New version page

UC NUTR 1030 - CHO recommendations, functions, digestion/absorption of CHOs, Glycemic Index, Sugar alcohols

Type: Lecture Note
Pages: 6

This preview shows page 1-2 out of 6 pages.

View Full Document
View Full Document

End of preview. Want to read all 6 pages?

Upload your study docs or become a GradeBuddy member to access this document.

View Full Document
Unformatted text preview:

NUTR 1030 1st Edition Lecture 7Outline of Last Lecture I. Identify the major types of carbohydrates and give examples of food sources for eachII. Discuss alternative sweetenersIII. Discuss the functions of carbohydrates in the bodyOutline of Current Lecture I. Carbohydrate recommendationsII. Review CHO functionsIII. Digestion/Absorption of carbohydratesIV. Insulin vs. GlucagonV. Glycemic index and loadVI. CHO-related diseases and health concernsVII. Sugar AlcoholsCurrent LectureCHO Recommendations:Our needs are:- Enough for brain and CNS… 45-65% of total energy intake, assuming adequate diet- RDA set to 130g/dShould also get:- <6% as added sugar (about 12 tsp)- 14g fiber/ 1000 kcalI. About 25g/day for females and 38g/day for malesII. Too much fiber (>60 g/day) not recommendedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Increases fluid needs, can bind minerals, too satiatingCHO Functions:Digestible CHO- Energy: 4 kcal/gI. Both immediate and stored as glycogenII. Glycogen stores are limited- “Protein Sparing”I. Body does not use amino acids to make glucose if CHO intake is adequate- Prevents ketosisII. Body requires CHO for complete breakdown of fatty acids for energyIndigestible CHO:- Promotes bowl health- prevents constipation and hemorrhoids- Reduces risk of obesity- may promote fullness and satiety- Improves blood glucose control- Reduces cholesterol CHO Digestion:- Begins in the mouthI. Saliva contains enzyme- salivary amylaseII. Starch broken down to dextrins and maltose by salivary amylase- StomachI. Stomach acidity stops the action of salivary amylase- Small IntestineI. CHO in the intestines causes the pancreas to secrete pancreatic amylase= breakdown of polysaccharides to dextrins and disaccharides which stimulate:II. Intestinal cells to release enzymes: maltase, sucrase, and lactaseMaltose + Maltase = glucose + glucoseSucrose + Sucrase = glucose + fructoseLactose + Lactase = glucose + galactoseIII. The monosaccharides can then be absorbedCHO Absorption:- Glucose and GalactoseI. Requires a carrier and energy expenditure- Considered active absorption to absorb these molecules- The energy (ATP) is expended to pump the sodium back out of the cellII. Going against the concentration gradient (low to high)- FructoseI. Absorbed by facilitated diffusion using a carrier - No energy expendedII. Most fructose is metabolized to glucose- All monosaccharides are transported via portal vein to liverTransportation/ Absorption of Monosaccharides:- Portal vein transports absorbed monosaccharides to liver- Liver can:I. Transform fructose and galactose to glucoseII. Release glucose back to the bloodIII. Store glucose as glycogenIV. Transform glucose to store as fat- Insulin (released by pancreas into blood)I. Role in cellular glucose absorptionII. Binds to membrane receptorIII. Stimulates transporter to move to cell membrane- So glucose can be absorbed into cell- Maintenance of blood glucose levelsI. Key roles of liver and pancreasInsulin vs. GlucagonInsulin:- Promotes glycogen synthesis- Increases glucose uptake by the cells- Reduces gluconeogenesis- Net effect: lowers the blood glucoseGlucagon:- Breakdown glycogen- Enhances gluconeogenesis- Net effect: raises blood glucoseGlycemic Index and Load:Glycemic Index:- Ratio of a blood glucose response compared with a standard- Based on a 50 gm carbohydrate servingGlycemic Load:- Amount of carbohydrate in a food multiplied by glycemic index and divided by 100- More accurately reflects blood glucose impactWhat negative effects can a high GL have?- Stimulates the release of insulin- Insulin increases blood triglycerides level- Insulin increases LDL- Insulin increases fat synthesis- Increases risk for CVD- Returns to hunger quickerDietary CHO Related Diseases and Health Concerns:- Dysfunctional CHO metabolism: diabetes mellitus, metabolic syndrome and hypoglycemia- Dietary fiber: diverticulosis and diverticulitis- Lactose: malabsorption/ intolerance- Fructose: malabsorption/ intolerance- Sugar alcohols: GI distressDiabetes Mellitus:- Dysfunctional CHO metabolismType 1 Diabetes Mellitus:- Insulin producing cells in pancreas are destroyed (autoimmune disease)I. Insulin therapy required for life- Diet must be coordinated with insulinI. Exchange system, carbohydrate counting- Increased risk for cardiovascular disease, blindness and kidney diseaseType 2 Diabetes Mellitus:- Progressive disease- Characterized by insulin resistanceI. Insulin production may be low, normal or high- Most common type of diabetes (90% of cases)- Treatment:I. DietII. Physical activityIII. MedicationsOther Blood Sugar Disorders:- Metabolic SyndromeI. Group of factors that increase risk for type 2 diabetes and cardiovascular disease- HypoglycemiaI. Reactive Hypoglycemia II. Exaggerated insulin response after eating- Fasting HypoglycemiaI. Low blood sugar after fasting- Lactose IntoleranceI. Occurs with insufficient lactase productionII. Lactose is undigested and not absorbedIII. Lactose is metabolized by large intestinal bacteria- Causes gas, bloating, cramping, discomfortIV. Most people can tolerate “some” dairy- ½- 1 cup milk, hard cheese, yogurtV. Can be primary or secondary- Fructose IntoleranceI. Capacity to absorb dietary fructose (via facilitated diffusion) is limited- Some individuals are able to absorb less at one time- Unabsorbed fructose passes unabsorbed to the large intestine and is fermented by bacteria (symptoms similar to lactose intolerance)II. Treatment- Avoidance of high fructose foods or consumption of fructose only as part of a mixed mealSugar Alcohols:What are they?- Not sugars or alcohols:I. Resemble sugars in chemical structureII. Incompletely metabolized- Contribute fewer calories/gram than CHOWhere are they found?- Naturally in fruits and vegetables- Commercially produced and added to “sugar-free” foodsI. Referred to as “sugar alcohols” on nutrition facts panel- The good: do not promote tooth decay, provide fewer calories than sugar, low effect on blood glucose- The not-so-good: partially fermented in large intestineI. Excess consumption may have a laxative effect- >50g/day of sorbitol, >20g/day of mannitol “may cause


View Full Document
Loading Unlocking...
Login

Join to view CHO recommendations, functions, digestion/absorption of CHOs, Glycemic Index, Sugar alcohols and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view CHO recommendations, functions, digestion/absorption of CHOs, Glycemic Index, Sugar alcohols and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?