The Carbohydrates:

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Chapter 4

• The Carbohydrates
• Sugars
• Starches
• Fiber

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Objectives for Chapter 4

• Explain why the body needs carbohydrates.
• Distinguish between simple carbohydrates and
  complex carbohydrates.
• Explain the process of carbohydrate digestion.
• Define the role of insulin in regulating the
  blood glucose level in the body.
• Determine your daily carbohydrate and fiber
  needs.
• Know health benefits of fiber.
• How to identify added sugar in the diet.
• Describe the difference between type 1 and type 2
  diabetes.
• Know the complications of poorly controlled
  diabetes.

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What Are Carbohydrates?

• Found primarily in plant-based foods
• Grains, vegetables, fruits, nuts, legumes
• Carbohydrate-based foods are staples in numerous
  cultures around the world.
• Most desirable form of energy for body
• In form of glucose (-ose carbohydrate)
• Brain and red blood cells especially rely only on
  glucose for fuel source.
• Glucose is most abundant carbohydrate in nature.

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What are Carbohydrates?

• Carbohydrates are made of carbon, hydrogen and
  oxygen atoms (CHO)
• These atoms form chemical bonds that follow the
  laws of nature.

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Carbohydrates

• Types of Carbohydrates
• Simple carbohydrates
• Monosaccharides glucose fructose and galactose
• contain 6 carbon atoms, 12 hydrogen atoms and 6
  oxygen atoms
• Disaccharides maltose, sucrose, lactose

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Monosaccharides

• Glucose -
• hexagon, blood sugar
• One of the 2 sugars in every disaccharide
• Unit from which the polysaccharides/ complex
  carbohydrates are made

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Monosaccharides

• Fructose
• Has same chemical formula as glucose, but
  different structure
• Sweetest sugar (this is why it is the most
  commonly found sugar in soft drinks)
• Found naturally in honey and fruits

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Monosaccharides

• Galactose
• Binds with glucose to form lactose, found in milk
• Does not exist alone, always with glucose

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Disaccharides

• 2 monosaccharides bonded together to form
  disaccharides
• Occur through 2 chemical reactions
• Condensation water molecule joins 2
  monosaccharides together
• Hydrolysis water molecules splits to break
  apart a disaccharide into two monosaccharides

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Disaccharides

• Sucrose - Found in table sugar, cane sugar,
  fruits and vegetables
• glucose fructose

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Disaccharides

• Maltose - Glucose and glucose combine together to
  form
• Found only in small amount in foods
• It is a product of starch/polysaccharide breakdown

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Disaccharides

• Lactose - Glucose and galactose bonded together
• Milk sugar

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Complex Carbohydrates?

• Polysaccharides
• Long chains and branches of sugars linked
  together.
• There are three types
• Starch, fiber, and glycogen
• Starch is the storage form in plants.
• Amylose straight chains of glucose units
• Amylopectin branched chains of glucose units

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Complex Carbohydrates

• Glycogen
• Storage form of carbohydrate in animals and human
• Found in liver and muscles
• Important source of glucose for blood
• Not a significant food source of carbs
• Highly branched (easy to breakdown to glucose for
  energy)

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Complex Carbohydrates

• Starches
• Storage form of glucose in plants
• Found mainly in starchy vegetables, fruits,
  grains, legumes and tuber (Yams and potatoes)
• Branched and unbranched

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Complex Carbohydrate

• Fiber is part of plant that we eat but cant
  digest
• Examples cellulose, hemicellulose, lignins,
  gums, pectin
• Humans lack digestive enzyme needed to break down
  fiber.
• Dietary fiber naturally found in foods
• Functional fiber added to food for beneficial
  effect
• Example Psyllium added to cereals
• Total fiber dietary fiber functional fiber

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Complex Carbohydrate

• Fibers
• Slows down the process of chewing and stimulates
  production of saliva
• Fiber is classified by its affinity for water
• Soluble fiber
• Non-soluble/insoluble fiber

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Complex Carbohydrate

• Soluble fiber
• found in fruits, oats, barley, beans
• dissolves in water and is fermented by intestinal
  bacteria
• Many are viscous, have thickening properties
• Move more slowly through GI tract
• Delays glucose absorption
• Decrease Cholesterol

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Complex Carbohydrate

• Non-soluble/insoluble fiber
• found in whole grains, cereals, vegetables
• cellulose, hemicellulose, lignins
• Move more rapidly through GI tract, laxative
  effect
• Increase fecal weight which promotes bowel
  movements
• Slows starch breakdown and delays glucose
  absorption in the blood

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Why Is Fiber So Important?

