1. Chapter 4 Carbohydrates: Sugar, Starches and Fiber

2. Carbohydrate
The primary role of carbohydrates is to provide the body with energy (calories).
Why other alternative calorie sources not?
Carbohydrates are the preferred fuel for the brain and nervous system.
Carbohydrates are the ideal fuel compared to other alternatives:
Less expensive than protein.
High-fat diets are associated with chronic disease.
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3. Carbohydrate Basics
Carbohydrate-rich foods are obtained almost exclusively from plants.
Milk is the only animal-derived food that contains significant carbohydrate.
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4. Carbohydrates
“A staple food is a food that can be stored for use throughout the year and forms the basis of a traditional diet” (Wikipedia).
Staple foods are different from place to place
Inexpensive starchy foods
High energy (Calories) and mainly source of energy
As part of every meal
Name may be used synonymously with "food“
Main source of energy and have a primary place in diet
Ancestors: unrefined sugar/ natural source or less processing
Now: most refined/ Less unrefined
Recommendation: more unrefined source like whole grain, veg, fruits
Whole grain: example
Outcome: obesity and chronic disease

5. Complex Carbohydrates
Staple grain: a grain used frequently or daily in the diet. Examples include:
Corn in Mexico
Rice in Asia
Wheat in Canada, Europe and USA
Millet, rye, barley, and oats
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6. Complex Carbohydrates
Refined: refers to the process by which the coarse parts of food products are removed.
For example, the refining of wheat into flour involves removing three of the four parts of the kernel—the chaff, the bran, and the germ—leaving only the endosperm.
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7. Carbohydrates in Our Diet
Carbohydrates make up most of the energy in a healthy diet.
Grains are sources of carbohydrates.
Refined carbohydrates lack fiber and many rich nutrients.
Unrefined carbohydrates are healthier to eat.

8. Unrefined and Refined Foods

9. Whole Grains Whole grains are made up of
bran: containing fiber and vitamins
germ: mainly protein and vitamins
endosperm: starch, protein, vitamins, and minerals

10. The Wheat Kernel: A Whole Grain
Germ: the nutrient-rich and fat-dense inner part of a whole grain.
Endosperm: provides energy; contains starch grains embedded in a protein matrix.
Bran: the fibrous protective covering of a whole grain and source of fiber, B vitamins, and trace minerals.
Husk: (chaff) the outer, inedible covering of a grain.
© 2007 Thomson - Wadsworth

11. Enriched
Example Thiamin and iron
Vit E and B6

12. Complex Carbohydrates
Whole grain: refers to a grain that is milled in its entirety (all but the husk), not refined.
Whole grains include wheat, corn, rice, rye, oats, amaranth, barley, buckwheat, sorghum, and millet; two others—bulgur and couscous—are processed from wheat grains.
© 2007 Thomson - Wadsworth

13. Carbohydrates
Enriched: refers to a 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.
Fortified foods: foods to which nutrients have been added. Typically, commonly eaten foods are chosen for fortification with added nutrients to help prevent a deficiency of a nutrient (iodized salt, milk with vitamin D) or to reduce the risk of chronic disease (juices with added calcium).
© 2007 Thomson - Wadsworth

14. © 2007 Thomson - Wadsworth

15. Empty Calories
Many processed/ready to eat foods contain added sugar that reduces nutrient density (empty calories)
Refine sugar
16% diet
Refined sugar: fiber-, vit-, minerals-, other substances-
Example unrefined: milk, fruit, veg, Question page 89

16. Carbohydrates: Group of components made up of one or more sugar unit
Sugar unit: A sugar molecule that can not be broken down to yield sugar
Sugar unite: contain Carbon, Hydrogen, Oxygen
The proportion of the hydrogen to oxygen is 2:1
H2O

17. Types of Carbohydrates:
Monosaccharide: A carbohydrate made up of a single sugar unit
Disaccharide: A carbohydrate made up of two sugar units
Polysaccharide: A carbohydrate made up of many sugar units linked together.

