Carbohydrates Chapter 3 Learning Objectives Identify food sources

Carbohydrates Chapter 3

Learning Objectives ● ● ● ● Identify food sources of carbohydrates and distinguish between simple and complex carbohydrates. Compare and contrast glucose, fructose, sucrose, and lactose. Identify sugars on an ingredient label, foods high in added sugars, and the number of teaspoons of sugar in a food using a food label. Identify the simple sugar found in starch and fiber, list four foods rich in starch, and explain gelatinization and how starch is used in cooking. Identify examples of high-fiber foods and explain the difference between soluble and insoluble fiber, and between dietary fiber and functional fiber. Distinguish between a whole grain and a refined grain and explain why a whole grain is more nutritious. Summarize the functions of carbohydrates and describe how glycogen functions in the body. Describe how carbohydrates are digested and absorbed in the body, and explain how the body regulates the level of glucose in the blood. © 2013 John Wiley & Sons, Inc. All rights reserved.

Learning Objectives (cont’d) ● ● ● ● Identify foods with low to medium glycemic loads and how a low glycemic diet might affect your health. Discuss current recommendations for carbohydrate, sugar, fiber, and intake of fruits, vegetables, legumes, and whole grains. Explain the health effects (if any) of added sugars on dental cavities, obesity, diabetes, heart disease, hypoglycemia, and hyperactivity in children. Demonstrate how to select whole grains, and list two ways eating whole grains can improve your health. Define lactose intolerance and describe three strategies to manage it. Describe how to cook whole grains and legumes and use them on the menu. Create an appetizer, entrée, side dish, salad, and snack using high-fiber carbohydrate foods. Read food labels to identify foods using alternative sweeteners © 2013 John Wiley & Sons, Inc. All rights reserved.

Introduction to Carbohydrates are a large class of nutrients including: ◦ sugars ◦ starch ◦ and fibers that provide most of the energy for your body. ● Most carbohydrates are found in plants. ◦ Photosynthesis is a process in which plants use energy from sunlight to convert carbon dioxide (CO 2 ) and water (H 2 O) to carbohydrate (C 6 H 12 O 6) ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Types of Carbohydrates Simple carbohydrates = Sugars ◦ Examples: ● Fructose in fruit (natural) ● Table sugar (processed) ● Complex carbohydrates = Starch = Fiber ◦ Complex carbs contain chains of many sugars. ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Simple Carbohydrate (Sugars) ● Simple carbohydrates include: ◦ Monosaccharides = single sugar ●Glucose ●Fructose ●Galactose ◦ Disaccharides = two sugars bonded together ●Sucrose ●Maltose ●Lactose © 2013 John Wiley & Sons, Inc. All rights reserved.

© 2013 John Wiley & Sons, Inc. All rights reserved.

Simple Carbohydrates Glucose ◦ The most abundant sugar found in nature ◦ Most important source of energy for us and for plants ◦ Blood glucose level—vital to health and energy ◦ Found in fruits and honey (and many plant foods) ● Fructose ◦ The sweetest natural sugar ◦ Found in fruits and also honey ◦ Found in high fructose corn syrup used in sodas, candy, and other foods ● Galactose ◦ Found in milk linked to glucose ● Rarely seen by itself ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Disaccharides = Double Sugars ● Sucrose = table sugar ◦ Raw sugar is made from sugar cane and sugar beets. This raw sugar must be further refined for human consumption. ◦ White sugar provides virtually no nutrients for its 16 kcalories/teaspoon. ● Lactose = milk sugar ◦ The least sweet ◦ One of the few carbs associated exclusively with animal products ● Maltose = “yeasty” sugar ◦ Does not occur naturally to an applicable degree ◦ “malt”, bread sugar, alcohol sugar © 2013 John Wiley & Sons, Inc. All rights reserved.

Relative Sweetness of Sugars and Artificial Sweeteners © 2013 John Wiley & Sons, Inc. All rights reserved.

Added Sugars and How They Affect Your Health ● You find added sugars in: ◦ Beverages: ●soda, fruit drinks, sweetened teas and lemonade, and many sports drinks, vitamin waters, and energy drinks ◦ Desserts and snacks: ●cookies, cake, ice cream, baked goods ◦ Sweet pickles, ketchup and other condiments ● Sugar and high-fructose corn syrup are equally harmful in excess. © 2013 John Wiley & Sons, Inc. All rights reserved.

