Ch. 12 Water and Hydration

Question 1

Discuss the importance of water. What are some key functions? What are sources of water? How is water lost from the body?

Answer 1

Water is a nutrient class and is essential to life.

60% of an adult male’s and 50% of an adult female’s body weight is water
–> body water declines w/age, below 50% in older adults (65+)

Fxn: Water supports good health. Physical and mental performances depend on it, as does the optimal functioning of the GI tract, kidneys, heart, and other body systems.

Sources: liquids (not ETOH), food, metabolic water

Lost from body: kidneys, skin, lungs, feces

Question 2

Explain thirst. How does it relate to the body’s need for fluids?

Answer 2

Def: conscious desire to drink; lags behind body’s need to drink

Thirst is a mechanism to remind yourself that you should be drinking. But you really should be drinking before you get thirsty.

Question 3

Discuss fluid balance. What are sources of hydration and how much do these sources typically contribute? How much fluid is lost from the body and how much do these contribute?

Answer 3

Def: maintenance of the proper types and amounts of fluid in each compartment of the body fluids.

Sources of hydration (mL/d):-

• liquids (550-1500)
• -food (700-1000)
• -metabolic water (200-300)
• -TOTAL: 1450-2800

Output (mL/d):

• -kidneys (500-1400)
• -skin (450-900)
• -lungs (350)
• -feces (150)
• -TOTAL: 1450-2800

Question 4

Identify caffeine sources in the diet.

Answer 4

Coffee (includes decaf)
Tea
Soft drinks
Chocolate
Certain frozen desserts
Energy drinks
Certain candy/bars

Question 5

Is ETOH a source of fluids?

Answer 5

No! ETOH should NOT be used to meet fluid needs.

Question 6

Is caffeine a source of fluids?

Answer 6

Yes, because caffeine has a diuretic effect

Question 7

Do adults require 8 glasses of water a day?

Answer 7

No. There’s no scientific evidence proving the necessity of 8 cups of water/day

Question 8

How many ounces equals cc? How many cc equals mL? Cups to cc?

Answer 8

1cc = 1mL

1 oz = 30cc = 30 mL

*multiply ounces by 30 to get cc and mL [since 1 oz = 30cc or 30 mL]

1 cup = 240 cc

Question 9

How much fluid do I need? (2 methods)

Answer 9

METHOD 1: based on energy intake
o 1ml/kcal/day (healthy adults)

METHOD 2: body weight/age
o	Young adult (16-30yr): 35-40 mL/kg
o	Avg adult: 30-35 mL/kg
o	Adult, 55-65: 30 mL/kg
o	Adult >65: 25 mL/kg

Question 10

What’s dehydration? Symptoms?

Answer 10

Def: from water deprivation or excessive water loss

Symptoms: thirst, weakness, exhaustion, delirium, death

Question 11

What’s water intoxication? Symptoms?

Answer 11

Def: excessive ingestion (intaking insane fluid amounts)

Symptoms: confusion, convulsions, coma, death

Question 12

Fluid Output: Sensible Losses vs. Insensible Losses

Answer 12

Sensible Losses:

• Fluid loss that can be measured
• Loss through urine excretion, feces

Insensible Losses:

• Fluid loss that can NOT be easily measured
• Loss through sweat, respiration