Chapt01 Lecture Nutrition
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Transcript of Chapt01 Lecture Nutrition
Chapter 1: What you eat and why
Chapter 1: What Chapter 1: What You Eat and Why?You Eat and Why?
Chapter 1: What you eat and whyFactors Affecting Food ChoicesFactors Affecting Food Choices
Social needs
Psychologicalneeds
Food availability
Food marketing
Health and nutritionconcerns, knowledge,
and beliefs
Lifestyle
Routinesand
habits
Education,occupation,and income
Food cost
Food customsand
culture
Social networkof family
and friends
Food flavor, texture, and appearance
preferences
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Chapter 1: What you eat and why
NNutrition isutrition is
““the science of food, the nutrients the science of food, the nutrients and the substances therein, their and the substances therein, their action, interaction, and balance in action, interaction, and balance in relation to health and disease, relation to health and disease, and the process by which the and the process by which the organism ingests, absorbs, organism ingests, absorbs, transport, utilizes, and excretes transport, utilizes, and excretes food substances”----food substances”----The Council on Food The Council on Food and Nutrition of the American Medical Associationand Nutrition of the American Medical Association
Chapter 1: What you eat and why
Scientific MethodScientific Method
the careful noting and recording of natural phenomena
a procedure designed to test an idea
a tentative explanation of a single or small number of natural phenomena
a general explanation of natural phenomena
a generally observed natural phenomenon
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Chapter 1: What you eat and why
Gathering Empirical Gathering Empirical KnowledgeKnowledge──ObservationObservation
Some observations are simple Some observations are simple descriptions about the descriptions about the characteristics or behavior of characteristics or behavior of naturenature──qualitativequalitative..– ““The soda pop is a liquid with a The soda pop is a liquid with a
brown color and a sweet taste. brown color and a sweet taste. Bubbles are seen floating up Bubbles are seen floating up through it.through it.””
Some observations compare a Some observations compare a characteristic to a standard characteristic to a standard numerical scalenumerical scale──quantitativequantitative..– ““A 240-mL serving of soda pop A 240-mL serving of soda pop
contains 27 g of sugar.contains 27 g of sugar.””5
Chapter 1: What you eat and why
From Observation to UnderstandingFrom Observation to Understanding
hypothesishypothesis──a tentative a tentative interpretation or explanation for interpretation or explanation for an observationan observation– ““The sweet taste of soda pop is due The sweet taste of soda pop is due
to the presence of sugar.to the presence of sugar.”” A good hypothesis is one that can A good hypothesis is one that can
be tested to be proved wrong!be tested to be proved wrong!– falsifiablefalsifiable– One test may invalidate your One test may invalidate your
hypothesis.hypothesis.6
Chapter 1: What you eat and why
Testing IdeasTesting Ideas• Ideas in science are tested with Ideas in science are tested with
experimentsexperiments..• An experiment is a set of procedures An experiment is a set of procedures
that are designed to test whether an that are designed to test whether an idea about nature is valid.idea about nature is valid.
• The experiment generates The experiment generates observations that will either validate observations that will either validate or invalidate the idea.or invalidate the idea.
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Chapter 1: What you eat and why
From Specific to General From Specific to General ObservationsObservations
• A A scientific lawscientific law is a summary of is a summary of observations that combines all observations that combines all past observations into one past observations into one general statement.general statement.
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• Allows you to predict future observationsSo you can test the law with
experiments.
Chapter 1: What you eat and why
From Specific to General From Specific to General UnderstandingUnderstanding
• A A hypothesishypothesis is a potential is a potential explanation for a single or small explanation for a single or small number of observations.number of observations.