Examples of Added Sugars ● ● ● Confectioner’s sugar Molasses White and brown sugar Maple and turbinado sugar Fructose Corn syrup ● ● ● High-fructose corn syrup Honey Maple syrup Brown rice syrup Agave nectar/syrup © 2013 John Wiley & Sons, Inc. All rights reserved.

Functions of Sugar in Cooking/Baking ● ● ● Sugar helps balance the acidity of ingredients such as tomatoes and vinegar. Sugar browns the crust in baking (caramelization) Sugar helps retain moisture in baked goods so they stay fresh and moist Sugar affects texture, tenderizing in baked goods Sugar acts as a food for yeast in breads. © 2013 John Wiley & Sons, Inc. All rights reserved.

One teaspoon sugar = 4 grams ● “Sugars” on the Nutrition Facts panel includes natural and added sugars. If the label says “ 40 grams” under sugar, then: 40 grams of sugar = 10 teaspoons sugar 4 grams sugar/1 teaspoon = ALMOST ¼ CUP!!! © 2013 John Wiley & Sons, Inc. All rights reserved.

Complex Carbohydrates Polysaccharides ◦ Includes starch and fiber ● Facts about starch: ◦ Plants store glucose in the form of starch. ◦ Starch is a chain of hundreds to thousands of glucose molecules linked together. ◦ Starch is only found in plant foods. ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Starches as Thickeners When heated in liquid, starch gelatinizes. ◦ The starch molecule swells, taking up more room, thus thickening the liquid ● Gelatinization is a process unique to starches, and so you find starches frequently used as thickeners in soups, sauces, gravies, puddings, and other foods. ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Fibers Like starches, fibers are long chains of glucose units bonded together. ● Unlike starches, fiber can’t be broken down by human digestive enzymes. ● Some fiber (called soluble fiber) is digested by bacteria in the large intestine. ● Fiber is not found in meat, poultry, fish, dairy products, or eggs. © 2013 John Wiley & Sons, Inc. All rights reserved.

Two Types of Fiber ● Soluble fiber ◦ Swells in water like a sponge (so you feel full longer after eating). ◦ Some intestinal bacteria digest it. ◦ Soluble fiber lowers your cholesterol. ◦ Oats, barley, beans, ◦ Fruits like apples, pears and citrus ◦ Vegetables like carrots, sweet potatoes and brussels sprouts ● Insoluble fiber ◦ Does not swell in water much. ◦ Intestinal bacteria are less likely to digest it. ◦ Insoluble fiber helps prevent constipation. ◦ Bran and whole grains, beans, peas and lentils ◦ Fruits and vegetables, cabbage, carrots, corn, berries and melon ◦ Seeds and nuts Fiber-containing foods contain both soluble and insoluble fiber. © 2013 John Wiley & Sons, Inc. All rights reserved.

Functions of Carbohydrates 1. #1 source of energy for body (glucose)—brain and nerve cells almost completely rely on glucose for energy. ◦ Burning glucose for energy spares protein. ◦ Burning fat for energy without carbohydrates can be harmful to the body ● When fat is burned as energy, the process is incomplete and ketones are produced ● Too many ketones in the body will acidify the blood and interfere with oxygen transport ◦ You need at least 130 grams of carbohydrates daily to prevent protein and fat from being burned for fuel. You normally eat half your kcalories as carbohydrates. © 2013 John Wiley & Sons, Inc. All rights reserved.

Digestion, Absorption, and Glycemic Response During digestion, enzymes break down starch and disaccharides into sugar units that are then absorbed. (monosaccharaides) ● Fiber is not broken down by enzymes. Some bacteria in the large intestine can digest soluble fiber. ◦ Soluble fiber slows the emptying of the stomach. ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Glycemic Response How quickly, how high, and how long your blood sugar level rises after eating A low glycemic response (meaning your blood sugar rises slowly and not too high) is preferable to a high glycemic response BECAUSE it may decrease your risk factors for heart disease and diabetes. ● Lower glycemic response is also associated with a healthy weight. The gradual add of glucose to the blood stream prevents excess from being converted to fat ● © 2013 John Wiley & Sons, Inc. All rights reserved.

