Food and Nutrition

Nutritional Requirements

Nutrient are the raw materials, which provide the essential

matter and energy for life.
 Classes of Nutrients

There are six classes of nutrients:

1. carbohydrates,
2. fats (lipids) (20%),
3. proteins,
4. vitamins,
5. minerals, and
6. water (60%).
 Energy Nutrients
Carbohydrates, Lipids and Proteins

❑ Used by body as source of energy.

❑ All these three nutrients are Carbon containing

compounds.

❑ Proteins are not preferred energy source. They are

building blocks to make our body.

❑ Body does not get energy from vitamins, minerals, water.

 Carbohydrates
❑ Fresh fruits, whole grains, and vegetables—especially legumes such as peas
and beans—provide abundant complex carbohydrates.

❑ The body breaks the starch in these foods into glucose, your primary source
of energy. These foods also provide essential vitamins and fiber.

❑ Eating foods high in soluble fiber helps lower one's cholesterol level and may
reduce the risk of heart disease.

❑ A diet high in insoluble fiber helps prevent constipation.

❑ Foods rich in processed carbohydrates such as white flour, refined sugar,

and corn syrup are sometimes said to be "empty calories” This is a way of
saying that these foods provide little in the way of vitamins or fiber.
 Lipids
❑ Body uses lipids to build cell membranes, as energy stores, and as a
reservoir for fat-soluble vitamins.

❑ Linoleic acid and alpha-linolenic acid are essential fatty acids, meaning
the human body needs them but cannot make them.

❑ Mainly 2 types: saturated and unsaturated fatty acids.

❑ Dairy products and meats are rich in saturated fats and cholesterol.
Overindulging in these foods increases one's risk for heart disease, stroke,
and some cancers.

❑ Trans fatty acids, or trans fats, are manufactured from vegetable oils.
Worse for the heart than saturated fats.
 Proteins
❑ Amino acids are building blocks of proteins.

❑ Your cells can make some amino acids, but you must get
essential amino acids from food.

❑ Most proteins in meat are "complete," meaning their amino

acid ratios match a human's nutritional needs.

❑ By contrast, most plant proteins are "incomplete," meaning

they lack one or more amino acids essential for the human diet.
 Vitamins

❑ Vitamins are organic molecules required by the body in small

amounts for metabolism, to protect health, and for proper growth.

❑ Many functions in body.

❑ Required in small amount. But there are 13 essential vitamins for

human. Major ( A, B, C, D, E and K)

❑ They are differentiated according to their absorbency in fat/water.

 Vitamins

1. Fat soluble Vitamins: A, D, E and K

Taken with fat containing foods.
They can remain stored in body fats.
Not necessary to consume everyday.

2. Water soluble Vitamins: B and C.

Cannot be stored.
Need to take frequently/everyday.
 Minerals
❑ Minerals are inorganic substances and are transported around
the body as ions dissolved in the blood and other body fluids.

❑ Different minerals perform different roles in human body.

❑ Example:

✓ Calcium: Helps build up different body structure- bones, teeth etc. and
helps in blood clot.

✓ Sodium: Maintains fluid balance.

✓ Magnesium: Helps in energy release from energy nutrients.
 Water
❖ Water provides the medium in which all the body’s reactions take place.
❖ It aids in the digestion and absorption of food.
❖ It is a medium of transport, through arteries and veins, within an
organism.
❖ It even lubricates your joints and cushions organs such as the brain and
spinal cord.
❖ It helps in the excretion of harmful by-products of metabolic processes.
❖ It aids in the regulation of heat loss.
❖ Key players when bonds are broken (by hydrolysis) or formed (by
dehydration synthesis) in these molecules.
 Food as Fuel: Calories Count
❑ Food energy is usually measured in kilocalories (kcal), also called Calories (Cal).

❑ A large apple contains about 70 Cal worth of energy-producing compounds; and jogging 1.6
km (1 mile) burns about 100 Cal of stored energy.

❑ The food energy in a slice of bread could bring a liter of water to a boil, and a pound of body
fat has enough energy to bring 52 liters (13 gal) to a boil!

❑ Each person has a minimum daily energy requirement that varies with age, sex, body size,
activity level, and other factors.