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• A theory is a general explanation for the manifestation and behavior of all nature.modelspinnacle of scientific knowledgevalidated or invalidated by
experiment and observation
Chapter 1: What you eat and why
• • Make an observationMake an observation– Form a hypothesis via Form a hypothesis via inductive inductive
reasoningreasoning– Conduct an experiment, collect Conduct an experiment, collect
data, make further observationsdata, make further observations– Reach a conclusionReach a conclusion– Formulate a theory Formulate a theory – ModelsModels– Repeat/statistical significanceRepeat/statistical significance– New questionsNew questions
Chapter 1: What you eat and why
Experiments performed in science have specific Experiments performed in science have specific elementselements
The experimental design is the well-conceived plan for a The experimental design is the well-conceived plan for a specific experiment.specific experiment.
• • ExperimentsExperiments typically have two groups.typically have two groups.–– Experimental group:Experimental group: the group manipulated during the experiment the group manipulated during the experiment–– Control groupControl group: the reference group, left unmanipulated: the reference group, left unmanipulated
Experiments collect data.Experiments collect data.– Experimental variable Experimental variable (Independent): factor of the experiment being (Independent): factor of the experiment being
tested.tested.– Response Variable Response Variable (Dependent): Result or change that occurs due to (Dependent): Result or change that occurs due to
the experimental variablethe experimental variable
Chapter 1: What you eat and why
Nutrients Come from FoodNutrients Come from Food Provide energyProvide energy Provide building blocksProvide building blocks Vital for growth and Vital for growth and
maintenancemaintenance EssentialEssential
Chapter 1: What you eat and why
Essential NutrientEssential NutrientOmission leads to declineOmission leads to declineRegain normal function when Regain normal function when
restored to the dietrestored to the dietHas specific biological Has specific biological
functionfunction
Chapter 1: What you eat and why
Why study Why study nutrition?nutrition?
Chapter 1: What you eat and why
Nutrition and HealthNutrition and Health
Poor diet and sedentary lifestyle are Poor diet and sedentary lifestyle are risk factors for chronic diseases:risk factors for chronic diseases:– Disease of the heart (29% of all deaths)Disease of the heart (29% of all deaths)– Cancer (22%)Cancer (22%)– Cerebrovascular disease (~7%)Cerebrovascular disease (~7%)– Diabetes (3%)Diabetes (3%)– Accounts for ~2/3 of all deathsAccounts for ~2/3 of all deaths
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Maintain optimal healthMaintain optimal health ““Affliction of Affluence”Affliction of Affluence” We are living longerWe are living longer
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The Six Classes of The Six Classes of NutrientsNutrients
CarbohydratesCarbohydrates Lipids Lipids ProteinsProteins VitaminsVitamins MineralsMinerals WaterWater
Chapter 1: What you eat and why
Nutrient Functional Nutrient Functional CategoriesCategories
Provide caloriesProvide calories For growth, development, and For growth, development, and
maintenancemaintenance Regulate body processesRegulate body processes
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CarbohydratesCarbohydrates Composed of carbon, hydrogen, oxygenComposed of carbon, hydrogen, oxygen Major source of fuel Major source of fuel Monosaccharide (glucose) Monosaccharide (glucose) Simple and complex formsSimple and complex forms
Chapter 1: What you eat and why
CarbohydratesCarbohydrates
Chapter 1: What you eat and why
CarbohydratesCarbohydrates Dietary fiberDietary fiber Energy yielding (~4 kcal /gm)Energy yielding (~4 kcal /gm)
