Nutrition

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Nutrition

• Chapter 8

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Nutritional Requirements Components of a Healthy
Diet

• Essential nutrients substances the body must
  get from food because it cannot manufacture them
  at all or fast enough to meet its needs
• Proteins
• Carbohydrates
• Fats
• Vitamins
• Minerals
• Water

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Energy from Food

• Three classes of essential nutrients supply
  energy. Which ones?
• Kilocalorie a measure of energy content in
  food the amount of heat it takes to raise the
  temperature of 1 liter of water 1C commonly
  referred to as calorie

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Sources of Energy in the Diet
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ProteinsThe Basis of Body Structure

• Protein a compound made of amino acids that
  contains carbon, hydrogen, oxygen, and nitrogen
• Of twenty common amino acids in foods, nine are
  essential
• Proteins form key parts of the bodys main
  structural componentsmuscles and bonesand of
  blood, enzymes, cell membranes, and some hormones

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FatsEssential in Small Amounts

• Fats supply energy, insulate the body, support
  and cushion organs, absorb fat-soluble vitamins,
  add flavor and texture to foods
• Essential fats are key regulators of body process
  such as the maintenance of blood pressure and the
  progress of a healthy pregnancy

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Types and Sources of Fats

• Saturated fat a fat with no carbon-carbon
  double bonds usually solid at room temperature
• Found primarily in animal foods and palm and
  coconut oils
• Monounsaturated fat a fat with one
  carbon-carbon double bond usually liquid at room
  temperature
• Found in certain vegetables, nuts, and vegetable
  oils
• Polyunsaturated fat a fat with two or more
  carbon-carbon double bonds usually liquid at
  room temperature
• Found in certain vegetables, nuts, and vegetable
  oils and in fatty fish

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Fats and Health

• Fats also affect triglyceride levels,
  inflammation, heart rhythm, blood pressure, and
  cancer risk
• Best choices monounsaturated fats and
  polyunsaturated omega-3 fats
• Limit intake of saturated and trans fats

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Fats and Health

• Fats affect blood cholesterol levels
• Low-density lipoprotein (LDL) bad cholesterol
• High-density lipoprotein (HDL) good
  cholesterol
• Saturated and trans fats raise levels of LDL
  trans fats also lower levels of HDL
• Unsaturated fats lower levels of LDL

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CarbohydratesAn Ideal Source of Energy

• The primary function of dietary carbohydrate is
  to supply energy to body cells.
• Some cells, such as those in the brain, nervous
  system, and blood, use only carbohydrates for
  fuel
• During high-intensity exercise, muscles get most
  of their energy from carbohydrates
• During digestion, carbohydrates are broken into
  single sugar molecules such as glucose for
  absorption the liver and muscles take up glucose
  and store it in the form of glycogen

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Simple and Complex Carbohydrates

• Simple carbohydrates contain one or two sugar
  units in each molecule
• Found naturally in fruits and milk and added to
  many other foods
• Include sucrose, fructose, maltose, and lactose
• Complex carbohydrates consist of chains of many
  sugar molecules
• Found in plants, especially grains, legumes, and
  tubers
• Include starches and most types of dietary fiber

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Whole Grains

• Before they are processed, all grains are whole
  grains consisting of an inner layer of germ, a
  middle layer called the endosperm, and an outer
  layer of bran
• During processing, the germ and bran are often
  removed, leaving just the starchy endosperm
• Refined carbohydrates usually retain all the
  calories of a whole grain but lose many of the
  nutrients

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Refined Carbohydrates Versus Whole Grains

• Whole grains are higher than refined
  carbohydrates in fiber, vitamins, minerals, and
  other beneficial compounds
• Whole grains take longer to digest
• Make people feel full sooner
• Cause a slower rise in glucose levels
• Choose foods that have a whole grain as the first
  item on the ingredient list on the food label
• Whole wheat, whole rye, whole oats, oatmeal,
  whole-grain corn, brown rice, popcorn, barley,
  etc.

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Reading a Food Label
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1. Serving Size

• The first place to start when you look at the
  Nutrition Facts label
• Serving sizes are standardized to make it easier
  to compare similar foods
• They are provided in familiar units, such as cups
  or pieces, followed by the metric amount, e.g.,
  the number of grams.
• The size of the serving on the food package
  influences the number of calories and all the
  nutrient amounts listed on the top part of the
  label.
• Pay attention to the serving size, especially how
  many servings there are in the food package. Then
  ask yourself, "How many servings am I consuming"?
  (e.g., 1/2 serving, 1 serving, or more)
• In the sample label, one serving of macaroni and
  cheese equals one cup. If you ate the whole
  package, you would eat two cups. That doubles the
  calories and other nutrient numbers, including
  the Daily Values as shown in the sample label.

