dr. saada al-orf nutrition through the life cycle chs265 nutrition basics 1st lecture

DR. SAADA AL-ORF

Nutrition Through the Life Cycle CHS265

Nutrition Basics1ST Lecture

Key Nutrition Concepts

Nutrition Through the Life Cycle-ch1-© 2009 Cengage - Wadsworth

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1. Nutrition is the study of foods, their nutrients and other chemical constituents, and the effects of food constituents on health.

2. Nutrition is an interdisciplinary science.3. Nutrition recommendations for the public change as new

knowledge about nutrition and health relationships is gained4. At the core of the science of nutrition are principles that

represent basic truths and serve as the foundation of our understanding about nutrition

5. Healthy individuals require the same nutrients across the life cycle but in differing amounts.

6. Nutritional status during one stage of the life cycle influences health status during subsequent life-cycle stages.

Introduction


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Basic nutrition information related to life-cycle stages is presented as: Principles of the science of nutrition Nutrient & other constituents of food Nutritional assessment Public food & nutrition programs How to improve nutrition

Maslow’s Hierarchy of Needs


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Principles of Human Nutrition


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Nutrition Principle #1&2


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1-Food is a basic need of humans. Food security—having access at all times to sufficient

supply of safe, nutritious foods Food insecurity—limited or uncertain availability of

safe, nutritious foods

2-Foods provide energy (calories), nutrients, and other substances needed for growth & health. Calorie—a measure of the amount of energy

transferred from food to the body Nutrients—chemical substances in food that are used

by the body

Essential Nutrients


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Nutrients the body cannot manufacture are “essential” in the diet. We must consume them. They include: Carbohydrates Certain amino acids—”building blocks” of

proteins Essential fatty acids: linoleic acid and alpha-

linolenic acid Vitamins & minerals Water

Nonessential Nutrients


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Present in foods, but not required in the diet since we can make them

Examples of nonessential nutrients: cholesterol, creatine and glucose

Factors that Impact Nutrient Needs


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AgeBody sizeGenderGenetic traitsGrowth

IllnessLifestyle habitsMedicationsPregnancy and

lactation

Dietary Intake Standards


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Dietary Reference Intakes (DRIs) General term Nutrient intake standards for healthy people

Recommended Dietary Allowances (RDAs) Levels of essential nutrients Adequate for most healthy people Decrease risk of certain chronic diseases

Adequate Intakes (AIs) “Tentative” RDAs Used when scientific information is less

conclusive

Dietary Intake Standards


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Estimated Average Requirements (EARs) Estimated values to meet requirements of half of

the healthy individuals in a group EARs are used to assess adequacy of intakes of

population groupsTolerable Upper Intake Levels (ULs)

Upper limits of nutrients compatible with health These are the limits that should not be exceeded

Theoretical Framework Used in DRI


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Standards of Nutrient Intake on Nutrition Labels


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Daily Values(DVs) are standards

for daily intakes of nutrients used on nutrition label of foods.

Six Categories of Nutrients


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Carbohydrates


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Simple carbohydrates Monosaccharides Disaccharides

Complex carbohydrates Starches Glycogen Fiber

Alcohol sugars

Carbohydrates


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Recommended intake level 45-65% of calories Added sugar: 25% or less of calories 21-35 g fiber/day for females 30-38 g fiber/day for males

Food sources Widely distributed in plant foods Milk is only animal source

CHO Sources


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• Starches are most abundant in the Bread, Cereal, Rice, and Pasta group, the Vegetable group, and the plant foods found in the Meat and Poultry group

• Natural sugars occur in the Fruit group and in the Milk, Yogurt, and Cheese group

• The apex of FGP contains sugars and other sweets such as candy, gelatin, and soft drinks

Protein


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Amino acids—”building blocks” of proteins Essential—body cannot make; must be

provided in diet Nonessential—body can make

Protein quality—high-quality proteins provide all essential amino acids

Recommended intake 10-35% of calories

Food sources (refer to Ch.1)

Essential Amino Acids


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HistidineIsoleucineLeucine LysineMethioninePhenylalanineThreonine TryptophanValine

Fats (Lipids)


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Fats—a subclass of lipids Fats = solid at room

temperature Oils = liquid at room

temperatureTriglycerides—

glycerol with 3 fatty acids attached

Essential Fatty Acids


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Essential fatty acids Linoleic acid (omega-6) Alpha-linolenic acid (omega-3)

Omega-6 to omega-3 fatty acid ratio Desirable ratio is 4 or less omega-6 to 1 omega-

3 Many Americans have a 9 to 1 omega-6 to

omega-3 intake

Saturation States


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Saturated—no double bondsUnsaturated

Monounsaturated—one double bond Polyunsaturated—2 or more double bonds

Hydrogenation and Trans Fats Hydrogenation—adds hydrogen to

unsaturated fatty acids Changes structure of fatty acid from cis

structure to trans form

Cholesterol


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Cholesterol A fat-soluble, clear liquid found in animal

products A precursor of estrogen, testosterone, and

vitamin D

Recommended Intake of Fats


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Not all fats are created equal“Unhealthful” fats