Chapter 1: What you eat and why
LipidsLipids Composed of Composed of
carbon, carbon, hydrogen, fewer hydrogen, fewer oxygenoxygen
Triglycerides Triglycerides – Fats and oilsFats and oils
Chapter 1: What you eat and why
LipidsLipids Unsaturated Fatty AcidsUnsaturated Fatty Acids Saturated Fatty AcidsSaturated Fatty Acids
Chapter 1: What you eat and why
LipidsLipids Essential Fatty AcidsEssential Fatty Acids Energy yielding fats and oils (~9 kcal /gm)Energy yielding fats and oils (~9 kcal /gm) CholesterolCholesterol PhospholipidsPhospholipids
Chapter 1: What you eat and why
ProteinsProteins Composed of carbon, hydrogen, oxygen, nitrogenComposed of carbon, hydrogen, oxygen, nitrogen Structural materialStructural material (9) Essential amino acids (9) Essential amino acids (11) Nonessential amino acids(11) Nonessential amino acids Energy yielding (~4 kcal /gm)Energy yielding (~4 kcal /gm) Excess protein Excess protein intakeintake
Chapter 1: What you eat and why
ProteinsProteinsChemical structure
Globularstructure
Chapter 1: What you eat and why
VitaminsVitamins Composed of various elementsComposed of various elements Enable chemical reactionsEnable chemical reactions Fat solubleFat soluble Water solubleWater soluble Yield no energyYield no energy
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MineralsMinerals Inorganic substancesInorganic substances Function in cellular processes, nervous Function in cellular processes, nervous
system, water balance, structural system, water balance, structural systemssystems
Not destroyed during cookingNot destroyed during cooking Trace mineralsTrace minerals Major mineralsMajor minerals Electrolytes Electrolytes Yield no energyYield no energy
Chapter 1: What you eat and why
WaterWater Composed of hydrogen, oxygenComposed of hydrogen, oxygen Majority of our body weightMajority of our body weight Found in foodsFound in foods Yields no energyYields no energy Functions:Functions:
– Solvent, lubricant, medium for transport, Solvent, lubricant, medium for transport, chemical processes, and temperature regulatorchemical processes, and temperature regulator
Chapter 1: What you eat and why
Chapter 1: What you eat and why
PhytochemicalsPhytochemicals
A chemical found in plantsA chemical found in plants
– Not considered essential nutrientsNot considered essential nutrients– Provide significant health benefitsProvide significant health benefits– Found in fruits and vegetablesFound in fruits and vegetables
Chapter 1: What you eat and why
Chapter 1: What you eat and why
CompositionComposition
Chapter 1: What you eat and why
Transformation of EnergyTransformation of EnergyCarbohydrate Protein Fat
(4 kcal/gm 4 kcal/gm 9 kcal/gm
ENERGY SOURCES
Build new compounds Muscular movement
Nerve transmission Ion balance
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What is a Calorie?What is a Calorie? Measurement of energyMeasurement of energy ““The amount of heat it takes to The amount of heat it takes to
raise the temperature of 1 gram raise the temperature of 1 gram of water by 1 degree Celsius”of water by 1 degree Celsius”
1,000 calories = 1 kcal = 1(food) 1,000 calories = 1 kcal = 1(food) CalorieCalorie
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Calorie SourcesCalorie Sources
CARBOHYDRATESCARBOHYDRATES 4kcal/g 4kcal/gPROTEINPROTEIN 4kcal/g4kcal/gFATFAT 9kcal/g9kcal/gALCOHOLALCOHOL 7kcal/g7kcal/g
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Sample Calculation of a Nutrition LabelSample Calculation of a Nutrition Label
Per serving Per serving – Carbohydrate: 15g x 4 kcal/g = Carbohydrate: 15g x 4 kcal/g = 60 kcal60 kcal– PRO: 3g x 4 kcal/g = PRO: 3g x 4 kcal/g = 12 kcal12 kcal– FAT: 1g x 9 kcal/g = FAT: 1g x 9 kcal/g = 9 kcal 9 kcal– TOTAL: 81 kcal, rounded down toTOTAL: 81 kcal, rounded down to 8080
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Calculating PercentagesCalculating Percentages
