© Cengage Learning 2016 Personal Nutrition, 9e Boyle | Long The Carbohydrates: Sugar, Starch, and Fiber 4

© Cengage Learning Describe how carbohydrates are used in the body. 4.2Identify major food sources of the monosaccharides, disaccharides, and polysaccharides common in nutrition. 4.3Describe the health benefits associated with complex carbohydrates, including the two major types of dietary fibers. Chapter Objectives

© Cengage Learning List the dietary recommendations for total carbohydrate, dietary fiber, and added sugars in the diet. 4.5Summarize carbohydrate digestion and explain how the body maintains a normal blood glucose level. 4.6Differentiate between type 1 and type 2 diabetes, including risk factors for each. Chapter Objectives

© Cengage Learning Identify strategies for reducing added sugars in the diet. 4.8List examples of alternatives sweeteners approved for use in the diet. Chapter Objectives

© Cengage Learning 2016 Roles of carbohydrates –Primary role: provide the body with energy (calories) Four calories per gram Preferred fuel for the brain and nerves –Provide an energy reserve Glycogen –Serve as raw materials for other compounds –Supply the body with fiber 4.1 Carbohydrate Basics

© Cengage Learning 2016 Monosaccharides: single sugars –Glucose: dextrose or blood sugar The body can convert all carbohydrates other than fiber into glucose Plants make glucose from CO 2 and H 2 O through process of photosynthesis –Fructose: fruit sugar or levulose –Galactose is part of lactose 4.2 The Simple Carbohydrates: Monosaccharides and Disaccharides

© Cengage Learning 2016 Disaccharides: double sugars –Sucrose: table sugar Glucose + fructose –Lactose: milk sugar Glucose + galactose –Maltose: malt sugar Glucose + glucose 4.2 The Simple Carbohydrates: Monosaccharides and Disaccharides

© Cengage Learning 2016 Starch: a plant polysaccharide composed of hundreds of glucose molecules –Sources: grains, peas, beans, legumes, root vegetables, and tubers –Staple grains: provide most of the people’s food energy Asian nations: rice Canada, U.S. and Europe: wheat 4.3 The Complex Carbohydrates: Starch and Fibers

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The bread box: refined, enriched, and whole-grain breads –Refined: grains that have been milled to remove the husk, bran, and germ from the grain—leaving only the endosperm –Enriched: process by which the B vitamins thiamin, riboflavin, niacin, folic acid, and the mineral iron are added to refined grains and grain products at levels specified by law 4.3 The Complex Carbohydrates: Starch and Fibers

© Cengage Learning 2016 The bread box: refined, enriched, and whole-grain breads –Fortified: term for foods to which nutrients have been added (e.g., milk with vitamin D) Helps prevent deficiencies Reduces the risk of chronic diseases –Whole grain: grain that is milled in its entirety (all but the husk), not refined 4.3 The Complex Carbohydrates: Starch and Fibers

© Cengage Learning 2016 The bread box: refined, enriched, and whole-grain breads –Wheat kernel Made into flour and subsequently, bread Main parts: germ, endosperm, bran, and husk (chaff) –Whole-grain products are preferable to enriched products 4.3 The Complex Carbohydrates: Starch and Fibers

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Dietary fibers –Plant fibers forming the supporting structures Leaves, stems, and seeds –Polysaccharides with bonds between glucose units that are not broken in the human digestive system –Forms of fiber Insoluble fiber Soluble fiber 4.3 The Complex Carbohydrates: Starch and Fibers

© Cengage Learning 2016 The health effects of fiber 4.3 The Complex Carbohydrates: Starch and Fibers

© Cengage Learning 2016 The health effects of fiber 4.3 The Complex Carbohydrates: Starch and Fibers

© Cengage Learning 2016 Recent nutrition guidelines –Favor a whole-food, plant-based diet Complex carbohydrates in the diet –Dietary Guidelines for Americans recommendations Increase vegetable and fruit intake Eat a variety of vegetables Consume at least half of all grains as whole grains –MyPlate advocates diets with proportionally more whole grains, vegetables, and fruits 4.4 Guidelines for Choosing Carbohydrates

© Cengage Learning 2016 Fiber in the diet –What is the correct amount to consume? Too much fiber can cause dehydration and intestinal discomfort Too much bulk can cause deficiencies in both nutrients and energy Adequate fiber is supplied with a diet high in a variety of fruits, vegetables, legumes, and whole grains 4.4 Guidelines for Choosing Carbohydrates

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A nutritious diet should emphasize whole grains Whole grains have beneficial factors –Vitamins, minerals, fiber, and other protective substances (e.g., phytonutrients) Benefits of whole-grain-rich diets –Improved insulin sensitivity –Lower risk of metabolic syndrome Eat Well Be Well: Whole Grains for Health

© Cengage Learning 2016 How can you incorporate whole grains into your diet to achieve health benefits? –Count to three: consume three or more servings of whole-grain products per day with remainder of servings from enriched or whole- grain products –Keep it varied: choose a variety of whole- grain foods –Check the label: look for whole-grain listed first on a product’s ingredient list Eat Well Be Well: Whole Grains for Health

