Presentation on theme: "2 Nutritional Needs. 2 Nutritional Needs Objectives Name the key nutrients, describe their functions, and list important sources of each. Analyze the."— Presentation transcript:
3ObjectivesName the key nutrients, describe their functions, and list important sources of each.Analyze the effects of various nutrient deficiencies and excesses.Explain the processes of digestion, absorption, and metabolism.
4The NutrientsFood provides nutrients, which are necessary for good healthNutrition examines how the body uses nutrientsIf you do not eat the foods your body needs, you may suffer from malnutritioncontinued
5The Nutrients Nonessential nutrients are substances the body can make Essential nutrients are substances the body cannot make and must be supplied by the foods you eatcontinued
7The NutrientsFailure to get enough of the needed nutrients may result in a deficiency diseaseConsuming too much of some nutrients can result in toxicity
8Dietary SupplementsDoctors may recommend dietary supplements to help make up for nutrient shortages in the dietSome dietary supplements provide nonnutrient substances, such as herbs and some antioxidantscontinued
11Functions of Carbohydrates Carbohydrates are sources of energy for the body and brainFiber does not provide energy, but can helpreduce the risk of heart diseasespeed food through the bodydilute carcinogens (cancer-causing agents)reduce the risk of cancer
13Carbohydrate Deficiencies and Excesses A carbohydrate deficiency can cause the body to use protein as an energy sourceThis can interfere with the normal growth and repair of body tissues and potentially create a chemical imbalanceConsuming too many simple carbohydrates can result in nutrient shortages and excess calories
14Fats Fats belong to a group of compounds called lipids Lipids, which include both fats and oils, contain fatty acidsBased on the amount of hydrogen atoms found in their molecules, fatty acids are classified as saturated or unsaturated
15Types of FatsSaturated fatty acids have as many hydrogen atoms as they can holdUnsaturated fatty acids have fewer hydrogen atoms than they can holdmonounsaturatedpolyunsaturatedHydrogenation makes unsaturated fatty acids saturated and creates trans fatty acidscontinued
16Types of FatsCholesterol is a fatlike substance that serves important functions in the bodyPart of skin tissueAids in transport of fatty acidsProduces hormones
20Fat Deficiencies and Excesses A diet low in fat may result in a loss of weight and energyDiets high in fat have been linked to heart disease, some cancers, and weight gainNo more than 35 percent of the calories in your daily diet should come from fatNo more than 10 percent of total calories should come from saturated fat
21ProteinsProteins, the third category of essential nutrients, are made of amino acidsEssential amino acidsNonessential amino acidsComplete proteins contain all nine essential amino acidsIncomplete proteins are missing one or more of the essential amino acids
22Functions of Proteins Growth, maintenance, and repair of tissues Formation of enzymes, some hormones, and antibodiesSource of energyRegulation of bodily processes
26Vitamins Each vitamin serves unique functions The body cannot produce most vitamins in quantities large enough to meet nutritional needsA varied, nutritious diet is best to get the vitamins the body needscontinued
28Fat-Soluble Vitamins Vitamin A aids the eyes with ability to see at nightpromotes bone growthkeeps skin and other tissues healthyfound in liver, egg yolk, and whole milkhas higher values in orange and dark green fruits and vegetablescontinued
30Fat-Soluble Vitamins Vitamin E acts as an antioxidant protects red and white bloods cells, fatty acids, and vitamin Acommon in many food items, including fats and oils, whole-grain products, liver, eggs, whole milk dairy foods, and leafy green vegetablescontinued
32Water-Soluble Vitamins Vitamin C (ascorbic acid)helps form and maintain collagen, which holds body cells togetherfirms the walls of blood vesselshelps heal wounds and broken boneshelps create hemoglobin and fight infectionsfunctions as a dietary antioxidantfound in many fresh fruits and vegetablescontinued
33Water-Soluble Vitamins B-complex vitamins work together in the bodythiaminriboflavinniacinvitamin B6folatevitamin B12biotincontinued
35Water-Soluble Vitamins Riboflavin (B2)helps break down carbohydrateshelps cells use oxygenkeeps skin, tongue, and lips healthyfound in milk, eggs, oysters, leafy green vegetables, and whole-grain enriched cereal productscontinued
36Water-Soluble Vitamins Niacinhelps keep the nervous system, mouth, skin, tongue, and digestive tract healthyhelps cells use nutrientsfound in meats, poultry, and peanutstoo much niacin can cause nausea, vomiting, and red flushingcontinued