18. Types of Carbohydrates
Glucose, fructose and galactose are simple carbohydrates.
Glucose is the blood sugar and found in cells.
Sucrose is made up of a molecules of glucose and a molecule of fructose is a disaccharide.
Maltose is made up of two glucose molecules.
Lactose contains one glucose and one galactose.
Galactose: milk
Fructose: fruit

19. Monosaccharides Most common form Contain 6 carbon 12 hydrogen 6 oxegen
C6 H12 O6
Different in the arrangement of the atoms

20. Carbohydrate Complex carbohydrates Simple carbohydrates
Starch
Fiber
Glycogen (animal)
Simple carbohydrates
Simple carbohydrates have one or two molecules of single sugars.
Naturally occurring sugar(fresh fruits, vegetables, milk)
Added sugars in concentrated form
P.Aasassi/Fall 2009

21. Dissaccharides
Simple carbohydrates have one or two molecules of single sugars.
maltose, sucrose and lactose are simple carbohydrates (two units)
Glucose, galactose and fructose are single carbohydrates (two units)
Glucose is the blood sugar and source of energy from carbohydrates (one unit)
Galactose is milk sugar important in producing milk in lactating women and animals (one unit)

22. Dissaccharides
Most common disaccharides are

23. Complex Carbohydrates
Complex carbohydrates contain many molecules of glucose.
Starch, glycogen and cellulose are complex carbohydrates.
Starch and glycogen are synthesized by a chain of glucose molecules joined by alpha 1–4 and 1–6 bonds they also have branched chain attached.
Fiber (cellulose) is a chain of glucose molecules joined by beta 1–4 bond that human intestine does not produce the enzyme to digest it.
Not sweet-tasting that the way simple carbohydrate are

24. Complex Carbohydrates
Glycogen: Storage form of glucose in human and other animals
Liver and muscles
Starch: Glucose molecules linked together
Straight
Branched
Storage form of carbohydrate in plants
Plant growth
Plant reproduction
Fiber: not digest by human, not absorbed
Either, chain
Provide energy
Not absorbed in human small intestine so it pass to large intestine

25. Complex Carbohydrates

26. Glucose is Produced by Plants through Photosynthesis
Photosynthesis: use energy from the sun to convert carbon dioxide and water to glucose. Plants most often convert the glucose to the starch. When we eat plants, Starch is changed to the glucose.

27. Chemistry of Carbohydrates
Starch is stored in the grains, stems and root of the plant.
Fiber is found in the bran of the grains, stem, leaf, and other structures of the plants.
There are two types of fiber in the plant varieties:
Soluble fiber in fruits, oats and legumes
Insoluble fiber mostly in grains and vegetables

28. Soluble and Insoluble Fiber
Pectin
Beans
Pictin: jellies thicken / Soluble fiber around the fruit and vegtables
Gums: thicken /
Soluble fiber can not and small polysaccharides cannot be broken by human digestive enzymes and digest by bacteria.

29. Fiber
Humans do not produce enzyme to digest fiber—therefore, no calories from fiber.
Fiber provides many health benefits to humans:
Insoluble fiber:
provides bulk in the intestine to ease elimination.
prevents constipation, diverticulitis, appendicitis, and may prevent colon cancer.
Soluble fiber:
combines with bile, eliminate it,
preventing elevated blood cholesterol

30. Complex Carbohydrates
Soluble fiber
Around and inside plant cells
Dissolve in the water
Human enzymes can not digest
Broken down by bacteria in large intestine
Pectin, gums, mucilages, some hemicelluloses, and algal substances
© 2007 Thomson - Wadsworth

31. Complex Carbohydrates
Insoluble fiber
Insoluble fibers do not dissolve in water
Structural part of the plant (cell walls)
Unchanged during the digestion
Adds bluk to fecal
Wheat, broccoli and celery
Cellulose, hemicellulose, and lignin.

