Carbohydrates - PowerPoint PPT Presentation


PPT – Carbohydrates PowerPoint presentation | free to download - id: 6a9aee-MDRhZ


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation



Carbohydrates ... Carbohydrates – PowerPoint PPT presentation

Number of Views:87
Avg rating:3.0/5.0
Slides: 56
Provided by: Preferred99


Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Carbohydrates

Roles of Carbohydrates
  • Definition organic substance made of carbon,
    hydrogen, and oxygen that supplies the bodys
    main source of energy
  • Macronutrient
  • Direct energy source- 4 kcal per gram
  • Adequate carbohydrate intake preserves tissue
  • Fuel for the central nervous system (CNS) and red
    blood cells
  • Prevents ketosis

Role of Carbohydrates
  • Sufficient carbohydrates prevent the rapid
    breakdown of fat that would produce ketones
  • Ketones are chemicals produced by the liver when
    the body cannot use glucose and must break down
    fat for energy
  • Ketones can poison and even kill body cells.
  • When ketones build up, the body gets rid of them
    in the urine
  • Ketosis slows down fat metabolism

  • During long-term starvation, proteins in the
    muscles, heart, liver, kidneys and other vital
    organs break down into amino acids and certain
    forms are turned into needed glucose.
  • Overtime these organs become partially weakened.
  • Ketones that accumulate in the body over long
    periods of time can lead to serious illness and
  • Eventually ketone buildup can develop into
    ketosis and the ketone bodies will disrupt the
    bodys normal acid-base balance

Function of CHOs
  • Low glycogen stores or inadequate carbohydrates
    intake may cause cardiac disorder and angina
    (chest pain)
  • Central Nervous System (brain and spinal cord)
    has no stored supply of glucose therefore it is
    dependent on a minute-to-minute supply of glucose

Nature of Carbohydrates
  • Reaction driven by energy from the sun reacting
    with chlorophyll
  • Photosynthesis transforms solar energy into
  • H20 CO2 chlorophyll Glucose

Energy Production System
  • Digestion of CHOs is broken down into glucose
  • Absorption of glucose goes through the blood
  • Insulin allows for glucose utilization into the
  • Glucose is burned in the mitochondria making ATP
    through cellular respiration

  • Produces ATP from glucose
  • Found in all cells

Classes of CHOs
  • Carbohydrate sugar
  • Saccharide means sugar in Latin
  • Classified according to sugar units
  • Monosaccharide one sugar molecule
  • Disaccharides two sugar molecules
  • Polysaccharides chains of sugar molecules,
    usually glucose

  • Glucose- C6H12O6
  • Fructose- C6H12O6
  • Galactose- C6H12O6

  • Glucose is also called dextrose or blood sugar
  • Used directly by the cell for energy
  • Stored as glycogen in the muscles and liver
  • Converted to fat and stored for energy

  • Fructose is also called levulose or fruit sugar
  • Absorbed in the small intestine and transported
    to the liver where it is quickly metabolized and
    converts to glucose
  • Can form into fat if consumed in high-amounts
  • Often found in fruits

  • Galactose forms milk sugar called lactose
  • Large quantities of pure galactose do not exist
    in nature
  • The body converts galactose to glucose for energy

  • Combining two monosaccharide molecules forms a
  • Each disaccharide includes
  • glucose as a principle component
  • Sucrose Common table sugar (glucose fructose)
  • Lactose The sugar in milk and not found in
    plants (glucose galactose)
  • Maltose Not found in diet. An ingredient used
    during the production of alcohol. (glucose

  • Starch and fiber are two common forms of plant
  • Starch
  • - Plant starch accounts for approximately 50
    of the total carbohydrate intake of Americans
  • - The term complex carbohydratecommonly refers
    to dietary starch

  • Fiber is a polysaccharide
  • Humans lack the necessary enzymes (a protein that
    accelerates a specific chemical reaction without
    altering itself ) to digest fiber
  • No direct energy value
  • Fibers can be water-soluble gums and pectin
  • Water-insoluble cellulose, hemicellulose, and