© Cengage Learning 2016 Added sugars: use discretion –Dietary Guidelines for Americans advises Reduce the intake of calories from added sugars –World Health Organization recommends Added sugar intake limited to 10 percent of calories –Maximum intake as set by the Dietary Reference Intakes (DRI) committee 25 percent of total calories or less 4.4 Guidelines for Choosing Carbohydrates

© Cengage Learning 2016 Added sugars: use discretion –Highest intakes are in men ages 19 to 30 Up to 55 teaspoons of sugar a day –What are the major sources of added sugars in American diets? Regular soft drinks Sugars and candy; cakes, cookies, and pies Fruit drinks Dairy products (e.g., ice cream) Sweetened grains (e.g., waffles) 4.4 Guidelines for Choosing Carbohydrates

© Cengage Learning 2016 Glucose is the basic carbohydrate unit that each cell of the body uses for energy Digestive system breaks down –Disaccharides and starch into monosaccharides absorbed into the blood Saliva begins the breakdown of starch Enzymes in the stomach and intestines continue digestive action Glucose is absorbed and circulates to the cells 4.5 How the Body Handles Carbohydrates

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How is glucose used by cells? –Stored: glycogen is stored in muscle and in the liver –Used for current energy needs –Converted to fat 4.5 How the Body Handles Carbohydrates

© Cengage Learning 2016 Maintaining the blood glucose level –When blood glucose levels rise Pancreas releases insulin Cells respond by making glycogen or fat –When blood glucose is too low Pancreas releases glucagon Glucose is taken from storage to provide energy 4.5 How the Body Handles Carbohydrates

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Maintaining the blood glucose level –In what ways does a balanced meal help maintain the correct blood glucose level? Carbohydrates provide a quick source of glucose Protein stimulates glucagon secretion and prevents insulin from storing glucose too quickly Soluble fibers and fat slow down digestion supplying glucose at a steady rate 4.5 How the Body Handles Carbohydrates

© Cengage Learning 2016 Hypoglycemia: an abnormally low blood glucose concentration, below 60 to 70 mg/100 mL –What are symptoms of glucose deprivation to the brain? Irritability Weakness and dizziness Muscles become weak, shaky, and trembling Heart races 4.6 Hypoglycemia and Diabetes

© Cengage Learning Hypoglycemia and Diabetes

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Glycemic effect –The effect of food on a person’s blood glucose and insulin response How fast and how high the blood glucose rises and how quickly the body responds by bringing it back to normal Glycemic index (GI) –Ranks foods on the basis of the extent to which the foods raise the blood glucose level as compared with pure glucose Nutrition Action: Carbohydrates—Friend or Foe?

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Sugar is linked directly to tooth decay Consume concentrated refined sugars in moderation –Do not displace needed nutrients Keeping sweetness in the diet –Use less of all sugars –Limit intakes of beverages and food with added sugars –Eat fresh fruits to satisfy cravings for sweets 4.7 Sugar and Health

© Cengage Learning 2016 Keeping sweetness in the diet –Check ingredients lists for added sugars –Monitor how frequently and how much sugar you eat –Choose healthy alternatives for sweet desserts, e.g., whole-grain crackers and fruit –Drink fruit juices or water in place of beverages with added sugars –Buy unsweetened cereals to control the amount of added sugars 4.7 Sugar and Health

© Cengage Learning 2016 Keeping sweetness in the diet –Experiment with reducing the amount of sugar in recipes –Add sweet spices to substitute for some sugar in recipes 4.7 Sugar and Health

© Cengage Learning 2016 Keeping a healthy smile –American Dental Association (ADA) advice Eat a balanced diet Keep snacking to a minimum, if possible Eat sweets with meals rather than between them Brush and floss thoroughly each day Use an ADA-accepted fluoride toothpaste Visit a dentist regularly Do not allow an infant to sleep with a bottle with sweetened liquids, fruit juices, milk, or formula 4.7 Sugar and Health

© Cengage Learning 2016 Nonnutritive sweeteners –Synthetic or natural ingredients added to foods and beverages to provide sweetness with negligible, if any, calories Saccharin-sweetened foods and beverages –Saccharin warning label is no longer required Aspartame is considered safe for use –Except for people with phenylketonuria (PKU) 4.8 Spotlight: Sweet Talk—Alternatives to Sugar

© Cengage Learning 2016 Splenda is available in a form that is highly interchangeable with regular sugar Adding nonnutritive sweeteners to the diet does not guarantee weight loss Any carbohydrate-containing food, even those with artificial sweeteners, promote tooth decay Diabetics should discuss options of sugar substitutes with a dietician and physician 4.8 Spotlight: Sweet Talk—Alternatives to Sugar

© Cengage Learning 2016 Sugar alcohols, e.g., xylitol and sorbitol –Are associated with less cavity formation –Contribute 1.5 to 3 calories per gram Stevia –Stevioside is its main ingredient 200 to 300 times as sweet as sugar Calorie-free –FDA-approved as a sweetener and food additive in Spotlight: Sweet Talk—Alternatives to Sugar