Water

1
Water

• The most critical nutrient but usually the most
  overlooked.

2
The Vital Functions of Water

• Facilitates Chemical Reactions
• Transports Nutrients and Waste Products
• Lubricates Surfaces
• Regulates Body Temperature

3
Facilitates Chemical Reactions

• Most chemical reactions in the body require
  water, like breaking down carbohydrates, fats,
  and proteins for energy.
• Water is a reactant in many chemical reactions in
  the body.
• Water is needed to split the bonds in the starch
  chain and the elements of the water molecule
  become part of the separate glucose molecules.

4
Transports Nutrients and Waste Products

• Water is a solvent.
• a liquid in which substances can be dissolved
• Water can dissolve most substances
• Amino acids from proteins
• Glucose from carbohydrates
• Minerals
• Water-soluble vitamins
• Blood is primarily made of water and is
  responsible for transporting nutrients through
  the body as well as carrying dissolved wastes
  away from the cells
• Water helps remove waste from the body through
  perspiration, exhaled water vapor, feces, and
  urine.

5
Lubricates Surfaces

• Water is a lubricant.
• A substance that reduces friction between
  surfaces.
• The water in saliva lubricates food as you
  swallow it.
• Water acts as a lubricant throughout the
  digestive system to assist the easy passage of
  nutrients.
• Tears lubricate your eyes.
• Fluids surround your joints to keep bones from
  rubbing together.
• Cushions vital tissues and organs

6
Regulates Body Temperature

• Normal body temperature is near 37oC.
  Temperatures that are above or below this can
  cause serious health problems.
• Heat from your body is released when blood flows
  near the surface of your skin.
• Sweat glands produce perspiration. The
  evaporation of water in perspiration helps cool
  your body.
• When your body gets too cold, your blood vessels
  constrict to restrict the amount of blood flowing
  near your skins surface.

7
Fluid balance

• Throughout the body, there needs to be a balance
  between water intake and water excretion.
• Cells are like balloons. Burst or collapse?
• Intracellular water the water inside the cells.
• Extracellular water the water outside the cells.
• Water can move freely across the cell membranes.
• The concentration of sodium, potassium, and
  chloride determines the movement of water.

8
The Source of the Bodys Water Supply

• Most people need about 2-3 liters a day to
  replace body fluids.
• While water is the best source of this nutrient,
  milk, pop, juice, broth, tea, and other liquids
  have a high water content.
• As food contains some water, it also acts as a
  source of water. Example orange juice is 87
  water, while summer squash is 96 water.
• 12 of your water needs are met by metabolism.

9
Bottle Water vs. Tap water

• http//www.youtube.com/watch?v_3QBZac3MSY
• The cost of bottle water can be several hundred
  times higher than the cost of tap water.
• Bottle water is no healthier than safe, clean,
  pure tap water.
• http//www.youtube.com/watch?vJNRgfprf9EM

10
Can you drink too much water?

• Yes! The result is water intoxication.
• Drinking large quantities of plan water can
  dilute the concentration of electrolytes in the
  extracellular fluid. This can cause headaches
  and muscle weakness. Severe cases of water
  intoxication can cause death.
• Infants are at a high risk of water intoxication
  when experiencing diarrhea or vomiting.
• When fluid losses are excessive, both fluids and
  electrolytes must be replaced.

11
How Is Body Water Lost?

• Water loss happens in one of three ways
• Urine
• Sweat
• Breath
• Factors that increase water losses
• Hot or warm temperatures
• Dry climates
• Using diuretics increase urine production
• Caffeine, alcohol
• Illness
• Exercise

12
Effects of Water Loss

• Because fluids make up a high percent of your
  body weight, when you lose water, you lose
  weight.
• Water weight is quickly regained when body fluids
  are replenished.
• When you lose 2 or more of body weight in
  fluids, you will become thirsty.
• If you do not replace water losses, you may
  dehydrated (body contains lower than normal
  amount of body fluids).
• Urine, sweat decreases, concentration of sodium
  in blood increases.
• Athletic performance will go down with a 3 fluid
  loss.

13
Guidelines for Fluid Replacement

• Drink 6-8 8-ounce glasses (1.5-2 liters) of water
  a day.
• If you feel thirsty, drink liquids.
• When the weather is hot, you should make an
  effort to increase fluid intake.
• Begin drinking before you start to exercise.
• Healthy urine output is a minimum of 2 ½ cups a
  day.
• Use the color of your urine to gauge your water
  input Light-coloured urine is what you are
  aiming for, almost clear.

14
People with above average needs for water

• Infants
• Older adults
• Pregnant women
• Lactating women
• People on high-protein diets