2 Lecture ObjectivesList the six essential nutrients and describe their functions in the body.List the acceptable macronutrient distribution ranges.Explain the difference between the following:Complete and incomplete proteinsSaturated, unsaturated, and trans fatSimple and complex carbohydratesSoluble and insoluble fiberExplain the role of fiber and antioxidants in the body.
3 Nutritional Requirements: Components of a Healthy Diet Essential nutrientsProteinsFatsCarbohydratesVitaminsMineralsWaterEssential nutrients = substances the body must get from food because it cannot manufacture them at all or fast enough to meet its needs
4 Acceptable Macronutrient Distribution Ranges CHOCHO (45-65%)FATFAT (20-35%) - 10% saturatedPROPRO (10-35% or less)Three classes of essential nutrients supply energyKilocalorie = a measure of energy content in food; the amount of heat it takes to raise the temperature of 1 liter of water 1°C; commonly referred to as “calorie”
5 Proteins: The Basis of Body Structure Protein is a compound9 / 20 common amino acids in foods are essentialProtein = a compound made of amino acids that contains carbon, hydrogen, oxygen, and nitrogenProteins form key parts of the body’s main structural components—muscles and bones—and of blood, enzymes, cell membranes, and some hormones
6 Complete and Incomplete Proteins Complete protein sourcesMeat, fish, poultry, eggs, milk, cheese, and soyIncomplete protein sourcePlants, including legumes, grains, and nutsComplete protein sources = foods that supply all the essential amino acids in adequate amountsIncomplete protein sources = foods that supply most but not all essential amino acids
7 Recommended Protein Intake 0.8 gram per kilogram (0.36 gram per pound) of body weight dailyAcceptable Macronutrient Distribution Range =10–35% of total daily calories as protein
8 Protein Sources 3 ounces lean meat, poultry, or fish 1/2 cup tofu 20–25 grams of protein1 cup legumes15–20 grams of protein1 cup milk or yogurt or 1-1/2 ounces cheese8–12 grams of proteinCereals, grains, nuts, vegetables2–4 grams of protein per serving
9 Fats: Essential in Small Amounts What role do fats play in my diet?Essential fats are key regulatorsFats supply energy, insulate the body, support and cushion organs, absorb fat-soluble vitamins, add flavor and texture to foodsEssential fats (linoleic acid and alpha-linolenic acid) are key regulators of body process such as the maintenance of blood pressure and the progress of a healthy pregnancy
10 Types and Sources of Fats Saturated fatMonounsaturated fatPolyunsaturated fatTrans FatSaturated fat = a fat with no carbon-carbon double bonds; usually solid at room temperatureMonounsaturated fat = a fat with one carbon-carbon double bond; usually liquid at room temperaturePolyunsaturated fat = a fat with two or more carbon-carbon double bonds; usually liquid at room temperatureTwo key forms of polyunsaturated fats:Omega-3 fatty acids are produced when the endmost double bond of a polyunsaturated fat occurs three carbons from the end of the fatty acid chainFound primarily in fishOmega-6 fatty acids are produced when the endmost double bond of a polyunsaturated fat occurs six carbons from the end of the fatty acid chainFound primarily in certain vegetable oils, especially corn, soybean, and cottonseed oilTrans Fatty Acids: The process of hydrogenation, in which hydrogens are added to unsaturated fats, produces a mixture of saturated fatty acids and standard and trans forms of unsaturated fatty acidsTrans fatty acids have an atypical shape that affects their chemical activity______________________________Fats affect blood cholesterol levelsLow-density lipoprotein (LDL) = “bad” cholesterolHigh-density lipoprotein (HDL) = “good” cholesterolSaturated and trans fats raise levels of LDL; trans fats also lower levels of HDLUnsaturated fats lower levels of LDL_________________________Fats also affect triglyceride levels, inflammation, heart rhythm, blood pressure, and cancer riskBest choices = monounsaturated fats and polyunsaturated omega-3 fatsLimit intake of saturated and trans fats
11 Fats and Health Fats affect blood cholesterol levels “Bad” cholesterol vs. “good” cholesterolSaturated and trans fats vs. unsaturated fatsFats also affect triglyceride levels, inflammation, heart rhythm, blood pressure, and cancer riskBest choices = monounsaturated fats and polyunsaturated omega-3 fatsLimit intake of saturated and trans fatsLow-density lipoprotein (LDL) = “bad” cholesterolHigh-density lipoprotein (HDL) = “good” cholesterolSaturated and trans fats raise levels of LDL; trans fats also lower levels of HDLUnsaturated fats lower levels of LDL
12 Total Fat Content of Foods Talk about importance of food choices. Some are everyday foods, some are sometimes foods. There is no “bad” food, all foods in moderation is key.
