Water Inorganic Not energy-yielding Essential

Objectives After reading Chapter 7 and class discussion, you will be able to: –Define terms associated with water and body fluids –Describe the fluid composition of the body –Describe water balance

Objectives Identify sources of water and % of water in selected foods Discuss symptoms of dehydration Apply oral rehydration therapy (ORT) Describe functions of water

Functions of Water Transport Solvent Lubricant Maintain blood volume Body temperature regulation Structural support for molecules Participate in metabolic reactions

Functions of Water Transport –Carries nutrients to the cells and carries away waste materials to the kidneys and out of the body in urine

Functions of Water Solvent –Keeps the following in solution so they can participate in metabolic activities: Minerals Vitamins Glucose Many other small molecules in the body

Functions of Water Lubricant –Acts as a lubricant or cushion around joints; in the eye, the spinal cord –In pregnancy cushions the amniotic sac surrounding the fetus

Functions of Water Maintains blood volume Body temperature regulation –evaporation of sweat from the skim removes excess heat from the body

Functions of Water Structural support –Maintains the structure of large molecules such as protein and glycogen Metabolic reactions –Water participates in every step of the process of converting food to energy and tissue

Body Composition 60%

Water in the Body Nutrient composition of the body –Water = 60% –Fat = 13-31% Male = % Female = % –Carbohydrate, Protein, Vitamins, Minerals, Other = 9 – 27%

Water in the Body Example: 150# body –Water = 90# –Fat = # –Carbohydrate, Protein, Major Minerals = # –Vitamin, Minor Minerals = < 1#

Water In The Body Adult body composition is 60% water; higher in children Water is ¾ of weight of lean tissue Water is ¼ of weight of fat tissue Proportion of water smaller in women, obese, and elderly

Body Fluids Intracellular Extracellular –Interstitial –Intravascular

Water In = Water Out

Water Balance Water losses –Obligatory losses=500cc/day (2 c.) Needed to dispose of body wastes –Insensible losses – lungs, skin Water sources Food sources ( cc) Liquid sources –Water vs. Liquids

Fluid:Nutrient Comparison FluidFree Water (cc)Calories/Protein Water240 cc (100%) 0/0 Juice (Apple)210 cc (88%) 111/0 Whole Milk214 cc (89%) 150/8 Instant Breakfast 217 cc (80%) 250/13 Fruit Beverage Supplement 191 cc (79%) 300/10

Recommended Water Intake 1 cc/kcal (30-35 cc/kg) 6-10 cups per day Adequate Intake (AI): Men=3.7 L/day (about 14 c/day) Women=2.7 L/day (about 10 c/day)

Water Balance Dehydration –See Signs of Dehydration –Treat with Oral Rehydration Therapy Water Intoxication –Hyponatremia –Athletes –Elderly

Fluid And Electrolyte Imbalance Replacing lost fluids/electrolytes –Oral rehydration therapy (ORT) ½ L. boiling water 4 t. sugar ½ t. salt

Coffee vs. Water What about coffee/caffeine? No significant difference in hydration Caffeine naivety Journal of American College of Nutrition 2000, 2003

Objectives After reading Chapter 7 and class discussion, you will be able to: –Define terms associated with water and body fluids –Describe the fluid composition of the body –Describe water balance –Identify sources of water and % of water in selected foods

Objectives Discuss symptoms of dehydration Apply oral rehydration therapy (ORT) Describe functions of water