6% of 45 0.06 X 45= 2.76% of 45 0.06 X 45= 2.7 3 is what percent of 993 is what percent of 99
3/99=3.03%3/99=3.03%
Chapter 1: What you eat and why
Contribution to Total kcalContribution to Total kcal One day’s intake (1980 kcal)One day’s intake (1980 kcal) 290 gm of carbohydrate (x 4 kcal/gm)290 gm of carbohydrate (x 4 kcal/gm) 60 gm of fat (x 9 kcal/gm)60 gm of fat (x 9 kcal/gm) 70 gm of protein (x 4 kcal/gm)70 gm of protein (x 4 kcal/gm) % of kcal as carbohydrate = (290 x 4)/1980 = % of kcal as carbohydrate = (290 x 4)/1980 =
0.59 or 59%0.59 or 59% % of kcal as Fat= (60 x 9)/1980 = 0.27 or % of kcal as Fat= (60 x 9)/1980 = 0.27 or
27%27% % of kcal as PRO= (70 x 4)/1980 = 0.14 or % of kcal as PRO= (70 x 4)/1980 = 0.14 or
14%14%
Chapter 1: What you eat and why
The Typical American DietThe Typical American Diet 16% of kcal as proteins16% of kcal as proteins
– ~66% from animal sources~66% from animal sources– 10-35% advised10-35% advised
50% of kcal as carbohydrate50% of kcal as carbohydrate– ~50% from simple sugars~50% from simple sugars– 45-65% advised45-65% advised
33% of kcal as fat33% of kcal as fat– ~60 % from animal fats~60 % from animal fats– 20-35% advised20-35% advised
Chapter 1: What you eat and why
Assessing Our DietsAssessing Our Diets
National Health and Nutrition National Health and Nutrition Examination Survey (NHANES) [US Examination Survey (NHANES) [US Dept. of Health & Human Dept. of Health & Human Services]Services]
Chapter 1: What you eat and why
Improving Our DietsImproving Our Diets Monitor energy intakeMonitor energy intake Salt (sodium) in moderationSalt (sodium) in moderation Alcohol in moderationAlcohol in moderation Fat in moderationFat in moderation Adequate fluidsAdequate fluids Eat 5-A-DayEat 5-A-Day Use supplements wisely, if at allUse supplements wisely, if at all Mealtime is a social timeMealtime is a social time
Chapter 1: What you eat and why
Healthy People 2010Healthy People 2010www.health.gov/healthypeople
Promote healthy lifestyle Promote healthy lifestyle Reduce preventable deaths and Reduce preventable deaths and
diseasesdiseases Reduce obesity in adults and childrenReduce obesity in adults and children Increase intake of fruits, vegetables, Increase intake of fruits, vegetables,
and whole grain productsand whole grain products Lower intake of fat, saturated fats, Lower intake of fat, saturated fats,
and sodiumand sodium Increase intake of calcium and ironIncrease intake of calcium and iron
Chapter 1: What you eat and why
What can you gain?What can you gain?
Chapter 1: What you eat and why
Chapter 1: What you eat and why
Why Am I So Hungry?Why Am I So Hungry?
HungerHunger– Physical biological drivePhysical biological drive
AppetiteAppetite– Psychological drive Psychological drive
Chapter 1: What you eat and why
SatietySatiety
Regulated by the Regulated by the hypothalamushypothalamus
Feeding centerFeeding center Satiety centerSatiety center Meal size and Meal size and
compositioncomposition Macronutrients in Macronutrients in
the bloodthe blood HormonesHormones
Chapter 1: What you eat and why
Chapter 1: What you eat and why
Eating Well in Eating Well in CollegeCollege
Freshman FifteenFreshman Fifteen– Stressful situationsStressful situations– University environmentUniversity environment– Peer pressurePeer pressure– AlcoholAlcohol– Lack of ExerciseLack of Exercise
Chapter 1: What you eat and why
Weight control and Weight control and College lifeCollege life
Eat breakfastEat breakfast Plan ahead balanced mealsPlan ahead balanced meals WaterWater Low-calorie, nutritious snacksLow-calorie, nutritious snacks Eat and work out with friendsEat and work out with friends
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Other factors that affect Other factors that affect college studentscollege students
Alcohol and binge drinkingAlcohol and binge drinking Eating disordersEating disorders Vegetarian lifestyleVegetarian lifestyle