How Nutrients Become You

Six Nutrient Groups– Carbohydrates– Fats– Proteins– Vitamins– Minerals– Water

Chemistry of Nutrition

Elements-simplest substances Matter-takes up space; is measurable Molecule

– smallest amount of substance with characteristics of the substance

– made of two or more atoms bonded together

COMPOUND is formed when atoms of different elements are bonded together

Functions of Nutrients

Build and repair body tissues– Growth spurts, injuries, illness

Regulate body processes– Circulation, digestion, absorption, metabolism

Provide energy– Fuel– Carbs and fats

Energy Value of Food

Kilocalorie-amount of heat required to raise one kilogram of water one degree Celsius

Kilocalorie=Calories Fats=9 calories/gm Carbohydrates=4 calories/gm Protein=4 calories/gm Alcohol=7 calories/gm (no nutrient value!)

The Process of Digestion

Body breaks down food into simpler substances

Mechanical Digestion-chewing…Chemical Digestion

– Enzymes (protein) cause chemical reactions

GI Tract-25-30’ (mouth to anus)– 5-14 hours from mouth to sm. intestine

Components of GI tract

Mouth-mastication, saliva Esophagus (10 “)

– parallels trachea (epiglottis)– Peristalsis-moves food through

Stomach (3 hours-fats take longest)– Gastric juices: HCl, enzymes, mucous– Chyme– Pepsin begins protein breakdown

GI con’d

Small Intestine (95% digestion occurs here)– 20’ long when stretched…1” diameter– Duodenum(12”)– Jejunum (4 ‘)– Ileum (5 ‘)

Large Intestine (colon)– Little digestion– Water reabsorption– Bacteria work on fiber– Feces pass through rectum and anus

Absorption of Nutrients

Passage of nutrients from digestive to circulatory and lymphatic systems

Water soluble nutrients– Amino acids, monosaccharides, minerals, vitamin

C, B vitamins

Fat soluble nutrients– Vitamins A, D, E, K, fatty acids, glycerol,

monoglycerides

Metabolism

Chemical changes producing energy Energy stored in muscles-adenosine

triphosphate (ATP) Waste products from cell metabolism

discarded through– Kidneys– Lungs– Skin

Factors Affecting Digestion

Eating habitsEmotionsFood allergiesPhysical exercise

Digestive Disorders

DiarrheaConstipation IndigestionHeartburn (GERD)UlcerGallstonesDiverticulosis