• Fiber helps lower risk of developing
• Constipation
• Diverticulosis, diverticulitis
• Obesity high-fiber foods add to satiation
• Heart disease soluble fibers lower elevated
  blood cholesterol levels
• Colorectal cancer
• Diabetes mellitus slow digestion and absorption
  of glucose

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Digestion of CHO

• The goal of carbohydrate digestion is to make
  glucose for energy
• You digest carbohydrates in your mouth and
  intestines.
• Mouth
• Chewed and moistened with saliva to become bolus
• Saliva contains amylase enzyme (-ase enzyme)
  starts the breakdown of starch into smaller
  polysaccharides

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Digestion of CHO

• Stomach
• Gastric acid (HCL) deactivate amylase
• HCL help break down starch further
• No enzymes are active here on carbohydrate
• Fiber sits here and delays stomach emptying
• Food has now become Chyme

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CHO Digestion

• Small intestine
• Performs most of the carbohydrate breakdown
• The pancreas secretes pancreatic amylase to break
  down polysaccharide into glucose chains
• Maltase, sucrase, lactase enzymes breaks down the
  disaccharides
• The intestinal cells then absorb the
  monosaccharides which go to the blood and then to
  the liver via the vascular system

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CHO Digestion

• Large intestine
• 1-4 hrs after eating, most sugar and starch is
  digested
• A small amount of starch and fiber remain
• Fiber attracts water which softens the stool
• Rectum
• Holds waste until excretion

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From Carbohydrates to Glucose
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Absorption of CHO

• Some CHO is absorbed through the lining of the
  mouth (mostly maltose)
• Most absorption takes place in the small
  intestine
• Then goes into the blood and liver where the
  cells take up fructose and galactose and convert
  it to glucose

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Lactose Intolerance

• Lactose
• principal carbohydrate found in dairy products
• People with a deficiency of the enzyme lactase
  cannot digest lactose properly.
• Lactose maldigestion is natural part of aging
• As soon as baby stops nursing, body makes less
  lactase
• Lactose intolerance
• when lactose maldigestion results in nausea,
  cramps, bloating, diarrhea and flatulence
• Common mostly with Native Americans and African
  Americans

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Lactose Intolerance

• Dietary Changes
• Gradually add dairy products to your diet
• Eat smaller amounts throughout day rather than
  large amount at 1 time
• Try reduced-lactose milk and diary products
• May tolerate up to 1 cup of milk per day
• May tolerate yogurt, acidophilus milk, hard
  cheese and cottage cheese
• Increase intake of calcium fortified foods

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How the Body Use Carbohydrates?

• Glucose supplies energy for body, required for
  brain, nervous system, red blood cells
• Fat can provide fuel for muscle, other tissues
• Hormones regulate amount of glucose in blood
• Insulin is released by pancreas in response to
  high blood glucose levels after a
  carbohydrate-heavy meal
• Directs conversion of glucose in excess of
  immediate energy needs into glycogen in liver and
  muscle cells (limited capacity)
• Rest of excess glucose converted to fat

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Glucose in the body

• Stored as glycogen in the body
• 1/3 in the liver
• Liver glycogen stores depleted after about 18
  hours
• 2/3 in the muscle
• Glycogen can be broken down easily to make
  glucose for energy
• Glycogen in the muscle stays there to fuel
  exercise and day-to-day activities

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Glucose in the Body

• Liver can make glucose from protein in the
  absence of adequate glucose
• Gluconeogenesis breaking down of protein from
  muscle by the liver to make glucose liver
• Protein-sparing action
• having adequate carbohydrate in the diet to
  prevent the breakdown of protein for energy.