37Water-Soluble Vitamins Vitamin B6helps nerve tissues function normallyaids with the regeneration of red blood cellshelps break down proteins, carbohydrates, and fatsfound in vegetables, muscle meats, and whole-grain cerealscontinued
39Water-Soluble Vitamins Vitamin B12promotes normal growthaids in normal functioning of cells in bone marrow, nervous system, and intestinesfound in animal protein foods and cerealsPantothenic Acidhelps the body use energy nutrients and make cholesterolpromotes growthfound in plant and animal tissues, yeast, and milkcontinued
41Vitamin Deficiencies and Excesses Vitamin deficiencies can result in such conditions and diseases as night blindness, rickets, scurvy, beriberi, pellagra, and anemia
42Did You Know?The term vitamin was originally vitamine, a combination of the words vita and amine. Vita is Latin for life. Amine referred to amino acids, which scientists initially thought were part of the make up of vitamins. The final e was later dropped when scientists learned that vitamins did not contain amino acids.
43MineralsThe body needs at least 21 minerals for good health, which can be obtained from a variety of foodsMacrominerals are needed in large quantities per dayTrace elements, or microminerals, are needed in smaller quantities per day
46Macrominerals Magnesium helps regulate the body’s temperature keeps the nervous system working properlyfound in whole grains and grain products, nuts, beans, meats, and dark green leafy vegetablescontinued
47Macrominerals Sodium, chloride, and potassium work as a team to control osmosishelp the nervous system and muscles functionhelp cells absorb nutrientscommon in the food supply and U.S. dietsources include table salt, many types of seafood, many vegetables, and fruits
48Trace Elements Iron Zinc helps form hemoglobin, which carries oxygen throughout the bodyfound in animal sources and leafy green vegetablesZincaids the immune systempromotes normal growth and developmentfound in meats and whole grainscontinued
55Water RequirementsMost people should consume about 1 ounce of fluid for every 2 pounds of body weightClimate, health, and eating habits affect water needsThirst is the first symptom of water lossToo much water can result in water intoxication, a rare condition
58The Digestion Process Mechanical phase begins in the mouth when teeth chew food and break it down into smaller piecesinitiates contractions in the digestive tract, known as peristalsiscontinued
59The Digestion Process Chemical phase begins in the mouth when food mixes with salivagastric juices break down food in the stomachthe semiliquid leaves the stomach and enters the small intestine, where intestinal juices, pancreatic juices, and bile act on the foodcontinued
60The Digestion Processdigestive enzymes help break foods down into simple substances the body can absorb and useonce digestion is complete, absorption can take placesome substances then travel into the large intestine, which acts as a reservoirthe body excretes these materials in the feces
62MetabolismMetabolism takes place in the cells after the body absorbs nutrientsNutrients follow a distinct metabolic pathCarbohydrates become glucose for energy or glycogen for storagecontinued
63Metabolism During fat metabolism, fats become fuel During protein metabolism, amino acids are used for cell maintenance and growth or as energy
64Review What are the six essential nutrients? carbohydrates fats proteinsvitaminsmineralswater
65Review 2. What is one function of each of the key nutrients? Answers will vary.3. What are two important sources of each of the key nutrients?
66Review4. How can deficiencies and excesses of various nutrients affect the body?nutrient deficiencies can result in deficiency diseases, protein-energy malnutrition, night blindness, rickets, scurvy, beriberi, pellagra, anemia, osteoporosis, hypertension, and goiter; nutrient excesses can result in toxicity
67Review5. What occurs in the body during the processes of digestion, absorption, and metabolism?digestion breaks food down into simple materials the body can use; absorption involves taking in nutrients and making them part of the body; metabolism involves chemical processes that take place in the cells after the body absorbs nutrients
68Glossaryabsorption. The process of taking nutrients into the body and making them part of the body.amino acid. A chemical compound that serves as a building block of proteins.anemia. A condition resulting from deficiencies of various nutrients, which is characterized by a reduced number of red blood cells in the bloodstream.
