The Carbohydrates: Sugar, Starch, and Fiber Chapter 4 FCS 342

Outline Describe how carbohydrates are used in the body. Identify major food sources of the monosaccharides, disaccharides, and polysaccharides common in nutrition. Describe the health benefits associated with complex carbohydrates, including the two major types of dietary fibers. List the dietary recommendations for total carbohydrate, dietary fiber, and added sugars in the diet. Summarize carbohydrate digestion and explain how the body maintains a normal blood glucose level. Differentiate between type 1 and type 2 diabetes, including risk factors for each. Identify strategies for reducing added sugars in the diet. List examples of alternatives sweeteners approved for use in the diet.

Ask Yourself… 1. Fruit sugar (fructose) is less fattening than table sugar (sucrose). 2. Foods high in complex carbohydrate (starch and fiber) are good choices when you are trying to lose weight. 3. People with diabetes should never eat sugar. 4. The primary role of dietary fiber is to provide energy. 5. The brain depends on the sugar, glucose, to fuel its activities. 6. Honey and refined sugar are the same as far as the body is concerned. 7. Of all the components of foods that increase one’s risk of diseases, sugars are probably the biggest troublemakers. 8. Breads that are brown in color have more fiber than white bread. 9. Some foods labeled sugar-free actually contain calorie-bearing sugars. 10. Artificial sweeteners are safe to consume in moderation.

Carbohydrate Basics What are carbohydrates?  ______________ of the ______________ macronutrients  Diverse group of compounds produced primarily by plants

Carbohydrate Basics Roles of carbohydrates  Primary role: provide the body with ______________ (kcals)  1 gram carbs = 4 kcals  Preferred fuel for the brain  Provide an energy reserve  ______________  Serve as raw materials for other compounds  Supply the body with ______________

Classifying Carbohydrates Simple Carbohydrates Monosaccharides  Glucose  Fructose  Galactose Disaccharides  Sucrose  Lactose  Maltose Complex Carbohydrates Oligosaccharides Polysaccharides  Starch  Dietary Fiber

The Simple Carbohydrates Monosaccharides  ______________ sugars Types of monosaccharides:  Glucose  Fructose  Galactose

The Simple Carbohydrates Description of monosaccharides :  ______________ : blood sugar or dextrose  The body can convert all carbohydrates other than fiber into glucose  Most abundant monosaccharide in the body  Provides a source of energy (ATP) to cells  Plants make glucose from CO 2 and H 2 O through process of photosynthesis  ______________ : fruit sugar or levulose  Naturally occurring; found in honey, fruits, and veggies  Liver will change fructose to glucose  ______________ : a part of lactose  Few foods contain galactose in its free state  Converted to glucose and used as energy

The Simple Carbohydrates Disaccharides : double sugars; two monosaccharides bonded together  ______________ : table sugar  Glucose + fructose  ______________ : milk sugar  Glucose + galactose  ______________ : malt sugar  Glucose + glucose

The Simple Carbohydrates: Lactose Intolerance ______________ ______________ : inability to digest lactose due to insufficient production of the enzyme lactase  Lactose enters the large intestines undigested  Causes the following symptoms:  Nausea/vomiting  Diarrhea  Excessive gas  Bloating  Abdominal pain High incidence in African, Asian, and Native Americans Good news : most lactose intolerant individuals can consume ______________ ______________ of dairy  Easily tolerated: aged cheeses, yogurt, and kefir  Lactose-reduced dairy and milk substitutes available  OTC lactase enzymes available

Lactose Intolerance vs. Milk Allergy

The Complex Carbohydrates Oligosaccharides Contain 3 – 10 monosaccharides Fructo-oligosaccharides  Sources include wheat, leeks, onions, garlic, and artichokes Galacto-oligosaccharides  Sources include legumes Humans lack enzymes to digest oligosaccharides  Ingestion leads to bloating, cramps, and gas Polysaccharides Contain > 10 monosaccharides Most are made up of hundreds of monosaccharides bonded together Types:  Starch  Glycogen  Dietary fiber

The Complex Carbohydrates: 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  U.S., Canada, and Europe: wheat

The Complex Carbohydrates: Starch Refined, enriched, and whole-grain breads  ______________ : grains that have been milled to remove the husk, bran, and germ from the grain—leaving only the endosperm  ______________ : 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  ______________ : term for foods to which nutrients have been added (e.g., milk with vitamin D)  Helps prevent deficiencies  Reduces the risk of chronic diseases  ______________ : grain that is milled in its entirety, not refined  Wheat kernel  Made into flour and subsequently, bread  Main parts: germ, endosperm, bran, and husk (chaff) Whole-grain products are preferable to enriched products

So, which do you believe is the healthiest choice?

