Chapter 4 Carbohydrates What Are Carbohydrates Organic compounds

Chapter 4 Carbohydrates

What Are Carbohydrates? • Organic compounds that contain carbon, hydrogen and oxygen (CH 2 O) © Vinicius Tupinamba/Shutter. Stock, Inc. © Mircea BEZERGHEANU/Shutter. Sto ck, Inc. © Ayd/Shutter. Stock, Inc. © Krunoslav Cestar/Shutter. Stock, Inc.

Single Sugars: Monosaccharides and Disaccharides • Monosaccharides: The Single Sugars • Glucose • Found in fruits, vegetables, honey • “Blood sugar”—used for energy • Fructose • Found in fruits, honey, corn syrup • “Fruit sugar” • Galactose • Found as part of lactose in milk

Disaccharides: The Double Sugars • Disaccharides—two linked sugar units • Sucrose: glucose + fructose • “Table sugar” • Made from sugar cane and sugar beets • Lactose: glucose + galactose • “Milk sugar” • Found in milk and dairy products • Maltose: glucose + glucose • Found in germinating cereal grains • Product of starch breakdown

Complex Carbohydrates • Oligosaccharides • Human breastmilk (source of fiber for babies) • Onions, legumes, wheat asparagus, beans • Polysaccharides • Starch • Long chains of glucose units • Found in grains, vegetables, legumes • Glycogen • Highly branched chains of glucose units • Body’s storage form of carbohydrate

Complex Carbohydrates: Fiber • Dietary + Functional = Total Fiber • Indigestible chains of monosaccharides • Nonstarch polysaccharides: long chains • Cellulose, hemicellulose, pectins, gums, mucilages • Lignins • Found in fruits, vegetables, grains, and legumes

#4 Carbohydrate Metabolism • Glucose is key player • Storing glucose as glycogen • Liver storage • Condensation into glycogen • Hydrolysis for release of glucose when needed • Muscle storage • Selfishly hoards glycogen

Carbohydrate Metabolism • Glucose for energy • Fuels most of body’s cells • Preferred source for brain, nerve cells, and developing red blood cells • Cellular breakdown of glucose • Making glucose from protein • Amino acid conversion • Gluconeogenesis

Carbohydrate Metabolism • Ketone bodies from fat fragments • Inadequate supply of carbohydrates • Fat metabolism shifts • Ketone body formation – starvation • Ketosis – acid-base balance • Carbohydrate needs for protein sparing and prevention of ketosis • Using glucose to make fat

#5 Carbohydrate Digestion and Absorption • Mouth • Salivary amylase begins digestion of starch • Stomach - none • Small intestine • Pancreatic amylase completes starch digestion • Brush border enzymes digest disaccharides • End products of carbohydrate digestion • Glucose, fructose, galactose • Absorbed into bloodstream • Fibers are not digested but are excreted in feces

Carbohydrate Digestion and Absorption

#6 The Constancy of Blood Glucose • Steady supply in blood stream • Intestines – food • Liver – glycogen • Blood glucose homeostasis • Insulin • Glucose from blood into cells • Glucagon & epinephrine • Brings glucose out from storage

The Constancy of Blood Glucose • Balancing within the normal range 70 -110 mg/dl • Balanced meals at regular intervals • Diabetes • Insulin is either inadequate or ineffective • Type 1 diabetes • Type 2 diabetes • Hypoglycemia – usually results from uncontrolled diabetes or other conditions

The Constancy of Blood Glucose • Glycemic response • Speed of glucose absorption, level of blood glucose, and return to normal glucose levels • Low glycemic response • Desired

Carbohydrates in the Body: Homeostatsis Regulating Blood Glucose Levels

Regulating Blood Glucose Levels Hormones: • Insulin – lowers • Glucagon increases • Epinephrine – increases in emergencies © Photodisc

Ketosis Causes: • • Starvation Chronic alcoholism Uncontrolled diabetes Low fluid intake Low carb diets Blood becomes acidic and body dehydrates Minimum 50 -100 mg carbs needed daily to prevent ketosis • Death occurs within 3 weeks if body remains in this state

