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Patty Maloney MSN/Ed,RN

Key Concepts

Carbohydrate foods provide energy (calories)

Carbohydrates are readily available and usually low cost

Carbohydrate structures vary from simple to complex to provide both quick and extended energy for the body.

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Key ConceptsCarbohydrates = Primary fuel source,

Major source of ENERGY

Carbohydrates – break down rapidly

The term energy is used interchangeably with calorie, kilocalorie, kcal

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Carbohydrates

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CarbohydratesAre widely available and easily

grownRelatively low in costMay be easily storedApproximately ½ of total calories in

American diet come from carbs.

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Carbohydrates To produce energy, the body: 1. Digests the carbohydrate (fuel)

and changes it to glucose 2. Absorbs and carries this fuel to

cells in need3. Energy is burned and released

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Carbohydrates

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved. 7

Classes of CarbohydratesMonosaccharides (one molecule C6H12O6)

Disaccharides (two molecules C6H12O6)

Polysaccharides

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Classes of CarbohydratesMonosaccharides – building block of all carbs

Simple, single sugarSimple carbohydrate

Glucose (also known as dextrose) supply comes from digestion of starch All sugars convert to glucose in the blood

Fructose Found in fruits, honey – very sweet High fructose corn syrup – soda, canned goods,

processed foods Galactose

From digestion of milk sugar

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Classes of Carbohydrates, cont’dDisaccharides

Double sugarSimple carbohydrate

Sucrose – table sugarPowdered, granulated, brown sugar

LactoseSugar found in milk

MaltoseNot found in diet, results as a breakdown

product of starchUsed as a sweetenerFound in beer, malt products, infant

formula

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Classes of Carbohydrates, cont’d

Polysaccharides = complex carbs

StarchGlycogenDietary fiber

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Starch

Most important polysaccharide in the diet- Sources (grains,

legumes,potatoes,rice)- Complex CHO

Legumes = beans, peas, lentilsEnriched grains are refined grains that

have nutrients added back to them (ie: iron, riboflavin, vitamin A)

Whole grains – keep outer bran layer, high fiber

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Kernel of Wheat

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GlycogenNot a significant CHO source in the dietStorage form of carbohydrates in the body –

for about 24 hours, stored in the liver and muscles.

Stored in liver & muscles – it is “recycled” Storage form of quick energy

Helps to maintain normal blood sugar throughout day & night

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FiberType of polysaccharide

Soluble (helps to lower cholesterol & weight) Beans, oatmeal, barley, broccoli, citrus fruits

Insoluble (provides bulk in GI tract) Stems/leaves of vegetables, bran, whole grains

Indigestible carbohydrate – humans lack enzyme needed to digest fiber

Important for digestion and health of GI tract (gastrointestinal)

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FIBERRecommended daily intake = Men – 38 grams

Women – 25 grams

Reduced for people over 50 yrs. – Men – 30 grams Women – 21 grams

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SweetenersNutritive sweeteners

Sugar alcohols (sorbitol, mannitol, xylitol)Have caloric value

Nonnutritive sweetenersArtificial sweeteners in food (aspartame,

saccharin)Have no caloric value

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Function of CarbohydratesBasic fuel supply

Energy for physical activities and all work of body cells

Reserve fuel supplyProvided by glycogenMaintains normal blood glucose level

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Special Tissue Functions of Carbohydrates

LiverStores glycogen - to protect cells from

depressed metabolic functionBack up energy source

Protein and fatCarbohydrates protect (regulate) proteins and

fat – allows them to be used properly for tissue building

Spares body protein from being used for energy

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Special Tissue Functions of Carbohydrates, cont’dHeart

Glycogen is vital emergency fuel for heart muscle

Central nervous systemBrain dependent on minute-to-minute supply of

glucoseEnhances learning and memory

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Food Sources of Carbohydrates

StarchesProvide important complex carbohydrates, key

to a good diet !Important source of fiber

SugarsHigh-sugar diets carry health risksAverage American eats 10 tablespoons per day

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Food Sources of Carbohydrates1 slice white bread 12 grams1 cup pasta 39 grams1 cup skim milk 12 grams1 soda (cola) 35 gramsSkittles (2 oz.) 52 gramsDried fruit (5 oz.) 93 grams1 tsp. sugar 4.5 grams

RDA = 130-150 grams per day

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High Fructose Corn SyrupSweetener – from cornAverage annual intake = 60 lb. per personIncreases triglycerides and body fatLeads to increased cravings

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Body Needs for CarbohydratesDietary Reference Intakes

45% to 60% of adult’s total caloric intake should come from carbohydrate foods

Approximately 130 -150 gm per dayLimit sugar to no more than 25% of calories

consumedDietary Guidelines for Americans, 2005

General guidelines: fiber rich foods, whole grains, reduced sugar or no-added sugar, non-caloric sweeteners, oral hygiene

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