© 2012 mcgraw-hill higher education. all rights reserved. nutrition basics chapter 12

© 2012 McGraw-Hill Higher Education. All rights reserved.

Nutrition BasicsNutrition Basics

Chapter 12


Nutritional Requirements: Nutritional Requirements: Components of a Healthy Components of a Healthy DietDiet

Your body requires 45 essential nutrients:◦ Proteins, fats, carbohydrates, vitamins,

minerals, water Macronutrients Micronutrients Body obtains nutrients through process of digestion

Energy in food is expressed as kilocalories (kcalorie)

1 kcalorie = amount of heat it takes to raise the temperature of 1 liter of fluid 1 degree centigrade

2,000 calories per day meets a person needs. 1,000 calories = 1 kcalorie 3 categories supply energy

Fat = 9 calories per gram Protein = 4 calories per gram Carbohydrates = 4 calories per gram

2


Table 12.1 The Six Classes of Table 12.1 The Six Classes of Essential NutrientsEssential Nutrients

3

© 2012 McGraw-Hill Higher Education. All rights reserved. 4

Figure 12.1 The Digestive SystemFigure 12.1 The Digestive System


Proteins – Basis of Body Proteins – Basis of Body StructureStructureForm muscle, bone, blood, enzymes,

hormones, cell membranes◦Twenty common amino acids – building

blocks Nine essential amino acids Eleven nonessential amino acids

◦Complete proteins provide all essential amino acids Most animal proteins provide complete proteins Most plant proteins are incomplete

Plants, legumes, nuts Combine 2 vegetables to make up missing amino acids

◦Recommended amount 0.36 grams per pound of body weight 10-35% of total calorie intake

Average is 15-16%

5


Fats (or Lipids)Fats (or Lipids)Essential in small amountsMost concentrated source of energy (9

cals/gram)◦ Stored energy, provides insulation and support for

body organs◦ Two fats are essential components of diet

Linoleic acid Alpha-linolenic acid

◦ 10% from saturated fats◦Triglycerides - glycerol molecule with 3 fatty acid chains

Animal fats primarily made of triglyceridesUnsaturatedMonounsaturatedPolyunsaturatedSaturatedHydrogenationTrans fatty acids

6


Fats and HealthFats and HealthCholesterol

◦ Low density lipoprotein (LDL) – “bad” cholesterol◦ High density lipoprotein (HDL) – “good” cholesterol

Absorbs fat-soluble vitamins (A,D,E, K)Omega-3 fatty acids – AMDR 5-10%Omega-6 fatty acids – AMDR 0.6-1.2%Recommended intake

◦ Adults Men 17 grams per day of linoleic and 1.6 grams of alpha-linolenic Women 12 grams per day of linoleic and 1.1 grams of alpha-

linolenic◦ Only 3-4 teaspoons (15-20 grams) of vegetable oil per

day◦ AMDRs for total fat 20-35%

7


CarbohydratesCarbohydratesSupply energy for body cellsTwo groups

◦Simple carbs: one or two sugar units Fruit, sugar, honey, malt, and milk

◦Complex carbs: multiple sugar units Starches and fiber

Grains – wheat, rye, rice, oats, barley, millet Legumes – dry beans, peas, lentils Tubers – potatoes, yams

◦Digestion Mouth and small intestines Break down to glucose

8


Refined Carbohydrates Refined Carbohydrates versus Whole Grainsversus Whole GrainsRefined (processed)Unrefined (whole grains)All grains before processing

◦Inner layer: germ◦Middle layer: endosperm◦Outer layer: bran

During processing◦Germ and bran are removed, leaving

just the starchy endosperm9


Glycemic Index and Glycemic Index and Glycemic ResponseGlycemic Response

Insulin and glucose levelsQuick rise in glucose and insulin

levels = high glycemic index◦Eating high glycemic index foods

may increase appetite◦May increase risk of diabetes and

heart disease◦Unrefined grains, fruits, vegetables

and legumes – relatively low glycemic index

10


Recommended Carbohydrate Recommended Carbohydrate IntakeIntakeAverage American consumes 200-300

grams130 grams needed to meet the body’s

requirements for essential carbohydrates

Recommended: adults 45-65% of total daily calories (225-325 grams)