The Complex Carbohydrates: Fiber 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  Not digested or absorbed in the human small intestine  Forms of fiber (classified by solubility)  ______________ fiber

The Complex Carbohydrates: Health Effects of Soluble Fiber

The Complex Carbohydrates: Health Effects of Insoluble Fiber

Fiber and Disease Prevention ______________ Fiber  Reduce risk of heart disease by lowering levels of cholesterol in the blood  Fibers can bind bile, which is made from cholesterol, and cause it to be excreted  Lowers total cholesterol levels and triggers liver to use its own cholesterol to make new bile for digestion  Improve diabetes  Slows digestion/absorption rate of glucose

Fiber and Disease Prevention ______________ Fiber  Reduces constipation and hemorrhoids  Hemorrhoids: veins in the rectum swell, bulge out, become weak, bleed  Reduce risk of colon cancer  Improve diverticulosis  Outpocketings of weakened areas of the intestinal wall that can rupture, causing dangerous infections (diverticulitis)  Fecal material becomes stuck inside the diverticula  Caused by hard and/or dry feces, characteristic of a low-fiber diet

Choosing Carbohydrates Recent nutrition guidelines  Favor a whole-food, ______________ ______________ diet  Consume more foods that ______________ the original, farm-grown product Complex carbohydrates in the diet  Dietary Guidelines for Americans recommendations  Increase ______________ and ______________ intake  Eat a ______________ of vegetables  Consume at least _____________of all grains as whole grains  MyPlate advocates diets with proportionally more whole grains, vegetables, and fruits

Choosing Carbohydrates: MyPlate & The Food Label What to look for on the label:  Whole grain ingredients will be listed as:  Brown rice  Buckwheat  Bulgur  Millet  Oatmeal  Popcorn  Quinoa  Rolled oats  Whole grain barley  Whole grain corn  Whole grain sorghum  Whole oats  Whole rye  Whole wheat  Wild rice

Choosing Carbohydrates: MyPlate & The Food Label Misleading information on the label:  __________ guaranteed to be whole:  Multi-grain  Stone ground  100% wheat  Cracked wheat  Seven grain  Bran  ______________ : could be brown because of added molasses or colorings. What to choose:  Stay away from added sugars  Sucrose, honey, malt syrup, molasses, HFCS  ______________ percent daily value (%DV) of fiber  ______________ %DV of sodium

Choosing Carbohydrates Fiber in the diet  What is the correct amount to consume?  Too much ______________ can cause dehydration and intestinal discomfort  Fiber carries water out of the body  Too much ______________ can cause deficiencies in both nutrients and energy  Iron is absorbed early in the digestive process, and fiber speeds movement of foods through digestive process  Adequate fiber is supplied with a diet high in a variety of fruits, vegetables, legumes, and whole grains  Aim to consume 14 grams of fiber for every 1000 kcals consumed

Choosing Carbohydrates

Whole Grains for Health A nutritious diet should emphasize whole grains Whole grains have beneficial factors  Vitamins, minerals, fiber, and other protective substances Benefits of whole-grain-rich diets  Improved insulin sensitivity  Lower risk of preventable chronic diseases

Whole Grains for Health How can you incorporate whole grains into your diet to achieve health benefits?  ____________________________ : consume three or more servings of whole-grain products per day with remainder of servings from enriched or whole-grain products  ____________________________ : choose a variety of whole-grain foods  ____________________________ : look for whole-grain listed first on a product’s ingredient list

Choosing Carbohydrates 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 ______________ of calories  Maximum intake as set by the Dietary Reference Intakes (DRI) committee  ______________ of total calories or less

Choosing Carbohydrates Added sugars: use discretion  Highest intakes are in ____________________________  Up to ________ teaspoons of sugar a day  55 tsp = 220 grams = ______________  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

A refresher… ructor/video_library/boyle_ /video_library/c h04/#

In what ways can you decrease added sugars in your diet?

How the Body Handles Carbohydrates ______________ is the basic carbohydrate unit that each cell of the body uses for ______________ Digestive system breaks down  Disaccharides and starch into monosaccharides absorbed into the blood  ______________ begins the breakdown of starch  Enzymes in the ______________ and intestines continue digestive action  Glucose is absorbed and circulates to the ______________

How the Body Handles Carbohydrates: Digestion & Absorption Goal of carbohydrate ______________ :  Breakdown large, complex molecules into small, absorbable monosaccharides Absorption:  Monosaccharides from digestion are absorbed by small intestine and taken into blood for immediate energy or stored in liver as ______________  Liver regulates amount of glucose in the blood in response to the hormones ______________ and ______________

How the Body Handles Carbohydrates How is glucose used by cells?  Stored: ______________ is stored in muscle and in the liver  Animal polysaccharide for ______________ storage Found in liver and skeletal muscles Released and used for energy when body senses a drop in blood glucose  Fasting  Low carbohydrate diet  Exercise Excess carbohydrate intake leads to increase in size and/or number of ______________