32. Complex Carbohydrates
Fiber and weight control:
Both type of fibers can help to control weight
Provides satiety (absorb water, delay the empting of stomach)
Prolongs eating time because of chewing of food
Eating fewer empty caloric foods
Page 92 Questions
P.Assassi/Fall 2009

33. Fiber in the Diet Fiber is important, but how much is appropriate?
Harmful effect of too much fiber:
Decrease mineral absorption (especially iron, calcium and zinc).
Feeling of over-fullness and under-consumption of essential nutrients.
Dietary guidelines recommend 14 grams of fiber per 1000 calories. This amount is easily supplied by a diet rich in whole grains, fruits and vegetables (about grams daily)
The wholesale addition of purified fiber is not advised because it can be easily taken to extremes.
Variety of whole grain, legumes, nuts, fruits, and vegetables
P.Assassi/Fall 2009

34. Carbohydrate Digestion & Absorption
Mouth
Small intestine
Digestive enzymes from pancreas
Absorption through the small intestinal villi
Active absorption
Passive diffusion
Large intestine
Elimination of undigested starch and fiber
Modification of intestinal microflora
Role of the pancreas

35. Carbohydrate Digestion & Absorption
Disaccharides and complex carbohydrates
Monosaccharide
Absorbed
Liver (blood)
Not completely digest/ impact overall health

36. Carbohydrate Digestion
Mouth:
starch
first digestive enzyme to work
salivary glands (amylase),
breaking down starch to into the smaller polysaccharide and maltose
Most digestion occur in the small intestine

37. Carbohydrate Digestion
Stomach:
Stomach acid and enzymes
Inactive salivary enzymes by acid
No digestion

38. Carbohydrate Digestion
Small intestine
Most of the digestion (break down to monosaccharide)
Pancreas
enzymes and releases them through the pancreatic duct into the small intestine
Enzyme in the surfaces of the small intestine cells (brush border) break disaccharides into monosaccharide and the cell absorb them

39. Carbohydrate Digestion
Large intestine:
Fiber and other indigestible carbohydrates
Short chain fatty acid and gas
Fatty acid
source of the energy for the cells in the colon, regulating cellular proceeses
Some excreted in the feces
Who does ?

40. Carbohydrate Digestion
Liver and muscles take up surplus glucose to build the polysaccharide glycogen
Muscles hold 2/3 of body’s total store ( use it during the exercise)
Liver stored 1/3 body’s glycogen
When glycogen stores are full and cells’ energy needs are met, the liver then reorganizes these extra energy compounds into fat and it is stored in fatty tissues of the body.
Fat cells can store unlimited quantities of fat.

41. Carbohydrate Digestion

42. Carbohydrate Digestion
Lactose intolerance: inability to digest lactose as a result of a lack of the necessary enzyme lactase.
Symptoms include nausea, abdominal pain, diarrhea, or excessive gas
70 % of the world people
African Americans, Mediterranean, Native Americans, and Asian
Less common in people of northern European
People who are sick or malnourished (developed temporarily)

43. Carbohydrate Digestion
Lactose intolerance:
Enzyme lactase
Lack of the enzyme
Lactose
Large intestine
Gas
Cramp and diarrhea
Prevalence
30 to 50 million of American (African American, Native Americans, Asian American)
Calcium deficiency
Yoghurt and cheese
Lactase tablets

44. Lower lactose food Lower lactose food Yogurt Yogurt Acidophilus milk
Lactose free products
Lower lactose food
Yogurt
Acidophilus milk
Lactose free products
© 2007 Thomson - Wadsworth

45. Glycemic Index
Different carbohydrate containing foods are absorbed at different rate.
Simple carbohydrates and potato starch are absorbed fast and make a large spike in the blood sugar (a high glycemic index) causing a high insulin response.
Beans, legumes and some mixed foods are absorbed slower and have lower glycemic index.

