2. INTRODUCTION TO HUMAN
NUTRITION
Presented By: Ms. Hafiza Madiha Jaffar
Clinical Nutritionist

3. DEFINITIONS
Food: any substance, solid or liquid, that contains
nutrients, which meets the needs for energy, building,
regulation and protection of the body.

4. CLASSIFICATION
Classification by origin: -
• Foods of animal origin
• Foods of vegetable origin
Classification by chemical composition:
• Proteins
• Fats
• Carbohydrates
• Vitamins
• Minerals

5. DEFINITIONS
• Nutrition is the study of nutrients in food, and the relationship
between diet, health, and disease.
• Is the process of consuming, absorbing and using nutrients
needed by the body for growth, development and maintenance
of life.
• Human nutrition deals with the provision of essential
nutrients in food that are necessary to support human life and
health.
• Nutrition science deals with the role of food (dietary inputs)
in the maintenance of life.

6. DEFINITIONS
• Diet refers to whatever you eat and drink each day.
• Balanced diet: contains all the nutrients in the correct
amount for the needs of the body.
• Recommended dietary allowance (RDA): the
amount of the nutrient we should eat each day
• Deficiency disease: ill effects that are caused by lack
of the nutrient

7. NUTRIENTS
Nutrient is any substance which can be digested and
used by the body.
Or
Organic and inorganic complexes contained in food
are called nutrients.
They are broadly divided in to:

8. TYPES OF NUTRIENTS
Macronutrients:
• Nutrients required in relatively large amounts.
• Provide energy to our bodies
• Carbohydrates, fats and oils, proteins
Micronutrients:
• Nutrients required in smaller amounts.
• Vitamins and minerals

9. ENERGY FROM NUTRIENTS/ DAILY
CALORIC INTAKE
• Your body’s energy needs are measured in calories.
• A calorie is the amount of energy needed to raise the
temperature of 1 kilogram or water 1 degree Celsius.
• You expend calories with everything you do.
• On food labels “calorie” refers to kilocalories.

10. HOW MANY CALORIES SHOULD I EAT?

11. WHY IS IT IMPORTANT TO EAT HEALTHY?
• Best way to live a healthy life is to eat a balanced diet
• To provide nutrients that your body needs to function like
provide energy, building the body and regulate activities
of the body.
• To give you more energy and alertness throughout the day
• To prevent future disease and sickness like Diabetes,
obesity and cancer etc.

13. SCOPE OF FOOD
& NUTRITION
• FOOD CHEMIST
• SPORTS
NUTRITIONIST

14. MALNUTRITION
• Health as the ‘state of complete physical, mental and social
well-being and not merely the absence of disease’
• Malnutrition is defined as "lack of proper nutrition, caused by
not having enough to eat, not eating enough of the right things,
or being unable to use the food that one does eat". or
imbalance of nutrients in the diet. It includes undernutrition
and overnutrition.
• Undernutrition is a state of an insufficient supply of essential
nutrients.
• Overnutrition refers to an excessive intake of one or more
nutrients, which creates a stress in the bodily function.

15. STEPS OF NUTRITION
• The use of food in the body involves three processes — ingestion,
digestion, absorption and utilization of nutrients in the body.
• Digestion is the process, which releases many nutrients in the
forms the body can use, by breaking up food in the intestinal tract.
e.g. carbohydrate into glucose, proteins into amino acid and lipids
into fatty acid
• Absorption is the process which carries these nutrients into the
circulation system and delivers them to the cell.
• Utilization. Cell is the functional unit of life. Hence many the
chemical reactions in the cell utilize the nutrients absorbed to
produce materials needed for our existence.

16. STEPS OF
NUTRITION

18. DIFFERENCES BETWEEN MACRO-
NUTRIENTS AND MICRO-NUTRIENTS
S.N.
Difference on the
basis of
Macro-nutrients Micro-nutrients
1.
Requirement
Macro-nutrients are required in larger
amount/quantity on daily basis
Micro-nutrients are required in small or tiny
amount/quantity on daily basis
2.
Function
Macro-nutrients is essential for
growth, repair and develop new
tissues (carbohydrates), maintain
body temperature (fats), conduct
nerve impulses, and regulate life
process.
Micro-nutrients support macro-nutrients to
carry out bodily functions. They are also an
essential component for building healthy
brain, body and bones.
3.
Benefits/advantages
· Macro-nutrients contribute to the
bulk energy needed for the metabolic
system.
· Macro-nutrients provide calories
that gives energy to the body
· Micro-nutrients contribute to body
growth and disease prevention.
· Micro-nutrients comprises of high
volume of antioxidants which protects the
body against various diseases
4.
Role
Macro-nutrients plays a vital role in
the construction of body composition.
Micro-nutrients do not have any role in the
construction of body composition.
5. Macro-nutrients are available in high Micro-nutrients are present in minute

19. 6. Composition/k
nown as
Macro-nutrients are also called as major
elements.
Micro-nutrients are also called trace elements.
7. Food
composition
Cereals, legumes, meat, fish, yams,
potatoes, nuts, oilseeds are rich in
macro-nutrients.
Mainly vegetables, fruits, eggs, green leafy
vegetables, fermented foods are rich in micro-
nutrients.
8. Types and
examples
There are mainly three macro-nutrients
required by the body; carbohydrate,
protein and fats
Different types of micro-nutrients required by the
body include vitamins, minerals and trace
elements. Examples: iron, magnesium, calcium,
phosphorus, zinc etc.
9.
Quantity
Macro-nutrients are divided into two
classes: Primary and Secondary, as
they are required in large quantities.
Micro-nutrients are not classified in different
types, as it is required in trace amount.
10. Toxicity
Macro-nutrients are normally not toxic to
the cell if they are present in
comparatively higher concentration than
in the normal level.
Micro-nutrients are toxic if present hugely in the
cell than the required amount.
11.
Excessive
ingestion
Excessive intake of micro-nutrients
leads to obesity and diabetes.
Excessive consumption of micro-nutrients leads
to suppressing immune function.