The higher a food’s glycemic load, the higher your blood glucose goes up. High Glycemic Load: ◦ Chocolate cake with frosting, white rice, spaghetti, French fries, cola, jelly beans ● Medium Glycemic Load ◦ Raisin Bran cereal, brown rice, banana, apple juice, white bread, pretzels ● Low Glycemic Load ◦ Whole wheat bread, All-Bran cereal, apple/orange/peach/grapes, peas/carrots, legumes ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Dietary Recommendations for Carbohydrates Americans get enough carbohydrate: 45 to 65 percent of total kcalories. ● But we eat too many: ◦ Added sugars in beverages, desserts, and candy ◦ Refined grains such as white flour in bread or white rice ● And we eat too little: ◦ Vegetables and fruits ◦ Whole grains such as whole wheat ◦ Milk and milk products ◦ Beans, peas, and lentils © 2013 John Wiley & Sons, Inc. All rights reserved.

Carbohydrate Recommendations RDA is 130 grams per day: 1. ◦ This is a minimum so the brain gets enough glucose —we normally eat a lot more than 130 grams/day. Limit intake of added sugars: 2. ◦ ◦ For most women—no more than 100 kcal/day (about 6 teaspoons) For most men—no more than 140 kcal/day (about 9 teaspoons) (American Heart Association) Added sugars include white sugar, high fructose corn syrup and other sweeteners added to foods in processing, as well as sugars added to foods at the table. © 2013 John Wiley & Sons, Inc. All rights reserved.

Carbohydrate Recommendations 3. ◦ ◦ Adequate Intake for total fiber is: 25 grams/day for women (21 g after 50) 38 grams/day for men (30 g after 50) Eat 14 grams of fiber for every 1, 000 kcalories. © 2013 John Wiley & Sons, Inc. All rights reserved.

Added Sugars and Their Health Effects ● ● ● Dental cavities Obesity Diabetes Heart disease Hypoglycemia – associated with diabetes and insulin Hyperactivity in children © 2013 John Wiley & Sons, Inc. All rights reserved.

Added Sugars and Obesity As individuals eat more added sugars, they have a higher risk of becoming obese. ● Children and adolescents who consume more sugar-sweetened beverages have higher body weights compared to those who drink less. ● Kcalories from sugar-sweetened beverages are not as filling as solid foods. Taking in too many added sugars also makes it hard to get in all the required vitamins and minerals you need —this is especially important for children. © 2013 John Wiley & Sons, Inc. All rights reserved.

Added Sugars and Diabetes People with diabetes have either inadequate insulin or insulin that doesn’t work as it normally would to move glucose from the bloodstream into the body’s cells. ◦ The pancreas regulates the supply of insulin ◦ Too much sugar can make the blood acidic and therefore begin to “pickle” the organs ● Higher consumption of sugar-sweetened beverages is associated with a higher risk of developing Type 2 diabetes. ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Added Sugars and Hyperactivity in Children High sugar intake does not cause hyperactivity or ADHA. ● In some children, a hypersensitive reaction to certain foods may trigger ADHD. ● Only about 5% of children exhibit symptoms ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Whole Grains and Health A diet high in whole grains is associated with less weight gain (less starch is converted to sugar) ● A diet high in whole grains reduces your risk of: ◦ Heart disease ◦ High blood pressure and stroke ◦ Type 2 diabetes ● They contain: ◦ Vitamins ◦ Minerals ◦ Antioxidants such as vitamin E that keep body cells healthy ◦ Phytochemicals—substances in plants that promote health ◦ Fiber ● © 2013 John Wiley & Sons, Inc. All rights reserved.

Fiber and Its Health Effects ● A diet high in fiber reduces your risk of: ◦ Heart disease ◦ Type 2 diabetes ◦ Stroke ◦ High blood pressure ◦ Obesity ◦ Some gastrointestinal disorders © 2013 John Wiley & Sons, Inc. All rights reserved.

A diet high in fiber: ● ● ● Improves blood cholesterol levels May reduce blood pressure modestly Decreases risk of developing diabetes Helps keep blood sugar at normal levels Promotes regularity (prevents constipation) Is linked to lower body weights—increases satiety © 2013 John Wiley & Sons, Inc. All rights reserved.

Lactose Intolerance Lactase (enzyme) is deficient so lactose (milk sugar) is not split into its monosaccarhaids in the small intestines. ● Instead it travels to the colon (large intestine), where it attracts water and causes bloating and diarrhea. ● In addition, intestinal bacteria ferment lactose and produce gas. ● Symptoms usually occur within 30 minutes to 2 hours and clear up within 2 to 5 hours. ● © 2013 John Wiley & Sons, Inc. All rights reserved.