Water Soluble vs Water Insoluble Fiber
  • Water Soluble Fiber
  • Mixes well with water
  • Slows digestion
  • Can help with weight loss
  • Helps regulate blood sugar levels and cholesterol

Water Soluble vs Water Insoluble Fiber
  • Water Insoluble Fiber
  • Is not soluble in water. No physical change when
    it enters small intestine.
  • Passes through our digestive system in close to
    its original form
  • Helps to prevent constipation, colon cancer and
    other digestive diseases

Food labels with Dietary Fiber and with
Soluble/Insoluble Fiber
Roles of Fiber
  • Retains considerable water and thus gives bulk to
    the food residues in the intestines
  • Binds or dilutes harmful chemicals
  • Shortens transit time for food residues (and
    possibly carcinogenic materials) to pass through
    the digestive tract
  • There is no RDA for soluble and insoluble fiber.
  • There is an RDA for overall fiber. It is best
    advised to get a good combination of both

Fiber Intake and Sources
  • RDA 20-40 grams daily
  • Common sources of soluble fiber
  • Barley
  • Oatmeal
  • Oatbran
  • Apples
  • Bananas
  • Blackberries
  • Oranges
  • Grapefruit
  • Broccoli
  • Brussel Sprouts
  • Carrots
  • Nectarines
  • Peaches
  • Pears
  • Plums
  • Prunes
  • Black Beans
  • Kidney Beans
  • Navy Beans
  • Black Eyed Peas
  • Lentils
  • Chickpeas

Fiber Intake and Sources
  • Common sources of insoluble fiber
  • Bell Peppers
  • Potatoes
  • Peas
  • Pineapple
  • Skins of fruits and vegetables
  • Whole-wheat and whole-grain products
  • Wheat Bran
  • Green Beans
  • Corn
  • Seeds and Nuts
  • Strawberries
  • Raisins
  • Spinach
  • Cucumbers
  • Tomatoes
  • Granola

Other Health Benefits of Fiber
  • Increases satiety (feeling full), which aids in
    obesity prevention
  • Promotes normal bowel function
  • Adds bulk to stool
  • Slows glucose absorption-reducing blood glucose
    spikes and reducing insulin secretion
  • Prevents and helps manage diverticulosis

  • Diverticulosis
  • A condition marked by small sacs or pouches
    (diverticula) in the walls of an organ such as
    the stomach or colon. These sacs can become
    inflamed and cause a condition called
    diverticulitis, which may be a risk factor for
    certain types of cancer.

Carbohydrates Stored as Glycogen
  • Glycogen is the storage polysaccharide found in
    mammalian muscle and liver
  • Glycogen is synthesized from glucose during
  • Glycogenolysis is the reconversion process it
    provides a rapid extra muscular glucose supply

Digestion of Carbohydrates
  • Mechanical Digestion Muscular contractions
    called peristalsis break food mass into smaller
  • Chemical Digestion Enzymes break down food into
    smaller particles
  • Chemical and Mechanical Digestion begins in the
  • Mastication Chewing

Digestion of Carbohydrates
  • Chewing mixes with saliva to start the breakdown
    of starch
  • Stomach mechanical digestion only, 20-30 of
    carbohydrates have been converted to maltose
  • Small Intestine Chemical digestion is completed
    here by enzymes from the pancreas and intestine

Body Needs for Carbohydrates
  • 45 -65 daily or 225-325 g based on a 2,000
    calorie/ day diet
  • 20-40 grams of fiber daily
  • Limit sugar to no more than 25 of total calories

Refined Carbohydrates
  • Refined, when referring to processed
    carbohydrates, means they have been stripped of
    their fiber and the many nutrients now known to
    be cancer-fighters, critical for heart health,
    helping to stabilize blood sugar and even enhance
    bone health.
  • Necessary nutrients like Vitamin E, magnesium,
    boron, folic acid, zinc and phytochemicals like
    lignans, phytoestrogens and phenolic acids are
    all present in these great unrefined whole grains.