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Glucose in the Body

• Without glucose, fat cant be broken down
  completely and ketone bodies are produced, which
  are acidic.
• Ketosis elevated blood levels after fasting
  about two days
• The brain uses glucose only for energy.
• Brain switches to using ketone bodies for fuel to
  spare protein-rich tissues.
• If fasting continues, protein reserves are
  depleted and death is inevitable.

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Maintaining Normal Blood Glucose

• Normal blood glucose
• 70-110mg/dL
• Regulating hormones
• Insulin moves glucose from blood stream after a
  meal
• Glucagon brings glucose to the blood stream
• Epinephrine (adrenaline) increases blood glucose
  levels at times of stress.
• Fight or flight hormone stress, bleeding, low
  blood glucose levels trigger its release

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Insulin Directs Excess Glucose into Storage
High Blood Glucose Levels
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Glucagon Directs release of Glucose into blood
stream
Low Blood Glucose Levels
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What Is Diabetes Mellitus?

• Diabetes mellitus
• individual has high blood glucose levels due to
  insufficient insulin or insulin-resistance
• Glucose cant enter cells, which burn fat for
  fuel
• Without glucose, acidic ketone bodies build up,
  causing life-threatening diabetic ketoacidosis
  untreated can result in coma, death
• Type 1 diabetes 5-10 of cases
• Autoimmune disease insulin-producing cells in
  pancreas destroyed - insulin injections required
• Develops in childhood, early adult years

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What Is Diabetes Mellitus

• Type 2 diabetes 90-95 of cases
• Cells are resistant to insulin,
• pancreas decreases production of insulin and
  medication and/or insulin is required
• People 45 and older or at risk for diabetes
• Now seen in increasing number among overweight
  and obese children
• Prediabetes glucose intolerance
• Blood glucose higher than normal but not high
  enough to be classified as Diabetes

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What Is Hypoglycemia?

• Hypoglycemia blood glucose level below 70 mg/dl
• Symptoms hunger, shakiness, dizziness,
  perspiration, light-headedness
• May occur in people with diabetes when they dont
  eat regularly to balance effects of insulin or
  blood glucose-lowering medication
• Can cause fainting, coma

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Interpreting Blood Glucose Levels
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What Is Diabetes Mellitus?

• Diabetes can result in long-term damage
• High blood glucose levels damage vital organs.
• Nerve damage, numbness, poor circulation
• Infections, leg and foot amputations
• Eye damage, blindness
• Tooth and gum problems
• Kidney damage
• Increased risk of heart disease

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What Is Diabetes Mellitus?

• Blood glucose control is key
• Nutrition and lifestyle goals
• Physical exercise
• Well-balanced diet containing
• High-fiber carbohydrates from whole grains,
  fruits, vegetables
• Low-fat milk
• Adequate lean protein sources
• Unsaturated fats
• Total calories important for weight management

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What Is Diabetes Mellitus?

• Cases of diabetes are on the rise.
• Sixth leading cause of death in the U.S.
• Over 200,000 Americans die from diabetic
  complications annually
• Rapidly rising in children
• Obesity, overweight, and physical inactivity
  increase risk
• Preventing type 2 diabetes
• Losing excess weight, physical exercise,
  heart-healthy, plant-based diet

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Health effects Sugars

• Accusations against Sugar
• Causes obesity
• Causes heart disease
• There is no scientific evidence that sugar causes
  misbehavior in children and criminal behavior in
  adults
• There is a theory that sugar increases serotonin
  levels, which can lead to cravings and addiction

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Recommended Intakes

• Added sugars
• DRI - No more than 25 of total daily energy
  intake
• WHO/FDA less than 10 of total daily energy
• For active women 8 tsp of sugar daily
• For active men 18 tsp of sugar daily
• Americans average over 30 tsp of added sugars
  daily.
• Starch
• Minimum - 130 g/day for brain function
• 45 - 65 total daily energy intake

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Recommended Intakes

• Fiber
• 14 grams of fiber per 1,000 calories to promote
  heart health
• Most Americans fall short about 15g/day
• Daily Value 25 g/day
• American Dietetic Association recommends 20-35 g
  per day.
• World Health Organization suggests no more than
  40 g per day.