WHO recommends a limit of 10% of total calories from added sugars

USDA recommends about 8 teaspoons of sugar per day

11


Fiber – A Closer LookFiber – A Closer LookFood and Nutrition Board

◦ Dietary fiber: nondigestible carbohydrate that is present naturally

◦ Functional fiber: nondigestible carbohydrate that has been isolated or synthesized

◦ Total fiber is the sum of both◦ Soluble (viscous) fiber◦ Insoluble fiber

Sources◦ All plant substances

Recommended intake◦ 38 grams for adult men◦ 25 grams for adult women◦ Needs to come from foods, not supplements

12


VitaminsVitaminsOrganic (carbon-containing) substances

required in small amounts to regulate various processes within a living cell

13 vitamins:◦ 4 fat soluble: A, D, E, K◦ 9 water soluble: C and 8 B-complex vitamins (thiamin

(B1), riboflavin (B2), niacin (B3), pyridoxine (B6), folate, B-12, biotin, pantothenic acid)

Sources:◦ Human body does not manufacture most vitamins◦ Abundant in fruits, vegetables, grains

13


MineralsMineralsInorganic micronutrients (do not contain

carbon)Help to regulate body functions, aid

growth, maintain body tissues, release energy

17 essential minerals◦Major minerals: 100+ milligrams per day

Calcium, phosphorus, magnesium, sodium, potassium, chloride

◦Trace minerals: minute amounts Copper, fluoride, iodide, iron, selenium, zinc

14


WaterWaterYou are composed of about 50-60% waterCan live up to 50 days without food, but

only a few days without waterFood and fluids you consume provide

80-90% of your daily water intake;the rest is through metabolism

Food and Nutritional Board◦ Men: 3.7 total liters of water, with 3.0 liters

(13 cups) coming from beverages◦ Women: 2.7 total liters of water, with 2.2 liters

(9 cups) coming from beverages

15


Other Substances in FoodOther Substances in FoodAntioxidants

◦React with free radicals◦Vitamin C, vitamin E, selenium,

carotenoids Phytochemicals

◦Soy foods may help lower cholesterol levels

◦Cruciferous vegetables render some carcinogenic compounds harmless

◦Allyl sulfides (garlic and onions) boost the cancer-fighting immune cells

16


Nutritional Guidelines:Nutritional Guidelines:Planning Your DietPlanning Your DietHere are several tools to help you

design a healthy diet:◦ Dietary Reference Intakes◦ Dietary Guidelines for Americans◦ MyPyramid

17


Dietary Reference Intakes Dietary Reference Intakes (DRIs)(DRIs)Food and Nutrition Board set standardsRDAs (recommended daily allowance)AI (adequate intake)Include standards for both recommended

and maximum safe intakesEstablished standards for nutrient intakePrevent nutrient deficienciesPromote healthDaily Values used on food labels

◦ Based on 2,000 calorie diet

18


Dietary Guidelines for Dietary Guidelines for AmericansAmericansReduce overall caloriesEat a variety of nutrient-dense foodsLimit saturated fats to less than 7% of total

caloriesLimit cholesterol to less than 300 mg per dayChoose high-quality proteinsChoose carbohydrates wiselyEat less sodiumEat more potassiumReduce or eliminate alcoholFollow food safety guidelines

19


Figure 12.3 Nutrient Density of 12-Figure 12.3 Nutrient Density of 12-ounce Portions of Selected Beveragesounce Portions of Selected Beverages


USDA’s MyPyramidUSDA’s MyPyramidUSDA released in 2005Reminds consumers to make healthy food

choices and to be active every dayKey messages: Personalization Daily physical activity Moderation of food intake Proportionality Variety Gradual improvement

21


Figure 12.4 Figure 12.4 USDA’s MyPyramidUSDA’s MyPyramid

22


Figure 12.5 MyPyramid Figure 12.5 MyPyramid Food Intake PatternsFood Intake Patterns

23


Table 12.6 MyPyramid Daily Table 12.6 MyPyramid Daily Calorie Intake LevelsCalorie Intake Levels

24


MyPyramid: Number of MyPyramid: Number of Daily Servings and Serving Daily Servings and Serving SizesSizesGrains (6)Grains (6):: 1 slice of bread, 1 small muffin

(2.5” diameter), 1 cup ready-to-eat cereal flakes, ½ cup cooked cereal, 1 (6”) tortilla