Know Your Grains
  • Whole grains are defined as grains that contain
    the completed kernel-all three parts
  • 1. Bran is packed with fiber B vitamins
  • 2. Endosperm contains carbohydrates and proteins
  • 3. Germ is rich with B vitamins, minerals, and
    phytochemicals (substances in plants)
  • Refined grains have most of the bran and germ

Know Your Grains
Test Yourself
  • 1. Which breads are usually all or mostly whole
  • whole wheat (b) multi-grain (c) rye
  • (d) pumpernickel
  • 2. Which grains are whole?
  • bulgur (b) quinoa (c) couscous
  • (d) oatmeal
  • 3. Whats the most nutritious grain?
  • corn meal (b) millet (c) quinoa
  • (d) oatmeal

  • Answer a
  • Whole wheat refers to the whole complete wheat
  • In theory, multi-grain, rye and pumpernickel
    breads can be whole grain - you must check the
    labels though. If it lists one of these whole
    grains first, it usually is
  • If it says made with enriched or wheat flour,
    multi-grain flours or pumpernickel flours, then
    it is mostly refined grain

  • 2. Answers b and d
  • Quinoa and oatmeal are whole grains
  • Bulgur and couscous may also be but check for the
    whole grain wording on the label.
  • Quinoa

  • 3. Answer c
  • Quinoa has been a staple food to the natives of
    the South American Andes since 3000 BC
  • Quinoa has the highest protein content of any
  • It is one of the grains highest in calcium, iron,
    copper, magnesium, Vitamin E, phosphorus and B
  • Quinoa is great for a vegetarian diet because of
    lysine and methonine, two amino acids which are
    generously supplied by this grain and notably low
    in vegetarian diets
  • Quinoa has a delicious nutty flavor and crunchy

Top 5 Healthiest Grains
  • 1. Quinoa (pronounced keen-wah)
  • 2. Buckwheat Groats (when roasted called Kasha)
  • 3. Barley
  • 4. Millet (it is considered to be one of the
    least allergenic and most easily digestible
  • 5. Bulgur
  • Other recognized whole grains are oats and
    oatmeal, brown rice, wild rice, corn meal, wheat
    berries and whole wheat macaroni and spaghetti.

(No Transcript)
What to Look for on the Food Label
  • Choose foods that name one of the following
    whole-grain ingredients first on the labels
    ingredient list
  • brown rice, whole oats, bulgur, whole rye, graham
    flour, whole wheat, oatmeal, wild rice,
    whole-grain corn
  • Foods labeled with the words multi-grain,
    stone-ground, 100 wheat, cracked wheat,
    seven-grain, or bran are usually not
    whole-grain products.

What to Look for on the Food Label
  • Color is not an indication of a whole grain.
    Bread can be brown because of molasses or other
    added ingredients.
  • Read the ingredient list to see if it is a whole

Tips to Help You Eat Whole Grains
  • Try brown rice or whole-wheat pasta
  • Try brown rice stuffing in baked green peppers or
    tomatoes and whole-wheat macaroni in macaroni and
  • Use whole grains in mixed dishes, such as barley
    in vegetable soup or stews and bulgur wheat in
    casserole or stir-fries
  • Create a whole grain pilaf with a mixture of
    barley, wild rice, brown rice, broth and spices.
    For a special touch, stir in toasted nuts or
    chopped dried fruit.

Tips to Help You Eat Whole Grains
  • Substitute whole wheat or oat flour for up to
    half of the flour in pancake, waffle, muffin or
    other flour-based recipes. They may need a bit
    more leavening.
  • Use whole-grain bread or cracker crumbs in
  • Try rolled oats or a crushed, unsweetened whole
    grain cereal as breading for baked chicken, fish,
    veal cutlets, or eggplant parmesan.