How the Body Handles Carbohydrates Maintaining the blood glucose level  When blood glucose levels rise  Pancreas releases ______________  Cells respond by making ______________ or fat  When blood glucose is too low  Pancreas releases ______________  Glucose is taken from storage to provide energy

How the Body Handles Carbohydrates: The Role of the Pancreas The pancreas plays a major role in regulating blood glucose levels Alpha and Beta cells of the pancreas:  Alpha cells produce the hormone glucagon  Beta cells produce the hormone insulin

How the Body Handles Carbohydrates: The Role of the Pancreas Response to rising blood glucose:  1. ______________ are eaten  2. ______________ levels rise  3. ______________ released from pancreas  4. ______________ binds to receptors  5. Glucose transporters allow ______________ to enter cell

Hypoglycemia Hypoglycemia: an abnormally low blood glucose concentration, below ______________ mg/dL  What are symptoms of glucose deprivation to the brain?  Irritability  Weakness and dizziness  Muscles become weak, shaky, and trembling  Heart races

Hypoglycemia: The Body’s Response Brain and nervous system depend on circulating blood glucose for ______________ ______________ predominates  Provides the signal to the liver to release ______________ (stored glucose)  Raises blood glucose levels …But what if you’ve used all of your glycogen reserves?  The body will switch to a “fasting state”, and use ______________ for energy  Ketones are an alternative source of glucose used during starvation, fasting, low-carb diets, or uncontrolled diabetes  Used when fatty acids are used for energy without sufficient moderation by insulin

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

Diabetes A disorder characterized by insufficiency or relative ineffectiveness of insulin, which renders a person unable to regulate blood glucose levels normally

Diabetes: Prevalence by State

Diabetes Characterized by ______________, or an abnormally high blood glucose level Side effects of hyperglycemia:  Thirst  Frequent urination  Weakness  Lack of concentration  Hunger  Blurred vision

Diabetes Individuals at ______________ risk of developing type 2 diabetes:  Given birth to a baby weighting > 9 lbs  Have a sibling or parent with diabetes  Are overweight or obese  Get little to no exercise during a typical day  > 45 years of age

Nutrition Action: Carbs Glycemic effect  The effect of ______________ 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  Foods with ______________ GI’s thought to be associated with:  Lower risk of developing type 2 diabetes  Better blood glucose control

Sugar and Your Health Sugar is linked directly to ______________ ______________ Consume sugars in ______________  Do not displace needed nutrients How to keep your diet sweet and satisfying without overusing sugars  Use less of all sugars  Limit intakes of beverages and food with added sugars  Eat ______________ ______________ to satisfy cravings for sweets  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  ______________ with reducing the amount of sugar in recipes  Add sweet spices to substitute for some sugar in recipes

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

Baby Bottle Tooth Decay

Alternatives to Sugar Nonnutritive sweeteners  Synthetic or natural ingredients added to foods and beverages to provide sweetness with negligible, if any, calories Saccharin-sweetened foods and beverages ( Sweet-n-Low )  Saccharin warning label is no longer required Aspartame is considered safe for use ( Equal )  Except for people with phenylketonuria (PKU) Splenda Sucralose ( 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

Nonnutritive Sweeteners: ADI FDAs Acceptable Daily Intake (ADI) Saccharin ( Sweet-n-Low ): 15 mg/kg body weight  45 sweetener packets Aspartame ( Equal ): 50 mg/kg body weight  75 sweetener packets Splenda Sucralose ( Splenda ): 5 mg/kg body weight  23 sweetener packets

Alternatives to Sugar Novel Sweetener: Stevia ( Truvia )  Stevioside is its main ingredient  200 to 300 times as sweet as sugar  Calorie-free  FDA-approved as a sweetener and food additive in 2008  ADI: 4 mg/kg body weight or 9 packets/day Sugar alcohols, e.g., xylitol and sorbitol  Are associated with less cavity formation  Contribute 1.5 to 3 calories per gram  Used in processed foods to add sweetness, bulk, and texture

Ask Yourself… 1. Fruit sugar (fructose) is less fattening than table sugar (sucrose). F 2. Foods high in complex carbohydrate (starch and fiber) are good choices when you are trying to lose weight. T 3. People with diabetes should never eat sugar. F 4. The primary role of dietary fiber is to provide energy. F 5. The brain depends on the sugar, glucose, to fuel its activities. T 6. Honey and refined sugar are the same as far as the body is concerned. T 7. Of all the components of foods that increase one’s risk of diseases, sugars are probably the biggest troublemakers. F 8. Breads that are brown in color have more fiber than white bread. F 9. Some foods labeled sugar-free actually contain calorie-bearing sugars. T 10. Artificial sweeteners are safe to consume in moderation. T

Any Questions?