Vegetables (5)Vegetables (5):: ½ cup cooked or raw vegetables, 1 cup raw leafy salad greens,½ cup of vegetable juice

Fruit (4)Fruit (4): : ½ cup fresh/canned/frozen fruit, ½ cup 100% fruit juice, 1 small whole fruit, ¼ cup dried fruit

25


Milk/Dairy (3)Milk/Dairy (3): : 1 cup milk or yogurt, ½ cup ricotta cheese, 1½ oz. natural cheese, 2 oz. processed cheese

Meat and Beans (5½)Meat and Beans (5½):: 1 oz. cooked lean meat/poultry/fish, ¼ cup cooked dry beans or tofu, 1 egg, 1 tablespoon peanut butter, ½ oz. nuts or seeds

Oils (6 teaspoons per day)Oils (6 teaspoons per day)Discretionary calories,Discretionary calories,

solid fats, and added sugarssolid fats, and added sugars

26

MyPyramid: Number of MyPyramid: Number of Daily Servings and Serving Daily Servings and Serving SizesSizes


The Vegetarian The Vegetarian AlternativeAlternativeReasonsTypes:

◦ Vegans◦ Lacto-vegetarians◦ Lacto-ovo-vegetarians◦ Partial vegetarians◦ Semivegetarians◦ Pescovegetarians

A food plan for vegetarians◦ Vitamin B-12◦ Vitamin D◦ Calcium◦ Iron◦ Zinc

27


Functional FoodsFunctional FoodsFoods to which health-promoting

or disease-preventing components have been added

Fortified, enriched, enhancedExamplesCalcium-fortified orange juiceMargarine enriched with sterols to

lower the risk of heart diseaseSports bars for energyVitamin B-12 enriched soy milk

28


Dietary Challenges for Dietary Challenges for Special Population GroupsSpecial Population Groups

Children and teenagersCollege studentsOlder adultsAthletesPeople with special health

concerns

29


A Personal Plan: Making A Personal Plan: Making Informed Choices About FoodInformed Choices About Food

Reading food labelsReading dietary supplement

labelsEvaluating functional foods

30


Using Food LabelsUsing Food Labels


Protecting Yourself Against Protecting Yourself Against Foodborne IllnessFoodborne Illness

Causes of foodborne illnesses:◦ Campylobacter jejuni◦ Salmonella◦ Shigella◦ Escherichia coli◦ Listeria monocytogenes◦ Staphylococcus aureus◦ Clostridium botulinum◦ Norovirus

Preventing and treating foodborne illnesses

32


Organic foods◦ Concerned about pesticides and other

environmental contaminants◦ Must meet strict USDA guidelines

Guidelines for fish consumption◦ Do not eat shark, swordfish, king mackerel,

or tilefish◦ Eat up to 12 oz. a week of a variety of fish

and shellfish that is lower in mercury◦ Limit albacore tuna to 6 oz. per week◦ Check advisories about the safety of

recreationally caught fish

Environmental Environmental Contaminants and Organic Contaminants and Organic FoodsFoods

33


Some 2,800 substances are added to foods to maintain or improve nutritional quality, freshness, to help in processing or preparation, or to alter taste or appearance

Most common: sugar, salt, corn syrup, citric acid, baking soda, vegetable colors, mustard, pepper

Potential health concerns: Nitrates and nitrites BHA and BHT Sulfites Monosodium glutamate (MSG)

Additives in FoodAdditives in Food

34


Used to produce specific desired traits in plants, animals, or microorganisms

Food irradiation Kills potentially harmful pathogensGenetically modified foods (GM) Alters characteristics of a plant, animal, or

microorganism through gene manipulationAnimal cloning FDA deems safe for human consumption, but

probably will be used as breeding stockLabeling of GM foods FDA does not require special labeling for GM foods

Food BiotechnologyFood Biotechnology

35


Food Allergies and Food Food Allergies and Food IntolerancesIntolerancesFood allergies

◦Reaction of the body’s immune system◦Affect 1.5% of the adult population◦Affect up to 6% of infants◦90% of food allergies

Cow’s milk, eggs, peanuts, tree nuts, soy, wheat, fish, shellfish

Food intolerances◦Problem lies with metabolism rather

than with the immune system

36


Nutrition BasicsNutrition Basics

Chapter 12

© 2012 mcgraw-hill higher education. all rights reserved. nutrition basics chapter 12

Documents