❑ In general, a normally active female college student needs around 1,800-2,000 Cal a day to
fuel her total metabolic needs; A male college student needs about 2,200-2,500 Cal.

❑ Carbohydrate and protein each provide about 4 Cal/g, while fat provides more than twice as
much, or 9 Cal/g.
 Food as Fuel: Calories Count

Calorie value of food :

a) Carbohydrate - 4.4 cal/g.

b) Fat - 9.3 cal/g.
c) Protein - 4.0 cal/g.

• A person would have to run for about 30

minutes, for example, to burn off the calories in
a cheeseburger.
 Food as Fuel: Calories Count

Intake food (energy nutrients) > Energy needs :

stored in body fat.

Energy need > intake food : burn body fat.

Balanced Diet
Balanced diet is a diet containing all the proximate principles of
food in adequate and proportionate amounts; including essential
amino acids and fatty acids for normal growth, activity,
reproduction.

• Adequate : Means the amount that supply the exact calories.

• Proportionate amount : Means presence of appropriate
proportion of food stuffs.
Criteria of a balanced diet
• Proximate principles of food in adequate and
proportionate amount.
• One third to half of protein
• Fat should come from animal sources.
• Sufficient fruits and vegetables.
• Easily digestible and absorbable food.
• Easily available food.
• Certain amount of cellulose to promote peristalsis.
 Factors considered to formulate a
balanced diet
❖ Age
❖ Sex, height, weight
❖ Quality and quantity of food.
❖ Socio-economical value
❖ Seasonal factor
❖ Geographical
❖ Allergic condition
 Body Mass Index (BMI)

• The body mass index (BMI) or Quetelet index is a

value derived from the mass (weight) and height of an
individual.

• The BMI is defined as the body mass divided by the

square of the body height and is universally expressed
in units of kg/m2, resulting from mass in Kilograms
and height in meters.
Body Mass Index(BMI) count
 Body Mass Index (BMI) count

The correlation between the BMI number and body fatness is fairly strong however
the correlation varies by sex, race, and age.
1. At the same BMI, women tend to have more body fat than men.
2. At the same BMI, older people, on average, tend to have more body fat than
younger adults.
3. Highly trained athletes may have a high BMI because of increased
muscularity rather than increased body fatness.
 Body Mass Index(BMI) count
• BMI is only one factor related to risk for
disease, For assessing someone's likelihood of
developing overweight- or obesity-related
diseases

1. The individual's waist circumference

(because abdominal fat is a predictor of
risk for obesity-related diseases).

2. Other risk factors the individual has for

diseases and conditions associated with
obesity are for example, high blood
pressure or physical inactivity.
Body Mass Index
 How To Calculate How Many Kilocalories You Need
1. Multiply the weight (in pounds)
by 10 if you are not active physically,
by 15 if you are moderately active, and
by 20 if you are highly active

2. Subtract one of the following amounts from the multiplication result

 How To Calculate
How Many Kilocalories You Need
• For example, if you are 25 years old, are highly active, and
weigh 120 pounds, you will require 120 X 20 = 2,400
kilocalories daily to maintain weight. If you want to gain weight
you will require more; to lose, you will require less. The amount
is only a rough estimate.
• Other factors, such as height, must be considered. A person 5
feet, 2 inches tall and active does not require as much energy as
an active 6-footer whose body weight is the same.
How to read food labels
 Malnutrition
❑ Malnutrition refers to insufficient, excessive, or imbalanced consumption of
nutrients by an organism.

❑ In developed countries, the diseases of malnutrition are most often associated

with nutritional imbalances or excessive consumption.

❑ Although there are more organisms in the world who are malnourished due to
insufficient consumption, increasingly more organisms suffer from excessive over-
nutrition; a problem caused by an over abundance of sustenance coupled with the
instinctual desire (by animals in particular) to consume all that it can.
What is Diabetes Mellitus?
Causes of Hyperglycemia
 If insufficient/lack of insulin

Glucose can’t enter the cell

Glucose remains in blood

Diabetes Mellitus/Hyperglycemia
Types of Diabetes
There are mainly three types of diabetes:

❑ Type I or insulin dependent diabetes often called juvenile onset

diabetes,

❑ Type II or non-insulin dependent diabetes often called adult-onset

diabetes & Gestational diabetes.

