WATER

     WATER : LARGEST CONSTITUENT OF HUMAN BODY :

%age consistence of water in humans :

• Water is essential for life.
• Without food one can survive for about a month,but in the absence of  water for a few days.
• The significance of water is evident from the fact that it is the largest constituent of the human body
• .More than 60% weight of an adult man is water.
• Women contain 45 to 55% since they have more fat,which is drier(20% water)than muscles(75%)
• Babies contain more water than adults do and the elderly slightly less.
• Most of it(about 55 % ) is held inside the cells as intracellular fluid,while the rest(about 45%)is contained in the extracellular fluid.
• Relatively little,about 7.5% of the total water,is in blood stream that forms part of the extracellur fluid.These fluids are in a dynamic state since they constantly undergo changes in composition.
• Nutrients and oxygen are taken up by the cells that in turn excrete carbon dioxide and other waste materials.
• Inspite of this,composition of various body fluids remains almost constant.

             FUNCTIONS OF WATER IN HUMAN BODY :

Water is required in the body primarily to perform some important functions,as briefly discussed below :

1. As a building material in every cell~~fatty tissues contain 20% , bone 26 % and striated muscles 75% water.
2. As a lubricant in joints and between the internal organ.
3. Help to regulate the body temperature.
4. Serve as a medium for nutrients,enzymes and other chemical substances to be dissolved or dispersed.
5. As a medium for intercellular reactions to take place.
6. As a hydrolyzer.
7. As a transport medium for carrying nutrients to cells and removing wastes from he body.

                          SOURCES OF WATER IN BODY :

There are three major sources of water supply in the body :

A.Daily diet supplies

B.Metabolic reactions

C.Intake of drinks

A.Daily diet supplies :

Daily diet supplies 750ml to 1000ml water(about 25 to 35% of the intake)

B.Metabolic reactions :

Water produced in the body as a result of metabolic activity(utilization of nutrients)supplies from 10 to 15% of the daily intake.this water comes from REDOX reactions.thus,when 1g of carbohydrate,fat,and protein are oxidized in the body,o.6 , 1.07 and 0.41g water is produced,respectively.

 C.Intake of drinks :

Water taken as drinks (drinking water,beverages,fruit juices,tea,coffee,milk etc)account for 50% or more of the daily intake.

                         WATER LOSS FROM THE BODY :

Water loss from the body occurs through

• lungs(with respiration
• skin(as sweat&perspiration)
• kidneys(as urine
• digestive tract(in faeces)

THROUGH LUNGS&SKIN :

Insensible loss,also known as transpiration,occurs both through the expired air and skin.It's rate is associated with temperature and humidity.Almost 400ml water is lost in respiration,while about the same quantity is lost through the skin under all conditions.

losses vary greatly with perspiration depending upon activity,temperature and humidity.this may range from a minimum of 200ml in cool climate to about 4L in hot climate.In hot climates a physical labourer may lose upto 14L water per day.In case of severe perspiration,sodium depletion is very likely to occur.

THROUGH DIGESTIVE TRACT&KIDNEYS :

• A loss of 100 to 200ml occurs through feaces.The major route of water excretion is through the kidneys as urine.The kidneys ilter about 180L water per day.However,water lost through urine varies from 1000 to 2000mL per day.
• Losses are replaced with liberal drinking of beverages.
• When water losses are more through perspiration,drinking water or other beverages containing common salt is advisable to replenish sodium loss.

DIET AND MEAL PLANNING

                      Meal planning :

definition :

          Meal planning is planning what you are going to serve for a certain amount of time, could be a week, could be a day, could be a month. You are organizing the ingredients and recipes. 

Objectives could be 

- To make a cheap meal

- To make a nutritious meal 

- To make a meal suitable for all of the family 

- To make a meal that has each of the 4 main food groups in it (Bread&Cereals, Fruit&Veges, Milk&Dairy Products, Lean Meat& Alternatives (Chicken, eggs etc)) 

- To make meals in advance that can be frozen

Diet and meal planning are the important aspects for the nutritionist and homemaker to maintain variety...

While making diet plan,choices,priorities and likes/dislikes of a person to be considered for sure.Choices of food are influenced by 

• one's health aspects
• social life
• cultural background
• religious beliefs
• geographical location
• availability of a particular food item
• age factor.

As talking about food choices,infants show a natural ability to select foods needed by their body.This is lost as the child grows up.Developing good eating habits benefit a person in the long run.