Those that raise LDL-cholesterol Examples: Trans and saturated fats and

cholesterol “Healthful” fats

Those that raise HDL-cholesterol Examples: Monounsatured, polyunsaturated,

linolenic, EPA, and DHA

Recommended Intake of Fats


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20-35% of calories from fat, limiting unhealthful fats as much as possible

Linoleic acid: 17 g/day for men, 12 g/day for women

Alpha- linolenic acid: 1.6 g/day for men, 1.1 g/day for women

Sources of fats (refer to Ch.1)

Vitamins


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Water-soluble vitamins: Thiamin, riboflavin, niacin, B6, folate, B12, biotin,

pantothenic acid, C

Fat-soluble vitamins: A, D, E, K

Functions (refer to CH.1) Coenzymes Antioxidants

Vitamins


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Recommended intakes and food sources (refer to Ch.1) Deficiencies Toxicities Many vitamins have ULs

Other substances in food Phytochemicals

Minerals


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There are 15 essential minerals

Minerals


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All 15 minerals vary in: Functions Deficiencies Overdoses

Refer to Table 1.12 to read about theseFood sources are found on Table 1.13

Water


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Adults are 60-70% waterRecommended daily intakes

12-16 cups for males 11 cups for females 75% from fluids; 25% from foods

Dietary sources Best to drink water


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• Types of solutes– Electrolytes

• Sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, sulphate

• Ions dissociate to form charged particles

– Other molecules• Glucose, protein, urea, lactate, organic acids • Remain stable

Body Solutes


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Nutrition Principle #3


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Health problems related to nutrition originate within cells.

Homeostasis—constancy of internal environment.

Nutrition Principle #4


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Poor nutrition can result from both inadequate and excessive levels of nutrient intake. Prolonged inadequate intake results in obvious

deficiencies. Overdoses of nutrients (usually by supplements) result

in mild to severe alterations in functioning.

Nutrient Function and Consequences by Level of Intake


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Steps in Development of Nutrient Deficiencies and Toxicities


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Nutrient Deficiencies are Usually Multiple


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The “ripple effect”—dietary changes introduced to improve intake of one nutrient affect intake level of other nutrients

Nutrition Principle 5&6


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5-Humans have adaptive mechanisms for managing fluctuations in food intake. Nutrient storage Regulation of absorption Regulation of appetite

6-Malnutrition can result from poor diets and from disease states, genetic factors, or combinations of these causes. Primary malnutrition—dietary in origin Secondary malnutrition—precipitated by a disease

state, surgical procedure, or medication

Nutrient-Gene Interactions


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Nutrigenomics—study of nutrient-gene interactions and effects of these interactions on health (also called nutritional genomics)

Genes code for enzymes and protein synthesis which affect body functioning

Interaction of genetic and environmental factors, including nutrition

Nutrient-Gene Interactions


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• Examples of nutrient-gene interactions:

Whole oats lowers blood cholesterol in some people but not others

Green tea reduces risk of prostate cancer in some men



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7-Some groups of people are at higher risk of becoming inadequately nourished than others Pregnant/breastfeeding women, infants, children,

people who are ill, frail elderly persons

8-Poor nutrition can influence the development of certain chronic diseases Heart disease, hypertension, cancer, stroke,

osteoporosis, type 2 diabetes, obesity



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9-Adequacy and balance are key characteristics of a healthy diet Variety Nutrient density “Empty-calorie” foods There are no “good” or “bad”

foods As Hippocrates expressed it, “All things in nutriment

are good or bad relatively.”

10-Nutrient-Dense Foods—contain high amounts of nutrients to calories Empty-Calorie Foods—contain low amounts of nutrients

to calories

Nutrition Labeling


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Nutrition Facts panel Must list fat, saturated fat, trans fat, cholesterol,

sodium, total carbohydrates, fiber, sugars, protein, vitamins A and C, calcium and iron

% Daily ValuesNutrient content and health claimsIngredient label


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Nutrition Facts Panel

Ingredient Listing


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Food products must list ingredients in an “ingredient label”

Ingredients are listed by weight, starting with the greatest amount

Dietary Supplement Labeling


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“Supplement Facts” panel lists serving size, ingredients, and % DV

Nutrient content claimsHealth claims (must include disclaimer)

Other Labeling Concerns


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Enrichment and fortification Enrichment—refined grain products have thiamin,

niacin, riboflavin and iron Fortified—addition of any other nutrient

Refined flour folic acid Milk vitamin D Low-fat and skim milk vitamins A & D

Other Labeling Concerns


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Herbal remedies Considered dietary supplements Some act like drugs, have side effects Vary in their safety and effectiveness Amount taken, duration of use and user’s age, stage,

and health status impact effect on health risk

The Life-Course Approach to Nutrition and Health


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Healthy individuals require the same nutrients throughout life.

Amounts of nutrients vary based on age, growth and development.

Diets may be defined by cultures and religions.

Nutritional and Physical Activity Guides


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My Pyramid Sample Menu


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My Pyramid Sample Menu


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Mediterranean Diet Pyramid


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Types of Diets


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• Diets:– NPO– clear liquid diet– Full liquid diet– Normal Diet– Therapeutic Diet

dr. saada al-orf nutrition through the life cycle chs265 nutrition basics 1st lecture

Documents

nutrition slide

life cyclech1

nutrition principle

nutrition recommendations

introduction nutrition

life cycle stages

science of nutrition

nutrient needs nutrition