• The most common forms of diabetes are type 1 diabetes (5%), which is
an autoimmune disorder and type 2 diabetes (95%), which is associated
with obesity.

• Gestational diabetes is a form of diabetes that occurs during

pregnancy.
Type I & II Diabetes : Insulin Response

Here, insulin is
In Type I diabetes, present, but signal
This is a normal
insulin is not for proper glucose
cell.
produced; so, uptake & metabolism
Insulin is present
there is nothing is lost. The problem
and is taken into
to signal the could be in the insulin
the cell to
cells to take in itself or in any one
facilitate proper
glucose of the proteins involved
glucose uptake.
and metabolize it. in glucose uptake and
metabolism.
Gestational Diabetes- 3rd Type of Diabetes
Gestational diabetes is diabetes that happens for the first time when a woman is
pregnant. Gestational diabetes goes away when any woman has her baby, but it
increases her risk for having diabetes later.
Due to Gestational Diabetes, the baby has risks for-

1) Macrosomia - refers to a baby that is considerably larger than normal.

2) Birth injury - may occur due to the baby's large size and difficulty being
born.

3) Hypoglycemia – refers to low blood sugar in the baby immediately after

delivery.

4) Respiratory distress- difficulty in breathing.

 Signs & Symptoms
Sudden
Weight
Loss

gulp
gulp
gulp
Always
Dry Mouth Hungry
Extreme Thirst

Frequent Urination
Always Tired
Wounds that
won’t heal
Frequent Bed wetting Stomach Pain
 Diagnosis
Diabetes is diagnosed by
Blood Glucose
measuring the blood glucose (mg/dL)
Category
level during fasting (Fasting Fasting After meal
plasma glucose test) or an oral Normal <115 <140
glucose tolerance test. Diabetic >140 >200
Three status associated with Impaired
diabetes: people who are not Glucose <140 140-199
Tolerance
diabetic; those with Impaired
Glucose Tolerance (IGT); and
those with diabetes.
Lipid profile
What is a lipid profile?

The lipid profile is a group of tests that are often ordered together
to determine risk of coronary heart disease.

The tests that make up a lipid profile are tests that have been
shown to be good indicators of whether someone is likely to have
a heart attack or stroke caused by blockage of blood vessels
(hardening of the arteries).
What tests are included in a lipid profile?

The lipid profile includes total cholesterol, HDL-cholesterol

(often called good cholesterol), LDL-cholesterol (often called bad
cholesterol), and triglycerides.

Sometimes the report will include additional calculated values such

as the Cholesterol/HDL ratio or a risk score based on lipid profile
results, age, sex, and other risk factors.
❑ Cholesterol helps the body form hormones, vitamin D and
other important substances, but too much of it in the blood can
clog and damage the blood vessels. Because it is a fat-like
substance that doesn't mix with blood, cholesterol has to combine
with proteins to form lipoproteins. Lipoproteins can travel in the
blood to all the organs and tissues of the body.

❑ Low-density lipoproteins (LDLs, or "bad" cholesterol) build

up in the blood and increase your risk of heart disease.
❑ High-density lipoproteins (HDLs, or "good"
cholesterol) carry cholesterol to the liver, where it is removed
from the body.

❑ Triglycerides store energy for your body to use when it is

needed. If there is too much, it can block blood vessels and
cause other health problems such as abdominal pain and
pancreatitis.
It's important to know the ranges....

• Total Cholesterol (lower is better)

Best = <200 mg/dL
Borderline high = 200-239 mg/dL
High = 240 mg/dL or higher

• Triglycerides (lower is better)

Best = <150 mg/dL
Borderline high = 150-199 mg/dL
High = 200-499 mg/dL
Very high = 500 mg/dl or higher
• LDL Cholesterol (lower is better)
Best = <100 mg/dL
Good = 100-129 mg/dL
Borderline high = 130-159 mg/dL
High = 160-189 mg/dL
Very high = 190 mg/dL or higher

• HDL Cholesterol (higher is better)

Low = <40 mg/dL
Best = 60 mg/dL or higher