How Nutrients Become You Chapter 3

Food, Nutrients, and Energy The Six Nutrient Groups They are carbohydrates, fats, proteins, vitamins, minerals and water. Must obtain from foods you eat. Each nutrient has a specific job to perform in the body/vital to good health. The Chemistry of Nutrition Terminology Elements, Matter, Atom, Molecule, Compound

Food, Nutrients and Energy The Functions of Nutrients Build and Repair Body Tissues Nutrients needed during periods of growth Periods are; Prenatal, Infancy and Adolescence. Good Nutrition needed to reach your full genetic potential. Regulate Body Processes Following Processes need balance of essential nutrients: circulation of body fluids, digestion, absorption and metabolism. Chemical reactions that control body processes are maintained by nutritious food. Provide Energy Food is the source of energy for your body. Quality of food affects how well your body will run. Need energy for all life processes. Two main nutrients needed for energy are carbohydrates & fats. Using protein for energy is like burning the house to keep it warm. The Energy Value of Food Energy value of food is measured in kilocalories calories) – the amount of heat needed to raise one kilogram of water one degree Celsius. 1 gram of carbohydrates =4 calories, 1 gram of fat 9 calories, 1 gram of protein =4 calories.

The Process of Digestion Digestion-the process by which your body breaks down food, and the nutrients in food, into simpler substances. Mechanical Chemical In the Mouth Mastication or chewing is first step. Chew food well-it aids in digestion. Taste buds Salivary glands – produce saliva a mixture of about 99% water plus a few chemicals. Keeps mouth moist, gives food taste, moistens, softens and dissolves food, helps cleanse teeth and neutralize mouth acids.

Process of Digestion In the Esophagus In the Stomach Passageway from the mouth to the stomach. Tube about 10 inches long Breathing automatically stops when you swallow to prevent choking. Squeezing motions in the esophagus called peristalsis moves the food to the stomach. In the Stomach Produces gastric juices to aid digestion. Gastric juices made of hydrochloric acid, digestive juices and mucus. Chyme –food and gastric juices combined. Stomach can hold about 1 quart of food. Food stays in stomach 2 to 3 hours.

Process of Digestion In the Small Intestine 95% of digestion occurs here. Has 3 sections: duodenum, jejunum, ileum. Is about 20 feet long and 1 inch in diameter. Takes about 5-14 hours for food to move from the mouth through small intestine. Pancreas, a gland behind the stomach aids the small intestine in creating the right environment. Liver is involved in the chemical digestion in the small intestine with use of bile.

Process of Digestion Large Intestine Food moves from small intestine to the large intestine (colon). Measure 5-6 feet when stretched. Main job is to reabsorb water, very little digestion. Chyme stays in large intestine 1-3 days before elimination. Solid waste called feces, leave the large intestine through the rectum and the body through the anus.

Absorption of Nutrients Defined as the passage of nutrients from the digestive tract into the circulatory or lymphatic system. Most nutrients pass through the walls of small intestine Alcohol and few other drugs can be absorbed in stomach. Alcohol can also be dissolved in the mouth. Inside surface of small intestine. Pleated with thousands of folds. Folds are covered with villi. Every cell of every villus is covered with microvilli Water-soluble nutrients –dissolve in water. Include amino acids, monosaccharides, minerals, most vitamins and water. Capillaries in villi carry these into bloodstream and to the liver. Fat-soluble nutrients – dissolve in fat. Vitamins A,D,E,K and fatty acids, glycerol, and monoglycerides. Absorbed into the lymphatic system and into the bloodstream. Absorption in Large Intestine Absorbs small amounts of water and some minerals.

Metabolism Defined as all the chemical changes that occur as cells produce energy and materials need to sustain life. During metabolism Cells make some compounds Some are used for energy. Some stored for later use. Through metabolism Cells broken down for energy ATP found in muscles for instant energy. Waste from cell metabolism Leave body through kidneys, lungs and skin. Urine, thus we need 6-8 glasses of water daily. Carbon dioxide through lungs. Perspiration through your skin.

Factors Affecting Digestion and Absorption Eating Habits Choose a nutritious diet that includes a wide range of foods. Fiber – indigestible material. Found in fresh fruits and vegetables and whole grain products. Strengthens the intestinal muscles. Take time to enjoy your food, no rushing to eat. Don’t eat too much too fast, watch your portions. Don’t stuff yourself. Watch the make up of your food choices. High fat foods longer to digest. Foods high in carbs leave stomach faster. Be aware of the wholesomeness of your food. Spoiled and contaminated foods can cause intestinal problems. Emotions Reduce stress while eating Enjoyable environment helps. Chew food slowly and thoroughly. Food Allergies Food allergy is a reaction of the immune system to certain proteins found in food. Symptoms – vomiting, stomach pain, intestinal distress, skin rashes, swelling, and breathing problems. Common food allergies to nuts, eggs, milk and soybeans and wheat. Food sensitivities - lactose intolerant one example. Physical Activity Aids in digestion and metabolism Stimulates a healthy appetite and strengthens muscles of the internal organs.

Digestive Disorders Diarrhea Constipation Indigestion Heartburn Ulcer Causes food to move through digestive system too quickly for nutrients to be fully absorbed. Leads to a loss of body fluids Constipation Feces become hard in large intestine, making bowel movements painful. Caused by erratic eating habits, low fiber intake, lack of physical activity, drinking too little water. Indigestion Caused by stress, eating too much or too fast, or eating particular foods. Symptoms are gas, stomach cramps and nausea. Heartburn Caused by stomach acid flowing back into the esophagus. Known as reflux GERD Ulcer Open sore in the lining of the stomach or small intestine, caused by a bacterium. May be hereditary connection, stress, or excessive alcohol or aspirin use. Gallstones Small crystals that form from bile in the gallbladder. When these block the duct connecting the gallbladder to small intestine cause for great pain. May slow fat digestion and pools of fluid in the liver. Diverticulosis Abnormal pouches forming in the intestinal wall and become inflamed. Caused by diet too low in fiber, or diet too high in fat or an inactive lifestyle.