polycythemia
Decreases during
Starvation,
Hypothyroidism
addison diease

34. SDA (specific dyanamic action) of food
• Extra heat produced over and above the calculated caloric
values when a given food is metabolized by the body .
• It is the energy required for digestion , absorption,
transport, metabolism and storage .
• It is called the thermogenic action of the food
• It is different for different food components
• SDA for protein 30%
• SDA for carbohydrates 5%
• SDA for lipids 10%
• For mixed diet 10%
• Thus while planning diet 10% extra calories are added
towards SDA
• Higher value of protein indicates that protein is not the good
source of energy but taken during winters to protect from
cold

36. Calculation for Energy requirement for a person/day
(55kg doing moderate activity)

37. Classification of carbohydrates