20. 12.
Consequenc
es of
deficiency
Deficiency of macro-nutrients causes Protein
Energy Malnutrition (PEM), Kwashiorkor,
marasmus etc.
Deficiency of micro-nutrients causes
different diseases like night blindness,
beriberi, scurvy, goiter etc.
13.
Consequenc
es of
overdose
Overdose of macro-nutrients causes obesity,
heart diseases, diabetes and other metabolic
syndromes
Overdose of micro-nutrients may harm
specific organs of the body. E.g.:
overdose of vitamins affect liver
14.
Daily
recommend
ed
requirement
s
· From carbohydrates: 55–75% of total energy
· From protein: 15-20% of total energy or 1g/kg
body weight per day
· From fats: 20-35% of total energy
· From monounsaturated fats: 20% of total
energy
· From polyunsaturated fats: 10% of total
energy
· From saturated fats: 7% of total energy
· Vitamin A – 700 µg
· Vitamin B12 – 2.4 mg
· Vitamin E – 15 mg
· Vitamin C – 75 mg
· Thiamine – 1 mg
· Riboflavin – 1.1 mg
· Niacin – 14 mg
· Folate – 400 mg
· Iron – 18 mg
· Selenium – 55 mg
· Calcium – 1000 mg

21. OVERVIEW OF
MACRONUTRIENTS

22. CARBOHYDRATES
They are required for energy and provide body’s main source of
energy; they form the major part of stored food in the body for later
use of energy and exist in three form:
• Sugar
• Starch
• Fiber
The brain works entirely on glucose alone. When in excess, it is
stored in the liver as Glycogen. Carbohydrates are also important for
fat oxidation and can also be converted into protein.

23. RECOMMENDED ALLOWANCE
• Sedentary Individuals: 40-50% of your total daily
calories should be carbohydrates
• Exercises Regularly: 60% of your total daily calories
should be carbohydrates
• Athletes or persons involved in heavy training: 70% of
your total daily calories should be carbohydrates (3.5-
4.5 grams of carbohydrate per pound of body weight)
• NOTE: 1 gram of carbohydrate = 4 Calories

24. Food Sources
• Grains (choose mostly whole grains for added
benefits)
• Dairy (choose low-fat or non-fat most often)
• Fruit (choose whole fruits more often than fruit
juices)

25. PROTEINS
They provide amino acids and make up most of the
cell structure including the cell membrane. They are
the last to be used of all macronutrients.
In cases of extreme starvation/ hunger, the muscles in
the body, that are made up of proteins, are used to
provide energy. This is called muscle wasting.

26. RECOMMENDED DAILY ALLOWANCE
• Sedentary Individuals: 0.36 grams of protein per pound of body
weight
• Active: 0.45-0.68 grams of protein per pound of body weight
• Competitive Athlete: 0.54-0.82 grams of protein per pound of
body weight
• Teenage Athlete: 0.82-0.91 grams of protein per pound of body
weight
• Body Builder: 0.64-0.91 grams of protein per pound of body
weight
• NOTE: 1 gram of protein = 4 Calories

27. FOOD SOURCES
• Legumes (beans)
• Lentils
• Peanuts and nuts
• Whole grains (quinoa, oats, brown rice)
• Seeds
• Meat alternative products
• Some vegetables
• Animal sources

28. FATS
Fats are used in making steroids and hormones and
serve as solvents for hormones and fat-soluble
vitamins. Fats have the highest caloric content and
provide the largest amount of energy when burnt.
Extra fat is stored in adipose tissue and is burnt when
the body has run out of carbohydrates.

29. FATS
Role in the Body
• Energy reserve
• Protects vital organs
• Insulation
• Transport fat soluble vitamins
Recommended Allowance
• 20-35% of your total daily calories should come from fat Less than 10%
of total daily calories should come from Saturated Fat (coconut oil, butter,
cream cheese, full fat dairy products)
• NOTE: 1 gram of fat = 9 Calories

30. FOOD SOURCES
• Oils
• Nuts
• Seeds
• Meat, fish, dairy

31. EFFECTIVE NUTRITIONAL PLAN
• Breakfast is the most important meal of the day.
• Attempt to eat 4-6 meals per day.
• Minimum of 8 glasses of water per day.
• Attempt to consume carbohydrates, proteins, and fats in
every meal.
• Vegetables are the best source of vitamins and minerals.
• Read labels and understand serving sizes.
• Supplements should be used as supplements.

32. REFERENCES
• https://www.publichealthnotes.com/15-differences-
between-macro-nutrients-and-micro-nutrients/
• http://mynutrition.wsu.edu/nutrition-basics#carbo