1. Chapter 4: Carbohydrates

2. Carbohydrate Body’s favorite source of energy
Consists of Monosaccharides, Disaccharides, & Poly- saccharides
Protein sparing. Prevents ketosis
Carbon, Oxygen and
Hydrogen

3. CHO in Food

4. Dietary Carbohydrate Requirement
►55% to 70% of total kcal intake should come from Carbohydrate.
►This is approximately 275 grams to 350g daily if you consume 2000 kcal per day.
Less than 50 grams should be from added sugar (sucrose, HFCS).

5. Monosaccharides “Simple Sugars”
Glucose: Is present in every disaccharide. Makes up polysaccharides exclusively. Blood sugar. All MS are converted to glucose in liver
Fructose: Sweetest of MS. Honey, Fruit
Galactose: Most always bound with glucose. Found in milk. Not very sweet.

6. Disaccharides “Sugars”
Maltose (Gluc + Gluc)
Fermentation
Alcohol production
Sucrose (Gluc + Fruc)
Sugar
Lactose (Galactose + Gluc)
Milk products

7. Formation of Disaccharide
Condensation creates water

8. How Disaccharides are split
Hydrolysis uses water to separate monosaccharides from disaccharides.

9. High Sugar Diets Empty calories Soda replacing milk
Calories adding to excess
Dental caries
exposure to teeth
High glycemic index
Blood glucose response of a given food
Influence by various factors

10. Recommendation for Simple Sugar Intake
No more than 10% of total kcal/day around 50 grams
Reduce intake of fruit juices, fruit “drinks”, and soda.
Avoid sweet, processed food including:
Cakes, pastries, muffins, doughnuts.
Check labels! Sugar is added to a wide range of food and beverages during processing

11. Complex Carbohydrates
Complex Carbohydrates are called “Polysaccharides” There are 3 kinds:
Starch
Glycogen
Dietary fiber

12. Starch Many monosaccharides bound together
Storage form of carbohydrate in plants

13. Glycogen Storage form of CHO for animals and human
Highly Branched. More sites for enzyme action
Found in the liver and muscles

14. Dietary Fiber (Non-starch polysaccharides)
Body cannot break the bonds
Types:
Insoluble (fermentable)
Cellulose
hemicellulose
lignin
Soluble (viscous)
gums,
mucilages
pectin
Resistant starches: beans, unripe bananas, raw potatoes.

15. Foods that Provide Fiber
Insoluble Fiber
Wheat bran
Whole grain breads, cereals
Vegetables
Soluble Fiber
Fruits
Oats
Legumes
However, most foods contain a little of both

16. Soluble and Insoluble Fiber

17. Actions And Benefits of Dietary Fiber
Softens stool and bulks stool
Promotes peristalsis exercise for the intestines. Prevents Diverticulosis.
Fermentation provides SCFA
Delays glucose absorption
Affects transit time of food in GI tract
Insoluble accelerate transit
Soluble slows transit
Soluble fiber can lower blood cholesterol

18. Diverticula

19. Recommended Dietary Fiber Intake
20-35 gm of fiber/day (10-13 gm/1000 kcals)
Children: age +5gm/day
Ave. U.S. intake: ~16 gm/day
Too much fiber (>80 gm/d) will:
require extra intake of fluid
bind to some minerals
develop phytobezoars
Will cause cramps, gas, diarrhea.

20. Phytate Anti-nutrient
Found in foods high in fiber, soy, wheat, seeds, legumes
Binds to ZN, CA, FE, MG, CU
A problem when consuming too much fiber, especially when not use to it.

21. Blood Glucose Regulation
Blood Glucose Regulated by:
Insulin: Stimulates uptake of glucose into the cells. Facilitates storage of glycogen and the conversion of excess carbohydrates to fat
Glucagon: Stimulates liver cells to break down glycogen for glucose or to produce glucose from protein and glycerol. This is called “gluconeogenesis”.
Hypoglycemia
Reactive hypoglycemia
Occurs 2-4 hours after eating a meal
Possibly due to release of epinephrine.
Fasting hypoglycemia
Can occur in healthy people.
Insufficient glucagon.
Hyperglycemia. Too much glucose in the blood stream. Indicative to diabetes.

23. You are a pediatric nurse at a private practice
You are a pediatric nurse at a private practice. A long time patient of yours comes in for a physical. Although Leticia is a healthy and energetic adolescent, today she looks a little pale and fatigued. When you ask her how she is feeling Leticia states that she’s feeling a little shaky and light headed. She also states that she tends to feel this way almost every morning about 2 hours after breakfast, then the symptoms subside within an hour. Concerned with resolving her problem, your ask her what she usually has for breakfast. Leticia replies that she usually has a large plain bagel with jelly, and a glass of juice.
Assume Leticia is telling the truth about what she ate, and that she does not have a biological disorder, what is the likely cause of her light-headedness? What advice would you give her?

24. Glycemic Index
A measurement of glucose response to a particular type of food.
The greater the glucose response, the higher the value. (White bread = 100)
High glycemic foods create high insulin levels
increases fat synthesis and storage
Increases blood triglycerides
Increases hunger
Increases insulin resistance

25. Digestion of Carbohydrates

26. Digestion of Carbohydrate in the Mouth
Saliva contains amylase
Starch is broken down to shorter saccharides
Taste the sweetness with prolong chewing
Proceeds down the esophagus

27. Digestion of Carbohydrate in the Stomach
The acidic environment stops the action of salivary amylase
No further starch digestion occurs

28. In the Small Intestine Pancreatic amylase is released
Intestinal cells release enzymes
Maltose + maltase glucose + glucose
Sucrose + sucrase glucose + fructose
Lactose + lactase glucose + galactose
Monosaccharides are absorbed

29. CHO Digestion

30. Portal Vein Transport absorbed monosaccarhides
Delivers them to the liver
Liver can:
transform them into glucose
release them back into the blood stream
store as gylcogen (or fat)