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Health Effects of Starch and Fiber

• Heart disease
• Type II Diabetes
• Fiber block the absorption of unwanted particles
  in the GI tract
• Colon Cancer removes cancer causing agents from
  the body
• Weight mgt
• Excessive fiber can cause malabsorption, gas,
  diarrhea and abdominal distention

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Grains

• Grains
• Three edible parts bran, endosperm, germ
• Refined grains milling removes bran and germ
• Some B vitamins, iron, phytochemicals and dietary
  fiber lost as a result
• Examples wheat or white bread, white rice
• Enriched grains folic acid, thiamin, niacin,
  riboflavin and iron added to restore some of the
  lost nutrition
• Whole grain foods contain all three parts of
  kernel
• Examples brown rice, oatmeal, whole-wheat bread

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From Wheat Kernel to Flour
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Increasing Intake of Complex carbohydrate

• Grains encourage whole grains
• Vegetables starchy and non-starchy vegetables
  differ in carbohydrate content
• Fruits vary in water, fiber and sugar content
• Milks and Milk Products contain carbohydrate
  cheese is low
• Meat and Meat Alternates meats are low but nuts
  and legumes have some carbohydrate
• Food labels list grams of carbohydrate, fiber and
  sugar starch grams can be calculated.

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• Whole grains at the supermarket
• Sugar and Processed Foods

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Natural and Added Sugars?

• Naturally occurring sugars found in fruits and
  dairy
• Usually more nutrient-dense provide more
  nutrition per bite
• Added sugars are added by manufacturers and are
  often empty calories (provide little
  nutrition).
• Examples soda, candy

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Health effects of Added Sugars

• Carbohydrates play a role in dental caries
• Fermentable sugars and starch feed bacteria
  coating teeth, producing acid to erode tooth
  enamel
• To minimize tooth decay
• Eat three balanced meals daily
• Keep snacking to a minimum, choosing whole fruits
  and raw vegetables
• Include foods that fight dental caries cheese,
  sugarless gum
• Regular dental care and good dental hygiene

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Slices of an Orange versus Orange Slices
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Added Sugars

• Finding the added sugars in your foods
• Sugars on food labels appear under numerous
  different names.
• Honey and fructose are not nutritionally superior
  to sucrose.
• Naturally occurring sugars are not distinguished
  from added sugars on the Nutrition Facts panel.

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Finding Added Sugars on the Label The Many
Aliases of Added Sugar
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Added Sugars on the Label
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Where Are The Added Sugars?
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The Many Sizes of Soft Drinks
A bottle or can of soda can provide from 6 to 17
teaspoons of added sugars, depending on the size
of the container.
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Alternatives to Sugar

• Sugar substitutes are as sweet or sweeter than
  sugar, but contain fewer calories.
• Must be approved by FDA and deemed safe before
  allowed in food products in U.S.
• Saccharin (SweetN Low) 200-700 sweeter than
  sugar
• Aspartame (Nutrasweet, Equal) 200 sweeter
• People with PKU need to monitor all dietary
  sources of phenylalanine, including aspartame.
• Acesulfame-K (Sunette) 200 sweeter
• Sucralose (Splenda) 600 sweeter
• Neotame 7,000-13,000 sweeter

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Sugar Alternatives

• Artificial Sweeteners and Weight Control
• Much research still being done
• Using artificial sweeteners will not
  automatically reduce energy intake.

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Sugar Replacers

• Also called nutritive sweeteners, sugar alcohols,
  and polyols
• Maltitol, mannitol, sorbitol, xylitol, isomalt,
  and lactitol
• Absorbed more slowly and metabolized differently
  in the body
• Low glycemic response
• Side effects include GI discomfort

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Homework/Extra Credit

• 10 points Extra credit
• Find someone who has either type 1 or type 2
  diabetes and interview them by asking the
  following questions. Write a one page typed
  summary of your interview.
• How did you first find out you have diabetes
• What symptoms, if any do you have
• What do you have to do to control your diabetes
  (e.g. insulin, medications, exercise, diet)?
• How else does diabetes affect your day-to-day
  life
• Bring a food label of your favorite cereal to
  class