1. Carbohydrates
Chapter 3

2. 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.

3. 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

4. Introduction to Carbohydrates
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 (CO2 ) and water (H2O) to carbohydrate (C6H12O6)

5. 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.

6. Simple Carbohydrate (Sugars)
Simple carbohydrates include:
Monosaccharides = single sugar
Glucose
Fructose
Galactose
Disaccharides = two sugars bonded together
Sucrose
Maltose
Lactose

8. 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

9. 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

10. Relative Sweetness of Sugars and Artificial Sweeteners

11. 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.

12. 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

13. 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.

14. 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!!!

15. 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.

16. 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.

17. Fiber is not found in meat, poultry, fish, dairy
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.

18. Two Types of Fiber Insoluble fiber Soluble 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
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
Fiber-containing foods contain both soluble and insoluble fiber.

19. Functions of Carbohydrates
#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.

20. 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.

21. 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

22. 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

23. 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

24. Carbohydrate Recommendations
RDA is 130 grams per day:
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:
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.

25. Carbohydrate Recommendations
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.

26. Added Sugars and Their Health Effects
Dental cavities
Obesity
Diabetes
Heart disease
Hypoglycemia – associated with diabetes and insulin
Hyperactivity in children

27. 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.

28. 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.

29. 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

30. 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

31. 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

32. 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

33. 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.