69Glossaryantioxidant. A substance that prevents or slows down damage caused by chemical reactions involving oxygen.beriberi. A disease of the nervous system resulting from a thiamin deficiency, which is characterized by numbness in the ankles and legs followed by severe cramping and paralysis and potentially fatal heart disturbances.
70Glossarycarbohydrate. One of the six basic types of nutrients that is the body’s chief source of energy.cholesterol. A fatlike substance that occurs naturally in the body and is found in every cell. It occurs only in foods of animal origin.
71Glossarydeficiency disease. An illness caused by the lack of a sufficient amount of a nutrient.dietary supplement. A purified nutrient or nonnutrient substance that is manufactured or extracted from natural sources.
72Glossarydigestion. The bodily process of breaking food down into simpler compounds the body can use.fat. One of the six basic types of nutrients that is an important energy source belonging to a larger group of compounds called lipids.
73Glossaryfat-soluble vitamin. A vitamin that dissolves in fats and can be stored in the fatty tissues of the body.fatty acid. A chemical chain containing carbon, hydrogen, and oxygen that is the basic component of all lipids.fiber. A form of complex carbohydrate from plants that humans cannot digest.
74Glossaryfortified food. A food to which nutrients are added in amounts greater than what would naturally occur in the food.glucose. The form of sugar carried in the bloodstream for energy use throughout the body.goiter. A visible enlargement of the thyroid gland resulting from an iodine deficiency.
75Glossaryhydrogenation. A process by which hydrogen atoms are chemically added to unsaturated fatty acids in liquid oils to turn the oils into more highly saturated solid fats.hypertension. High blood pressure.macromineral. A mineral needed in the diet in amounts of 100 or more milligrams each day.
76Glossarymalnutrition. A lack of the right proportions of nutrients over an extended period, which can be caused by an inadequate diet or the body’s inability to use the nutrients from foods.metabolism. The chemical processes that take place in the cells after the body absorbs nutrients.
77Glossarymineral. One of the six basic types of nutrients that is an inorganic substance and becomes part of the bones, soft tissues, and body fluids.night blindness. A condition resulting from a vitamin A deficiency, which is characterized by a reduced ability to see in dim light.
78Glossarynutrient. A chemical substance from food the body needs to live.nutrition. The study of how the body uses the nutrients in foods that are eaten.osteoporosis. A condition resulting from a calcium deficiency, which is characterized by porous, brittle bones.
79Glossarypellagra. A disease resulting from a niacin deficiency that is characterized by skin lesions and digestive problems. Mental disorders and death may follow if left untreated.peristalsis. Waves of muscle contractions that push food through the digestive tract.
80Glossaryprotein. One of the six basic types of nutrients, made up of amino acids, that is required for growth, repair, and maintenance of every body cell.protein-energy malnutrition (PEM). A condition that may result from a diet that does not contain enough protein and calories.
81Glossaryrickets. A disease resulting from a vitamin D deficiency, which is characterized by crooked legs and misshapen breast bones in children, and bone abnormalities in adults.saliva. A mucus- and enzyme-containing liquid secreted by the mouth that makes food easier to swallow and begins to break down starches.
82Glossaryscurvy. A disease resulting from a vitamin C deficiency, which is characterized by bleeding gums, loss of teeth, and internal bleeding.toxicity. Poisoning.trace element. A mineral needed in the diet in amounts less than 100 milligrams per day.
83Glossarytrans fatty acid. A fatty acid with an odd molecular shape that is created in hydrogenated oils and found naturally in dairy products, beef, and lamb.vitamin. One of the six basic types of nutrients that is a complex organic substance needed by the body in small amounts for normal growth, maintenance, and reproduction.
84Glossarywater-soluble vitamin. A vitamin that dissolves in water and is not stored in the body to any great extent.