46. Glycemic Index Potato unrefined carbohydrate
Effects of potato on blood sugar is different than effect of kidney beans on blood sugar

47. Glycemic Index
Glycemic index (GI): a scale that ranks carbohydrate-containing foods by how much they raise blood glucose levels compared to a reference food such as glucose or white bread.
The glycemic load (GL) is a measure of the extent to which blood glucose is raised by a given amount of carbohydrate-containing food.
Glycemic effect: the effect of food on a person’s blood glucose and insulin response – how fast and high the blood glucose raises and how quickly the body responds by normalizing.
Time for leaving food from stomach, time for digestion and glucose absorbetion
Glysemic index (white bread= 100, potato 90, kidney 25)
© 2007 Thomson - Wadsworth

48. Glycemic Index Refined sugars and starches Leave the stomach quickly
Digest and absorbed quickly
Greater glycemic response if consume alone
Campare soda with a cup of the soda

49. Carbohydrate Functions
Getting glucose to the cells, role of insulin.
Problems of glucose metabolism
Type 1 diabetes, pancreases loss of insulin producing ability. Autoimmune problem
Type 2 diabetes
increased body fat cells causing resistance to insulin delivery of glucose to the cells
Role of insulin in regulating blood glucose levels

50. Functions of Monosaccharide
Absorbed monosaccharids enter liver where galactose and fructose are converted to glucose.
Glucose enters the blood and circulates.
Insulin helps glucose enter the cells for energy.
Glucagon helps excess blood glucose return to liver and muscles to form storage and form
glycogen
Glucose also is a part of genetic DNA, RNA, ATP and other functional molecules in the body.
Brain, red blood cell and few other must have glucose to stay alive.
Concentration of the glucose is regulate by the liver and pancreatic hormones.

51. When a person eats, blood glucose rises
When a person eats, blood glucose rises. High blood glucose stimulates the pancreas to release insulin. Insulin serves as a key for entrance of blood glucose into cells. Liver and muscle cells store the glucose as glycogen. Excess glucose can also be stored as fat.
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52. Later, when blood glucose is low, the pancreas releases glucagon, which serves as the key for the liver to break down stored glycogen into glucose and release it into the blood to raise blood glucose levels
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53. How the Body Handles Carbohydrates
Insulin: a hormone secreted by the pancreas in response to high blood glucose levels; it assists cells in drawing glucose from the blood.
Glucagon (glue-cuh-gon):a hormone released by the pancreas that signals the liver to release glucose into the bloodstream.
© 2007 Thomson - Wadsworth

54. Blood Glucose Regulation

55. Cellular Carbohydrate Metabolism
In cells, glucose is metabolized to produce energy.
There are two pathways for producing energy:
Anaerobic pathway (incomplete metabolism) with production of lactate.
Happens in absence of oxygen. Resulting in lower energy production
Aerobic pathway (complete metabolism) with end products of CO2 and H2O.
Happens when oxygen is present. Produces lot more energy.

56. Cellular Respiration
The first step in cellular respiration is glycol sis
Gylicoysis; a anaerobic metabolic pathway that splits glucose into tow three carbon to make ATP
36 ATP for each glucose (compare 2 and 36)

57. Breakdown of Fat and Protein
In the absence of carbohydrates body breaks down protein to form glucose to feed the brain.
About ½ of amino acids skeletons can produce glucose
Other amino acids produce ketone
acidic molecules that changes the pH of body environment to acid.
Body also breaks down the stored fat to provide energy for body needs
Fat breakdown in the absence of carbohydrates results in ketone production.
Ketone bodies are harmful to the body and are excreted through the urine.
Severe ketosis can occur with untreated diabetes and can cause coma and even death.
3 carbon

58. Ketone Formation

59. Carbohydrates and Health
Are carbohydrates good or bad for you?
What kind of carbohydrates are beneficial to health?
Whole grains, complex carbohydrates foods are healthy carbohydrates.
What kind are not healthy carbohydrates to consume?
Refined carbohydrates and food with added sugar are not healthy and may cause risk of chronic diseases.

