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Basics of
nutrition
The
basic objectives of a food plan are as follows:
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Provides nourishment for normal activity and growth
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Helps attain and maintain normal weight
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Is
easily available and low cost
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Provides satisfaction
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Supplies a balanced daily requirement of:
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Calories
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Carbohydrates, Protein & Fat
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Vitamins & Minerals
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Roughage
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Water
Energy - Food provides energy and other nutrients
essential for vital functions of the body,
during periods of rest, activity,
and growth. The amount of food and
type of food we eat determines
the amount of energy we receive. Excess
unutilised calories are stored in the body as fat for future use.
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Energy is produced by utilization of
food in the body. Calorie is a
measure of heat energy.
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The SI (standard International) unit of energy is Joules (J)
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Physiologically energy is measured as Kilo Joules.
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Physiological Calorie is a Kilo Calorie. But we traditionally
continue to refer to Kilo Calories (Kcal) as Calories (Cal).
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1 Kcal = 4.2 KJ
Carbohydrates -
Carbohydrates are the major source of
energy in the body. Carbohydrates are broken down
to form glucose. It is the main nutrient that
raises blood sugar.
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Sugar (refined carbohydrate)
Sugar, Molasses, Honey
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Starch (complex carbohydrate) Bread,
Chappati, Rice, Dal, Pasta, Potatoes
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Fruits and vegetables
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Milk
1 gm of carbohydrate gives 4 calories.
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Sugars are rapidly
digested and absorbed in the body. They
cause rapid and large increase in blood sugar level.
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Starchy foods like roti, rice, and bread are
not rapidly digested and absorbed in the
body. Blood sugar level does not
increase so rapidly.
Protein - One of
the classes of food that is necessary for growth and repair of
tissues. Found in fish, meat, eggs, milk and some vegetables.
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Proteins provide amino acids -
the building blocks
for body tissues, hormones and other
substances.
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Protein rich foods are eggs, meat, fish, milk,
pulses etc.
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1 gm of protein gives 4 calories.
-
Animal source - provide
better quality protein. Egg, milk, meat,
fish, poultry are protein rich foods from animal source.
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Plant
source –
individually provide less
good quality
protein but when two complimentary
types of plant proteins
are
eaten together
the
quality
improves (dal+roti or dal+rice or iddli).
Pulses,
Cereals,
Nuts are sources of plant protein.
Fats -
Fat is the most
concentrated source of energy
-
Fats
in the diet are:
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Saturated - Ghee, butter, margarine, hydrogenated fat (vanaspati).
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Poly-unsaturated - Safflower oil, sunflower oil
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Mono-unsaturated - Olive oil, groundnut oil, mustard oil, sesame
oil.
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Cholesterol - egg yolk, ghee, butter.
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Trans fatty acid - biscuits, cakes, mixture.
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Oilseeds and nuts - (monounsaturated) - Peanuts, Almonds, Walnut.
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1 gm of fat gives 9 calories.
Vitamins - Vitamins are a group of
organic substances present in minute amounts in food and are vital
for good health.
-
A, B group, C, D, E, K is the different groups of vitamins.
Vitamins can be water or fat soluble.
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When a balanced meal with the correct proportions of
carbohydrates, proteins, fats and plenty of fruits and vegetables
is taken, the body automatically receives all the necessary
vitamins.
Minerals - Minerals like vitamins
are vital for good health and are present in large amounts in the
body (bones, blood). Minerals are part of the food we eat. The
different minerals found in food are - Calcium, Phosphorous, Iron,
Sodium, Potassium, and Magnesium. Each mineral has a specific role
to play in ht e body.
Trace elements - Iodine, Zinc, Copper, Chromium, Manganese,
Molybdenum, Fluoride, Selenium, Cobalt, Silicon, Arsenic, Nickel,
and Vanadium.
Antioxidant – Antioxidants are good for health, they protect
against heart disease and possibly other complications.
"Antioxidant" is a classification of several organic substances,
including vitamins C and E, vitamin A (which is converted from
beta-carotene), selenium (a mineral), and a group known as the
carotenoids. Antioxidants neutralize free radicals by donating one
of their own electrons. Free radicals are the natural
by-products of many processes within and among cells. Free radicals
are also created by exposure to various environmental factors, such
as tobacco smoke and radiation. They cause damage to cells and if
the production of free radicals is excessive it can lead to various
complications like heart disease and cancer.
Antioxidants on the other hand act as scavengers, helping to prevent
cell and tissue damage that could lead to cellular damage and
disease.
Evidence suggests that antioxidants are important to good health.
Eating around 5 servings of fruit and vegetables, a day provides the
necessary antioxidant health benefits to the body.
The different groups of antioxidants are:
Tocopherols – good sources include wheat germ, nuts (almonds,
walnuts and peanuts), seeds, whole grains, green leafy vegetables,
vegetable oil like safflower oil, corn oil and fish-liver oil
Cartenoids – good sources include carrots, squash, broccoli,
sweet potatoes, tomatoes, kale, collards, cantaloupe, mango, peaches
and apricots
Vitamin C good sources include citrus fruits, green peppers,
broccoli, green leafy vegetables, strawberries, raw cabbage and
potatoes.
Flavonoids good food sources are broccoli, pomegranate, lime, soy
bean, oranges, lemons, apples, white grapefruit, onions, and
chocolates
Water - Water is the most essential
nutrient the body needs.
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