SOME GUIDELINES FOR GOOD MEAL PLANNING:

Some guideline that maybe followed in meal&diet planning are :

1. Make selection from all food groups in the recommended quantities.
2. Everyday food must be covering all the food groups and must be providing minimum recommended servings from all these.
3. Variety must be provided by swapping different foods to provide both nourishment and change in flavor.
4. Milk group must be included in each meal(one food atleast)
5. Ample foods(especially leafy ones) must be included.
6. Cereals group should not exceed 75% of the total energy requirements.
7. Sugar and fat should not exceed 20% of the total calories requirement.
8. Sugar and fat should be minimum or negligible(like below 5%)
9. Atleast 3 of the 6 food groups must be included in each meal.
10. Besides these,one meal serving should be from protein-rich group(a good source of meal must be included)

Meal planning & economic values and special occasions :

• A good meal plan must avoid unwanted,unappetizing and unsatisfying meals.
• A good meal plan must save both time and money.
• Plan must be in a low budget and less money consuming so that a sufficient and nutritionally balanced diet.
• Seasonal availability of food must also be considered.

Meal planning & different food priorities :

Though basic needs of people is the same but yet there is a great difference in the diet of people from person to person.People have different tastes and need different quantities and ratios of nutrients w.r.t age health and other factors. Like ;

• more milk is needed for the children
• small children need less food as compared to the adults
• weight watchers need the same basic foods with necessary modifications such as use of low fat ingredients
• Geriatrics(elderly people) , bcz of digestive disorders and teeth problems,may require light and soft foods.

"Meal planning", both,a science and an art :

Good meal planning is both a science and an art.

-Inclusion of nourishing foods in the diet is a part of science

-combining of of needed nutritious foods into meals that are attractive and appealing and satisfying is an art.

-The color of the food must be appealing

-Food must be of good taste and of choice

-Food must be safe

-Variety should be there in the diet

-Religious and social customs must be considered.

-Meal planning for working women must take into consideration the time required for preparing the meal and energy requirements.

-Family budget must be considered

Meal planning,while considering family budget :

Meal planning must be done considering family budget.Plan must be prepared so that it should be of benefit for the family and not a burden.

It is often suggested that,

• 20% of the budget should be allocated to the cereals
• 20% for the fruits and vegetables
• 25% for the meat,fist,eggs,poultry,legumes and pulses(proteins)
• 20% for the milk and its products(dairy)
• &  15% for the fats and sweets.

exchange lists :

Exchange lists are available that help to substitute one food item with another with similar composition and nutritional benefits.

Therefore,any food from the given exchange list can be substituted or exchanged for any other similar food in that list.

DIET & BALANCED DIET

                                   DIET :

Diet can be defined as...

1.  food and drink regularly provided or consumed
2. the kind and amount of food prescribed for a person or animal for a special reason

The purpose of the diet is to supply nutrients required for optimal health.Diet comprises the foods actually eaten,usually each day.

The diet must be such that it contributes adequate nutrients in the amounts required by an individual.

if a monotonous diet is consumed over a long period.Balanced diet is,therefore,the solution to good health.

                                 BALANCED DIET:

Balanced diet is one that contains all nutrients in correct proportion required by an individual to promote and preserve good health.

• It should help to achieve and maintain good health.Such diet generally leads to good nutritional status of a person.
• Diet must contain food from each group in proper ratio so that mixed diet from a veriety of sources is eaten in moderation.

For an adult person,a balanced diet consists of,

• two or more portions from protein group
• three or more portions from fruits&vegetables groups
• fats should be eaten in moderation
• cereals should be eaten to satisfy appetite
• most of the dietary intakes should be from dietary sources not the pills,which can only deliver the selected nutrients.

Selection of protein should be made from lean meat,fish,saturated fat and cholesterol in their diet.
A person should avoid use of the visible fat,saturated fat and cholesterol.

The above described diet plan is w.r.t sedentary adults.

NUTRIENTS

                                NUTRIENTS:

The naturally occurring food components that are utilized by the human body and provide nourishment are called nutrients that perform functions such as energy giving,bodybuilding etc.

Food exists in nature as a simple assimilable materials or as complex mixtures of chemical compounds.

This may range from a simple common salt molecule to fruits,cereals and milk...