13 Recommended Fat Intake Adequate daily intake of fat:Women = 13 gramsMen = 18 gramsAcceptable Macronutrient Distribution Range =20–35% of total daily calories as fat
14 Carbohydrates: An Ideal Source of Energy Primary FunctionSome cells use only carbohydrates for fuelBody’s preferred fuel sourceBroken down and stored during digestionThe primary function of dietary carbohydrate is to supply energy to body cells.Some cells, such as those in the brain, nervous system, and blood, use only carbohydrates for fuelDuring high-intensity exercise, muscles get most of their energy from carbohydratesDuring digestion, carbohydrates are broken into single sugar molecules such as glucose for absorption; the liver and muscles take up glucose and store it in the form of glycogen
15 Simple and Complex Carbohydrates Simple carbohydrates contain one or two sugar units in each moleculeComplex carbohydrates consist of chains of many sugar moleculesSimple carbohydrates contain one or two sugar units in each moleculeFound naturally in fruits and milk and added to many other foodsInclude sucrose, fructose, maltose, and lactoseComplex carbohydrates consist of chains of many sugar moleculesFound in plants, especially grains, legumes, and tubersInclude starches and most types of dietary fiber
16 Whole GrainsRefined carbohydrates usually retain all the calories of a whole grain but lose many of the nutrientsBefore they are processed, all grains are whole grains consisting of an inner layer of germ, a middle layer called the endosperm, and an outer layer of branDuring processing, the germ and bran are often removed, leaving just the starchy endosperm_____________________________REFINED CHO VS WHOLE GRAINWhole grains are higher than refined carbohydrates in fiber, vitamins, minerals, and other beneficial compoundsWhole grains take longer to digestChoose foods that have a whole grain as the first item on the ingredient list on the food label
17 Recommended Carbohydrate Intake Adequate daily intake of carbohydrate = 130 gramsAcceptable Macronutrient Distribution Range = 45–65% of total daily calories as carbohydrateLimit intake of added sugarsIncrease consumption of unrefined grains, fruits, vegetables, and legumes
18 Vitamins: Organic Micronutrients Four vitamins are fat-soluble(A, D, E, and K)Nine vitamins are water-soluble(C and the eight B-complex vitamins: thiamin, riboflavin, niacin, vitamin B-6, folate, vitamin B-12, biotin, and pantothenic acid)Do NOT provide kcals!Vitamins = organic (carbon-containing) substances needed in small amounts to help promote and regulate chemical reactions and processes in body cells.Vitamins are abundant in fruits, vegetables, and grains; they are also added to some processed foodsIf you consume too much or too little of a particular vitamin, characteristic symptoms of excess or deficiency can developVitamins commonly lacking in the American diet:Vitamin AVitamin CVitamin B-6Vitamin E
19 Minerals: Inorganic Micronutrients There are about 17 essential minerals:Major minerals (those that the body needs in amounts exceeding 100 mg per day):Calcium, phosphorus, magnesium, sodium, potassium, and chlorideEssential trace minerals:Copper, fluoride, iodide, iron, selenium, and zincMinerals = inorganic (non-carbon-containing) compounds needed in small amounts for regulation, growth, and maintenance of body tissues and functionsIf you consume too much or too little of a particular mineral, characteristic symptoms of excess or deficiency can developMinerals commonly lacking in the American diet:Iron = low intake can cause anemiaCalcium = low intake linked to osteoporosisPotassium = low intake linked to elevated blood pressure and bone mineral loss
20 Water: A Vital Component Human body is composed of about 60% water; you can live only a few days without waterFoods and fluids you consume provide 80–90% of your daily water intakeAdequate intake?Adequate intake to maintain hydration:Women need to drink about 9 cups of fluid per dayMen need to drink about 13 cups of fluid per dayDrink in response to thirst; consume additional fluids for heavy exercise
21 Other Substances in Food: Fiber Dietary fiber=non-digestibleFunctional fiber=non-digestibleTotal fiber=dietary fiber+functional fiberDietary fiber = nondigestible carbohydrates and lignin that are present naturally in plantsFunctional fiber = nondigestible carbohydrates isolated from natural sources or synthesized in a lab and added to a food or supplementTotal fiber = dietary fiber + functional fiber
22 Types of Fiber Soluble (viscous) fiber Insoluble fiber Sources of FiberRecommended intake?Soluble (viscous) fiber = fiber that dissolves in water or is broken down by bacteria in the large intestineSlows the body’s absorption of glucoseBinds cholesterol-containing compoundsInsoluble fiber = fiber that doesn’t dissolve in waterMakes feces bulkier and softerHelps prevent constipation, hemorrhoids, and diverticulitisSources of Fiber:All plant foods contain fiber, but processing can remove itGood sources of fiber:Fruits (especially whole, unpeeled fruits)VegetablesLegumesOats (especially oat bran)Whole grains and wheat branPsyllium (found in some cereals and laxatives)_______________________RECOMMENDED INTAKEWomen = 25 grams per dayMen = 38 grams per dayAmericans currently consume about half this amount
23 Other Substances in Food: Antioxidants Antioxidant = a substance that protectsMany fruits and vegetables are rich in antioxidants such as vitamin C, vitamin E, selenium, and carotenoidsAntioxidant = a substance that protects against the breakdown of body constituents by free radicals; actions include binding oxygen, donating electrons to free radicals, and repairing damage to moleculesFree radical = a chemically unstable, electron-seeking compound that can damage cell membranes and mutate genes in its search for electrons
24 Lecture SummaryList the six essential nutrients and describe their functions in the body.List the acceptable macronutrient distribution ranges.Explain the difference between the following:Complete and incomplete proteinsSaturated, unsaturated, and trans fatSimple and complex carbohydratesSoluble and insoluble fiberExplain the role of fiber and antioxidants in the body.