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2. Calories (and calories from fat)

• Calories provide a measure of energy
• The calorie section of the label can help you
  manage your weight.
• Only about 30 of your calories should come from
  fat.
• Remember the number of servings you consume
  determines the number of calories you actually
  eat (your portion amount).
• A guide 40 Calories is low, 100 Calories is
  moderate and 400 Calories or more is high

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3. The nutrients
Limit These Nutrients
Get Enough of These
Eating too much fat, saturated fat, trans fat,
cholesterol, or sodium may increase your risk of
certain chronic diseases, like heart disease,
some cancers, or high blood pressure.
Eating enough of these nutrients can improve your
health and help reduce the risk of some diseases
and conditions.
Remember You can use the Nutrition Facts label
not only to help limit those nutrients you want
to cut back on but also to increase those
nutrients you need to consume in greater amounts.
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5. Understanding the Footnote on the Bottom of
the Nutrition Facts Label
This statement must be on all food labels.
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6. The Percent Daily Value (DV)
5DV or less is low and 20DV or more is high
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Plain vs Fruit Yogurt
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Glycemic Index

• Consumption of carbohydrates causes insulin and
  glucose levels in the blood to rise and fall
• Glycemic index a measure of how the ingestion
  of a particular food affects blood glucose levels
• Foods with a high glycemic index cause quick and
  dramatic changes in glucose levels
• Diets rich in high glycemic index foods are
  linked to increased risk of diabetes and heart
  disease
• High glycemic Bread, Pasta, Rice, Baked goods
• Low glycemic Fruits, Vegetables, Whole grains

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Acceptable Macronutrient Distribution Ranges
Summary

• Protein 1035 of total daily calories
• Fat 2035 of total daily calories
• Carbohydrate 4565 of total daily calories

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FiberA Closer Look

• Dietary fiber nondigestible carbohydrates and
  lignin that are present naturally in plants
• Functional fiber nondigestible carbohydrates
  isolated from natural sources or synthesized in a
  lab and added to a food or supplement
• Total fiber dietary fiber functional fiber

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Types of Fiber

• Soluble (viscous) fiber fiber that dissolves in
  water or is broken down by bacteria in the large
  intestine
• Slows the bodys absorption of glucose
• Binds cholesterol-containing compounds
• Insoluble fiber fiber that doesnt dissolve in
  water
• Makes feces bulkier and softer
• Helps prevent constipation, hemorrhoids, and
  diverticulitis

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Sources of Fiber

• All plant foods contain fiber, but processing can
  remove it
• Good sources of fiber
• Fruits (especially whole, unpeeled fruits)
• Vegetables
• Legumes
• Oats (especially oat bran)
• Whole grains and wheat bran
• Psyllium (found in some cereals and laxatives)

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VitaminsOrganic Micronutrients

• Vitamins organic (carbon-containing) substances
  needed in small amounts to help promote and
  regulate chemical reactions and processes in body
  cells.
• Four vitamins are fat-soluble (A, D, E, and K)
• Nine vitamins are water-soluble (C and the eight
  B-complex vitamins thiamin, riboflavin, niacin,
  vitamin B-6, folate, vitamin B-12, biotin, and
  pantothenic acid)

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Vitamins

• Vitamins are abundant in fruits, vegetables, and
  grains they are also added to some processed
  foods
• If you consume too much or too little of a
  particular vitamin, characteristic symptoms of
  excess or deficiency can develop
• Vitamins commonly lacking in the American diet
• Vitamin A
• Vitamin C
• Vitamin B-6
• Vitamin E

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MineralsInorganic Micronutrients

• Minerals inorganic (non-carbon-containing)
  compounds needed in small amounts for regulation,
  growth, and maintenance of body tissues and
  functions
• There are about 17 essential minerals
• Major minerals (those that the body needs in
  amounts exceeding 100 mg per day) include
  calcium, phosphorus, magnesium, sodium,
  potassium, and chloride
• Essential trace minerals include copper,
  fluoride, iodide, iron, selenium, and zinc

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Minerals

• If you consume too much or too little of a
  particular mineral, characteristic symptoms of
  excess or deficiency can develop
• Minerals commonly lacking in the American diet
• Iron low intake can cause anemia
• Calcium low intake linked to osteoporosis
• Potassium low intake linked to elevated blood
  pressure and bone mineral loss

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WaterA Vital Component

• Human body is composed of about 60 water you
  can live only a few days without water
• Foods and fluids you consume provide 8090 of
  your daily water intake
• Adequate intake to maintain hydration
• Women need to drink about 9 cups of fluid per day
• Men need to drink about 13 cups of fluid per day
• Drink in response to thirst consume additional
  fluids for heavy exercise

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Other Substances in Food Antioxidants

• Antioxidant a substance that protects against
  the breakdown of body constituents by free
  radicals actions include binding oxygen,
  donating electrons to free radicals, and
  repairing damage to molecules
• Free radical a chemically unstable,
  electron-seeking compound that can damage cell
  membranes and mutate genes in its search for
  electrons
• Many fruits and vegetables are rich in
  antioxidants such as vitamin C, vitamin E,
  selenium, and carotenoids

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Should You Take Supplements?