Symptoms of Ketosis: • • Lethargic and fatigue Nausea and vomiting Constipation Acetone breath from high blood acidity

#7 Hyperglycemia • High levels of glucose in the blood • Obtain Proper diagnosis and causes of high blood glucose • Eat a proper consistent carbohydrate diet and possible diabetes medications

Lactose Intolerance • Symptoms of intolerance • Gas, bloating, diarrhea • Prevalence • • • Genetically determined 98% Thais 95% African American 93% Chinese 12% Caucasian

Lactose Intolerance • Dietary changes • Manage dairy consumption rather than restriction • GI bacteria • Fermented milk products, (Lactaid products) • Individualized diets

#8 What is the glycemic index? • Number classification of foods based on their potential to raise blood glucose levels • Not a reliable method as a snicker bar is classified as low glycemic as 55 but that is NOT a healthy choice for a diabetic or someone wanting to loose weight • Snickers bar • 250 cals, 33 carbs, 12 g fat, 4. 5 g sat fat, 1 gm fiber

#9 Inadequate Regulation of Blood Glucose Levels: Diabetes Mellitus • Diabetes mellitus • Body either does not produce enough insulin or does not use insulin properly • Both genetics and environmental factors seem to be involved • Type 1 – no insulin is produced – insulin injections are required with diet • Type 2 – some insulin may be produced – may be controlled by diet and/or medications • See Diet and Health chapter for more information on DM

#10 Functions of Carbohydrates in the Body • Normal Use of Glucose • • • Using Glucose for Energy Storing Glucose as Glycogen Sparing Body Protein Preventing Ketosis Brain cells and red blood cells require a constant supply of glucose

#11 Carbohydrates and Health Effects • • • Sugar and Dental Caries Fiber and Obesity Fiber and Type 2 Diabetes Fiber and Cardiovascular Disease Fiber and Gastrointestinal Disorders Negative Health Effects of Excess Fiber

#12 Recommended Intakes of Starch & Fibers • DRI for carbohydrates • 45 to 65% of energy requirement • RDA for carbohydrates • minimum 130 grams per day • DV: 300 gms per day • Fiber • DV: 11. 5 grams per 1000 -kcalories • DRI: 14 grams per 1000 -kcalories • No UL

Carbohydrates in the Diet • Moderating sugar intake • Use less added sugar (white sugar, brown sugar, honey and syrups) • Limit soft drinks, sugary cereals, and candy • Choose fresh fruits or those canned in water or juice © CSquared Studios/Photodisc

#13 Alternative Sweeteners • Artificial sweeteners • Non-nutritive sweeteners (saccharin, aspartame, sucrolose) • Large doses and adverse effects • Stevia – an herbal product • Generally recognized as safe (GRAS) • Sugar alcohols • Provide kcalories • Not digested, causes diarrhea

TYPES OF FIBER, BENEFITS AND HOW TO INCREASE

Watch Video: High Fiber Video

An Apple a Day… • The old adage, “An apple a day keeps the doctor away” has persisted over time due to actual health benefits from apples. • Apples have a high pectin content, a soluble fiber known to be an effective GI regulator. © Photodisc

#14 Characteristics, Sources, & Health Effects of Fibers

Effects of Excess Fiber • With all of its health advantages, high fiber intake can cause problems, especially in those who drastically increase their fiber intake in a short period of time. • A sudden increase in fiber can cause increased intestinal gas and bloating. • If you increase your fiber intake, you should also increase your water intake to prevent constipation.

#15 Increasing Fiber Intake • To increase your fiber intake, eat more breads, cereals, pasta, rice, fruits, vegetables, and legumes. • Eat fruits and vegetables with the peel, if possible, as this is high in fiber. • Add fruit to muffins and pancakes. • Add legumes, such as lentils and pinto, navy, kidney, and black beans to casseroles.

Fiber in Selected Foods

Fibers in Selected Foods

• Remember daily recommendation for fiber intake is 14 g per 1000 calories.