                  CLASSIFICATION OF NUTRIENTS:

Nutrients are usually classified into two classes,by the nutrients,including

• macronutrients

• micronutrients

MACRONUTRIENTS:

Macronutrients are the nutrients required by the body in large amounts,and are

1. Water
2. Carbohydrates
3. Fats
4. Proteins

Functions of macronutrients:  These *constitute bulk of the diet  * supply energy for body activity  *building blocks needed for growth and maintenance.They also provide compounds that regulate body processes.

MICRONUTRIENTS:

Micronutrients are the ones required in smaller quantities,milligrams(mg),micrograms(µg).These are

1. Vitamins
2. Minerals                     ,.,that catalyse the utilization of the macronutrients...!!!

(W.R.F Elements Of Food And Nutrition by Sir J.A.Awan)

FOOD GROUPS

                                 FOOD GROUPS :

Though there are various criteria for classification of nutrients by the nutritionists for the classification of foods depending upon the objectives of the exercise.

 There are generally two food groups :

• Groups based on functions of food
• Groups based on the consumption of food

1.FOOD GROUPS BASED ON FUNCTIONS :

Foods are requires in the body to provide

• energy.
• promote growth.
• repair worn down body tissues.
• sustain the regulatory processes.

W.R.T functions foods are grouped as :

• Energy giving foods : 1.carbohydrates(e.g.,bead,rice,sugar,honey)   2.fats(butter,vegetable oils)   3.proteins (meat,fish,eggs,pulses)

• Growth & repair : 1.proteins(meat,legumes,milk)  2.mineral elements(fruits,vegetables,salt)

• Protective/regulatory foods : 1.proteins  2.mineral elements  3.vitamins  4.water

2.FOOD GROUPS BASED ON CONSUMPTION ;

Changes dietary habits,life styles and advances in food processing have led nutritionists to develop the food pyramid.Food groups based on consumption are described on food pyramid.

FOOD PYRAMID (w.r.t sedentary adult) :

(graphic description of a healthful diet)

Food pyramid is a graphic description of a healthful diet for a sedentary adult.It consists of six segments representing one food group in each.

Food pyramid is a result of the hard researches of nutritionists and their communication to the graphic designers and communication researchers.
Apex:At the apex,are the recommendations for fats,oils and sweets that should be used in least and less amount.
Below apex:Below this is the meat,poultry,fish,dry beans,eggs,and nuts groups on the left and milk,yogurt and cheese group on the right side.
Even below:Next,below these groups there are fruit group(right) and the vegetable group(left).
Base:The base of the pyramid consists of bread,cereal,and pasta group.

SHORT DESCRIPTION OF FOOD PYRAMID:

• Fats are to be used sparingly,dairy and meat groups are to be 2-3 servings,vegetables an fruits groups are to be 3-5 & 2-4 servings,respectively and the breads group are to be 6-11 servings.
• breads group is the major source source of energy.
• this food pyramid is described w.r.t a sedentary adult.

(w.r.f Elements of foof and nutrition by Sir J.A.Awan)

Introduction to food and nutrition

Definitions of nutrition and food :

If defining as a process,Nutrition is defined as,

                                

The process of consuming,absorbing
and using nutrients needed by the
body for growth,development and 

maintenance of life.





But if

defining as a discipline of science,it is defined as,

The science of food,nutrients and
other substances therein ; there
action and interaction in relation
to health and diseases.


      

Essential requisites :

1. optimal growth and development
2. maintenance of body
3. mental growth
4. withstand ageing
5. resistance to environment and diseases

1.OPTIMAL GROWTH :
achievement of optimal growth and development,reflecting full expression of one's genetic potential.

2.MAINTENANCE OF BODY :
maintenance of structural integrity and functional efficacy of the body tissues necessary for an active and productive life.

3.MENTAL GROWTH :
 sound mental growth

4.WITHSTAND GROWTH :
ability to withstand the inevitable process of ageing with minimal disability and functional impairment.

5.RESISTANCE TO ENVIRONMENT AND DISEASES :
ability to resist the adverse effects of environmental toxins and pollutants and combat diseases.

                                            NUTRITION AS A PROCESS :

If describing as a process,it is a process which by witch individual

• ingests
• digests
• absorbs
• transports    &
• utilizes 

nutrients and disposes off wastes.
It is concerned with all the processes of growth,maintenance and repair of the living organisms that depend upon digestion for food.

                                                           FOOD :

                               food is any solid or liquid which on swallowing can supply one or more of the following:

1. energy for movement and all other activities.

1. materials for growth,repair,regeneration and reproduction.

1. substances to regulate the processes of growth and repair.