• The Food and Nutrition Board recommends
  supplements only for certain groups
• Folic acid for women capable of becoming pregnant
  (400 µg/day)
• Vitamin B-12 for people over age 50 (2.4 mg/day)
• Other possible situations for supplements
• Vitamin C for smokers
• Iron for menstruating women
• Vitamin K for newborns
• People with certain special health concerns

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Leading Sources of Calories in the American Diet

• 1. Regular soft drinks (7.1 of total calories)
• 2. Cake, sweet rolls, doughnuts, pastries
  (3.6)
• 3. Hamburgers, cheeseburgers, meat loaf (3.1)
• 4. Pizza (3.1)
• 5. Potato chips, corn chips, popcorn (2.9)
• 6. Rice (2.7)
• 7. Rolls, buns, English muffins, bagels (2.7)
• 8. Cheese or cheese spread (2.6)
• 9. Beer (2.6)
• 10. French fries, fried potatoes (2.2)
• Source Block, G. 2004. Foods contributing to
  energy intake in the U.S. Data from NHANES III
  and NHANES 19992000. Journal of Food Composition
  and Analysis 17 439447.

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Alternative Food Plans Healthy Eating Pyramid
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Alternative Food Plans Canadas Food Guide
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Dietary Challenges for Special Population Groups
Athletes

• Energy intakeadequate calories and nutrients
• Carbohydrates60 to 65 of total daily calories
  for most athletes, up to 70 for endurance
  athletes
• Protein (grams per day per kilogram of body
  weight)
• Endurance athletes 1.2 to 1.4 grams
• Heavy strength training 1.6 to 1.7 grams
• Fluidsremain hydrated
• 14 to 22 oz of fluid two hours before strenuous
  event
• 6 to 12 oz every 1520 minutes during exercise
• Replace fluids after event (check body weight)

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A Personal Plan Applying Nutritional Principles

• Assess your current diet
• Set goals for change
• Try additions and substitutions to bring your
  current diet closer to your goals
• Plan ahead for challenging situations
• Make smart choices about nutrition! See the
  following recommendations.

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What Type of Food Should People Choose?

• The type of food that people eat is just as
  important as the amount.
• Eat at least one dark green and one orange
  vegetable each day.
• Have vegetables and fruit more often than juice.
• Make at least half of your grain products whole
  grain each day.
• Drink skim, 1 or 2 milk each day.
• Have meat alternatives such as beans, lentils and
  tofu often.
• Eat at least two Food Guide Servings of fish each
  week.
• Include a small amount of unsaturated fat each
  day.
• Satisfy your thirst with water.

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Lowering fat

• It is best to reduce the total amount of fat in
  your diet and reduce the amount of saturated and
  trans fats you consume.
• Higher fat foods are often higher in saturated
  and trans fats. These kinds of fats put people at
  higher risk of cardiovascular disease.
• Saturated fats are found in fatty meats, higher
  fat milk products, butter, lard, shortening, hard
  margarines and tropical oils such as coconut and
  palm oil.
• Trans fats are found in many deep-fried foods,
  fast foods, salty snacks and baked goods made
  with shortening or partially hydrogenated
  vegetable oils.

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Lowering salt

• Most people get more sodium than they need,
  especially if they eat packaged, processed foods
  and meals made outside of the home.
• Some of the foods that can be high in sodium
  include snack foods, such as crackers, nachos,
  potato chips and pretzels, cheese, gravies and
  sauces, processed luncheon meats, canned or dried
  soups and frozen meals.
• People should compare the Nutrition Facts table
  on similar products and choose the one that has a
  lower number for the Daily Value of sodium.

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Lowering sugar

• Baked goods and desserts, such as cakes, candies,
  chocolate, cookies, doughnuts, ice cream,
  muffins, pastries and pies, and sweetened cold
  and hot beverages, such as energy drinks, fruit
  flavoured drinks, soft drinks, sports drinks, hot
  chocolate and specialty coffees, can be high in
  sugar and should be limited.
• When cooking, try roasting, grilling, baking,
  stir-frying, steaming or poaching - all methods
  that require little or no added fat. For tips on
  preparing foods with little or no added fat,
  sugar or salt.

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Remember

• Think before you eat!
• Move! (energy balance)
• Make a plan for yourself it is your body, your
  health!
• Enjoy your life but do it in a smart way!