- Slides: 21
Water The forgotten nutrient
• Water is an essential nutrient that must be replaced every day. • You may be able to survive 2 -3 weeks without food, without water only a few days.
Vital Functions of Water • Found in every cell in the body. • For most adults, body weight is about 50 -70 percent water. That equals about 10 -12 gallons.
Vital Functions of Water cont. • Body fluids include saliva, blood, lymph, digestive juices, urine, and perspiration. – Water is the main component in each of these fluids. § Your diet must include adequate amounts of water to allow your body to form enough fluids. – Without water intake you cannot produce enough sweat to cool you off so you can get headaches, nausea, or dizziness.
Vital Function of Water cont. • Helps chemical reactions take place. • Carries nutrients to and waste products from cells throughout the body. • Reduces friction between surfaces. • Controls body temperature
Helps with Chemical Reactions • This includes the reactions involved in breaking down carbs, fats, and proteins for energy. • Also includes reactions that results in new compounds like nonessential amino acids. • Water is a reactant in many chemical reactions in the body. – A reactant is a substance that enters into a chemical reaction and is changed by it.
Transports Nutrients & Waste Products • Water is a solvent. –Solvents are liquids in which substances can be dissolved. –Water can dissolve most substances, including amino acids from proteins, glucose from carbs, minerals, and watersoluable vitamins.
Waste Products • Blood is primarily made of water. • Water also plays a role in removing wastes from the body through perspiration, exhaled water vapor, and feces.
Lubricates Surfaces • Reduces the friction between surfaces. • Water is an excellent lubricant in your body. – The water in saliva lubricates food as you swallow it. – Tears lubricate your eyes. – Fluids surround your joints to keep bones from rubbing against each other. – Cushions vital tissues and organs to protect them from injury.
Regulates Body Temperature • Blood and perspiration are the body fluids responsible for this task. – Normal body temp is 98. 6 F. Temperatures that are above or below this by 5 F can cause serious health problems. – Ex: Your riding a stationary bike and your whole body becomes hot. This is because blood distributes body heat.
Keeping Fluids in Balance • Throughout the body, there needs to be a balance between water intake and water excretion. • Intracellular water is the water inside your cells. • Extracellular water is the water outside your cells.
The Source of the Body’s Water Supply • Most people need 2 -3 quarts of water per day to replace body fluids. • You meet these needs through the liquids you drink and the foods you eat. – Milk, soft drinks, juices, broth, and tea have high liquid contents. – Summer squash, watermelon, butter, and margarine also have water.
• 12% of your water needs are met through metabolism. • When carbs, fats, and proteins are broken down in the body, some water is released.
Bottled VS. Tap • Bottled water sales have increased. • The cost is several hundred times high than tap water. • Bottled water is no healthier than safe, clean, pure tap water.
Why do we buy bottled water? • We think… –It contains more minerals (doesn’t) –Taste better than tap. –Tap has contaminants –What else?
Can you drink too much water?
• Yes! The result is a rare condition called water intoxication. – People who regularly drink excessive amounts of water usually do so because of a psychological disorder. – Drinking lots of water can dilute electrolytes in the extracellular fluid. You can experience headaches, muscle weakness, and death.
How is Body Water Lost? • Occurs naturally as you carry on regular activities throughout the day. – On avg. you lose 2 -3 quarts of fluid each day. – Most fluid is lost through urine. Also through sweat, you lose moisture in your breath as you breathe, and small losses through bowel waste.
Factors that Increase Water Losses • Dry climates • Illness • Exercise • Diuretics –Substances that increase urine production (coffee and soft drinks do this too)
Effects of Water Loss • When you lose water, you lose weight – However the weight you want to lose is fat, not water! – Water weight is quickly regained when fluids are replenished. – If you do not replace water loss you may become dehydrated (lower than normal body fluid levels)
Guidelines • • • Drink 6 -8, 8 oz. glasses of liquids daily Thirst is the first sign you need water When it is hot DRINK WATER! Pregnant women need more water. Dark yellow urine indicates a high concentration of wastes (this is stressful to your kidneys) • Light color urine shows you are drinking enough to keep wastes flushed out of your body.