60. Diabetes Insulin response is slow or ineffective
Hyperglycemia occurs when blood glucose levels rise too high, glucose fails to get into cells, and blood glucose stays too high for an abnormally long time.
Type 2 diabetes is most common
little insulin, or cellular resistance to insulin.
Type 1 diabetes is less common
production of no or very little insulin
requires insulin injections to control blood sugar levels
incidence of type 2 diabetes is increasing in children and adolescents.
Obesity is the major risk factor for diabetes
P.Assassi/Fall 2009

61. Diabetes
Carbohydrates are generally blamed for diabetes. The interesting fact is again which kind of carbohydrates are to be blamed.
Whole grain and complex carbohydrates prevent type 2 diabetes by preventing fat cells accumulation in the body.
Refined carbohydrates increase empty calories in the diet may cause weight gain, increase resistance to insulin causing type 2 diabetes.

62. Diabetes
Type 1 diabetes is due to lack of production of insulin from pancreas causing blood glucose to elevate.
It can be controlled by a diet very low on fast absorbing starches (potato) and refined sugars.
A diet high in fiber and whole grains help slow absorption and prevent fast rise in blood sugar.
In sever cases insulin must be injected to regulate blood sugar levels.

63. Blood Glucose Levels in Diabetes

64. Diabetes Incidences of diabetes in the US is on the rise.
Certain racial groups are more susptible to diabetes than others.
Lifestyle, dietary habits physical activity and environment also play a role.
Managing diabetes with diet, exercise and medication.
Symptoms and complications of diabetes.

65. Incidence of Diabetes

66. Other Health Problems Hypoglycemia: Dental caries:
Reactive hypoglycemia (high carbohydrate food)
Fasting hypoglycemia
Dental caries:
Dental hygiene
Refined sugars
Carbohydrates and weight management:
Which kind to consume?
(insulin production, respond to insulin)
Small, frequent, low in cho, high in protein

67. Carbohydrates and Weight Management

68. Carbohydrates & Body Weight
Carbohydrates and weight management.
Role of refined carbohydrates in storage of fat.
Role of insulin in body fat accumulation.
The consequence of low or no carbohydrate diets?
Ketosis and ketogenic diets
Role of ketones in weight loss
Benefits and harms of nonnutritive sweeteners.

69. Nonnutritive Sweeteners

70. Carbohydrates and Heart Disease
Diets with high sugar, added sugar glucose or any simple sugar raise blood sugar, cholesterol and the risk of heart disease.
High fiber containing diets with both soluble and insoluble fiber reduce the risk of heart disease.

71. Carbohydrates and Heart Disease
Consuming foods high in soluble fiber reduce cholesterol synthesis by liver.
Soluble fiber in legumes, fruits, oats, brown rice, etc. bind with bile in the intestine, removing it from the body preventing bile reabsorption, and cholesterol re-synthesis.
Soluble fiber may also reduce blood cholesterol by other means.

72. Cholesterol and Soluble Fiber

73. Carbohydrates and Heart Disease
Diets with high insoluble help reduce risk of heart disease by:
Reducing absorption of starch and sugars.
Keeping blood glucose normal
Reducing food intake by filling the stomach and reducing the appetite.
Preventing obesity
Reducing blood pressure.
Preventing formation of diverticula

74. Diverticula

75. Intestinal Health and Fiber
Insoluble fiber is not digested, absorbs water in the intestine and increase in volume conferring benefits:
Softens the stool, making elimination easy.
Preventing constipation, diverticulitis, appendicitis, hemorrhoids, and possibly colon cancer.
Speed up the movement of waste materials from the bowl.
Modify the bowl micro flora environment positively.

76. Meeting Carbohydrate Needs
Carbohydrates intake is to meet the needs of:
Adequate blood glucose levels to meet the brain, red blood cells and nerves energy requirements (about 300 grams/day).
Minimum carbohydrate intake to prevent ketosis
is 100 grams/day
Recommendations are:
45% – 65% of total daily calorie intake should come from complex carbohydrates.
In the US diet, the right percentage of calories consumed from carbohydrates, but it is mostly refined or added sugars.

77. Healthy Carbohydrate Choices

78. Choosing Carbohydrates Wisely

79. End of Chapter 4
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