Carbohydrate digesiton

All 3 types of diabetes result in

high blood glucose due to the inability to regulate blood glucose. High blood glucose = hyperglycemia Uncontrolled diabetes can cause: Nerve & kidney damage Blindness Atherosclerosis

Ketosis

occurs when there is not enough glucose for brain. Fats are broken down during fasting to form ketones. Excess ketones increase blood acidity and cause ketoacidosis which can be harmful to health. Sufficient energy from carbohydrates prevents ketone production as alternate energy source.

The majority of carbohydrate digestion occurs in the

small intestine

AMDA for CHO

Acceptable Macronutrient Distribution Range (AMDR) is 45% to 65% of daily calories.

What is the % associated with the DRI and WHO for sugar?

Added sugar should be less than 25% of total calories.

What is the recommended fiber intake for men and women?

Adequate Intake (AI) for fiber 25 g per day for women 38 g per day for men, or 14 g of fiber for every 1,000 kcal per day

Starch can be

Amylose or amylopectin Amylose is a straight chain and harder to digest Amylopectin has more SA and easier to digest

Glycemic Index

Carbohydrate containing foods have an effect on blood glucose levels. Called glycemic index Foods are rated as either high glycemic index or low glycemic index. High GI = sudden surge in blood glucose & insulin Low GI = slow, steady rise in blood glucose & insulin Foods with a high glycemic index often result in the "blood sugar crash".

What digestion of carbohydrates occurs in the stomach?

Carbohydrate digestion in the stomach is limited to physical digestion. Physical digestion = muscles churn carbs into chyme Chemical digestion = no chemical digestion in stomach

What the food groups provide dietary carbohydrates?

Carbohydrate food sources come mainly from plants: grains, beans, vegetables, fruit, nuts seeds.

What is the difference between dietary fiber and functional fiber?

Dietary fiber is the non-digestible component that naturally occurs in plants. Functional fiber is fiber that has been extracted from plants or manufactured in lab to be used in products. Function fibers have known health benefits Total fiber = Dietary fiber + Functional fiber An individual can use dietary and functional fiber to meet daily fiber needs.

Carbohydrate Digestion

Dietary fibers are the only CHO not digested because the GI tract doesn't have enzymes for fiber. These fibers then move along to the large intestine. "Good gut bacteria" can digest soluble fiber into gas, vitamin K, and short chain fatty acids. Insoluble fiber forms that basis of "fecal bulk" by absorbing and retaining water for fecal material.

Glucagon

Glucagon is secreted by alpha cells of the pancreas when blood glucose levels fall. Glucagon stimulates the liver to breakdown stored glycogen to into glucose. Glucose released into the blood. Also, glucagon stimulates gluconeogenesis when liver glycogen levels run low. Gluconeogenesis = glucose production from amino acids

What are the three monosaccharides

Glucose Fructose Galactose

Sucrose is made up of

Glucose and fructose

Maltose is made up of

Glucose and glucose

Food sources of starch include:

Grains Legumes Vegetables Nuts & Seeds

How are type I and type II diabetes different?

In Type I diabetes, the pancreas doesn't produce enough insulin to lower blood glucose. Often associated with autoimmune disease Lack of insulin results in high blood glucose which is called hyperglycemia. Type I diabetes requires insulin injections to control blood glucose. Type II diabetes results from insulin resistance when cells become less responsive to insulin. Most often occurs in people who are overweight, sedentary, and have family history. Called adult onset diabetes

Insulin

Insulin is secreted by beta cells of the pancreas when blood glucose rises. The purpose of insulin is to lower blood glucose levels. Works by stimulating glucose transporters in cells to remove glucose from the blood. Results in storage of glycogen within the liver and resting muscle.

What are the three disaccharides?

Lactose Maltose Sucrose

Lactose Intolerance

Lactose intolerance occurs when the disaccharide lactose cannot be digested. Variations of intolerance Not a milk allergy Insufficient lactase enzymes to digest the lactose-containing foods. GI symptoms might include: gas, cramping, diarrhea Need alternate sources of calcium other than dairy.

The disaccharidase enzymes produced by the microvilli cells (enterocytes) include:

Maltase Sucrase Lactase The goal of carbohydrate digestion is the breakdown to the smallest absorbable units = monosaccharides. This is the function of intestinal disaccaharidase enzymes.

Carbohydrate Transport

Monosaccharides are water soluble so therefore are transported in the blood. Taken to the liver via the portal vein

What organ regulates blood sugar? What are the hormones involved and what do they do?

Pancreas Insulin and glucagon

Fasting hypoglycemia

Pancreas produces too much insulin, even when someone has not eaten.

Reactive hypoglycemia:

Pancreas secretes too much insulin after a high-carbohydrate meal.

Carbohydrate digestion begins in the mouth with

Physical digestion = chewing Chemical digestion = salivary amylase

What digestion of carbs occurs in the small intestine

Physical digestion = segmentation Chemical digestion #1 = pancreatic amylase Chemical digestion #2 = intestinal disacharidases

The liver processes glucose by?

Releasing glucose into blood Storing glucose as glycogen Using glucose for energy Converting excess glucose to fat (triglycerides)

What are the two different dietary fiber types? What are their functions?

Soluble and insoluble fiber Soluble fiber is a type of fiber that dissolves in water forming a viscous gel. Examples = pectin, gum, mucilage Soluble fiber is associated with reducing cardiovascular disease and type II diabetes. Insoluble fibers do not dissolve in water but do absorb water. Examples = lignins, cellulose, hemicellulose These fibers cannot be fermented by bacteria in the colon. Insoluble fibers promote regular bowel movements, alleviate constipation, and reduce diverticulosis

What are the three types of polysaccharides

Starch (plants) Fiber (plants) Glycogen (animal)

RDA for CHO

The Recommended Dietary Allowance (RDA) is 130 grams/day to prevent ketosis.

Gluconeogenesis

The liver will make "new" glucose from amino acids found in protein if there are not enough CHOs. The source of amino acids for gluconeogenesis come from either: Dietary amino acids Amino acids in muscle tissue

Value of Lower Glycemic Index

There may be a reduction of health risk for heart disease and colon cancer. High fiber intake helps to improve fat levels in the blood (higher HDL and lower LDL)

Glycogen stored in liver is used to maintain

blood glucose levels (blood sugar).

What happens to CHO at the liver/

both fructose and galactose are converted to glucose.

Intestinal disacharidases

breakdown disacharides into monosaccharides.

Pancreatic amylase

digests polysaccharides to maltose.

Lactose is made up of

glucose and galactose

Salivary amylase

works on starches to breakdown polysaccharides to maltose (dissacharide).