Tips to Help You Eat Whole Grains
  • Try an unsweetened, whole grain ready-to-eat
    cereal as croutons in salad or in place of
    crackers with soup.
  • Freeze leftover cooked brown rice, bulgur, or
    barley. Heat and serve it later as a quick side

What is High Fructose Corn Syrup?
  • Experts are finding that high-fructose corn syrup
    (HFCS) is making us fat
  • High-fructose corn syrup is a highly refined,
    artificial product
  • It is created through an intricate process that
    transforms cornstarch into a thick, clear liquid
  • Experts agree that high-fructose corn syrup is
    worse than sugar

The Dangers of High Fructose Corn Syrup
  • This manufactured fructose is sweeter than sugar
    in an unhealthy way, and is digested differently
    in a bad way.
  • Research has shown that high-fructose corn syrup
    goes directly to the liver, releasing enzymes
    that instruct the body to then store fat

The Dangers of High Fructose Corn Syrup
  • This fake fructose may slow fat burning and cause
    weight gain
  • Other research indicates that it does not
    stimulate insulin production, which usually
    creates a sense of being full. People may eat
    more than they should.
  • Increases LDL's (the bad lipoprotein) leading to
    increased risk of heart disease

The Dangers of High Fructose Corn Syrup
  • Alters magnesium balance leading to increased
    risk of osteoporosis.
  • Increased risk of Type 2 Diabetes
  • It has no enzymes or vitamins thus robbing the
    body of precious micro-nutrients.
  • It interacts with birth control pills and can
    elevate insulin levels in women on the pill.
  • Accelerates aging

The Dangers of High Fructose Corn Syrup
  • It inhibits copper metabolism leading to a
    deficiency of copper, which can cause increased
    bone fragility, anemia, ischemic heart disease
    and defective connective tissue formation among

Where Do You Find High Fructose Corn Syrup?
  • High-fructose corn syrup is highly valued by food
  • It's easy to transport in tanker trucks
  • It isn't susceptible to freezer burn, as is sugar
  • It has a long shelf life and keeps foods from
    becoming dry
  • It gives bread and baked products a wonderful

Where Do You Find High Fructose Corn Syrup?
  • It's also cheaper than white sugar, partly
    because of generous federal subsidies and trade
    policies that encourage farmers to grow more
  • Fast food chains add it to their products because
    it is cheaper.
  • It is in the sauces, in the condiments, in the
    breadings, in the buns and in soft-drinks
  • It is the commercially preferred artificial
  • What's worse than sugar? Now you know.

Glycemic Food Index
  • The Glycemic Index (GI) relates to the way your
    bodys sugar levels respond to certain foods.
  • Foods are given a rating from 0 100 on the
    glycemic index with glucose in the highest
  • High Glycemic Index foods (white bread, white
    rice, potatoes) will increase the bodys sugar
    levels rapidly whereas low glycemic index foods
    (lentils, chickpeas, navy beans) will increase
    the bodys sugar levels slowly.

Glycemic Food Index
  • Foods low on the glycemic index will release
    glucose gradually into the blood stream whereas
    foods high on the glycemic index will provoke an
    immediate response in the blood sugar levels.
  • Foods that contain carbohydrates are usually high
    on the glycemic index and have the greatest
    effect on blood sugars.
  • Pasta dishes, bread and potatoes are usually high
    on the glycemic index.

Glycemic Food Index
  • If your blood sugar is low and continues to drop
    during exercise, you would prefer to eat a
    carbohydrate that will raise your blood sugar
  • On the other hand, if you would like to keep your
    blood sugar from dropping during a few hours of
    mild activity, you may prefer to eat a carb that
    has a lower glycemic index and longer action
  • If your blood sugar tends to spike after
    breakfast, you may want to select a cereal that
    has a lower glycemic index.

Glycemic Food Index
  • The composition in the carbohydrate will also
    affect how the bodys sugar levels react.
  • For example, white bread will rate high on the
    glycemic index whereas wholegrain or rye bread
    will be rate lower on the glycemic index as it
    contains more grains and contains complex

Glycemic Food Index
  • Examples of low glycemic foods are breakfast
    cereals (which are based on wheat bran, barley
    and oats), wholegrain break, fruit, lentils,
    soybeans, baked beans etc.
  • Examples of high glycemic foods are white bread,
    soft drinks, full fat ice-cream, chocolate bars

Nutrition Assignment
  • Refer to page 19 in your nutrition book and
    answer questions 1-4 in the Case Study
    Identifying Carbohydrates And Fiber
  • Refer to page 29 in your nutrition book and
    answer Critical Thinking Questions 2 and 4