OVERVIEW OF NUTRITION

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CHAPTER 1

• OVERVIEW OF NUTRITION

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Food choices

• Good ones contribute to good health
• Bad ones contribute to bad health

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Reasons behind food choices

• Personal preferences
• Habit
• Ethnic heritage and tradition
• Social interaction
• Availability, convenience, economy
• Positive and negative associations
• Emotional comfort
• Body weight and image
• Nutritional and health benefits

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Functional foods

• Have health benefits beyond nutrient content
• Whole foods
• e.g., tomatoes
• Modified foods
• Lowered fat content
• Added nutrients
• Added phytonutrients

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Why eat?

• Nutrients-chemicals for structures, regulation,
  and energy (the capacity to do work) needed for
  growth, maintenance and renewal
• Digestive track lining is replaced every 3-5 days
• Skin is replaced every 7 years

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Food composition

• Water
• Fat (Lipids)
• Protein
• Carbohydrate
• Vitamins
• Minerals

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Body composition

• 60 water
• 21 fat
• Protein
• Carbohydrate
• Vitamins
• Minerals

You are what you eat!
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Chemical composition of nutrients

• Inorganic
• MineralsSimple elements and ions
• Water
• Organic compounds
• Carbohydrates
• Lipids
• Proteins
• vitamins

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Essential nutrients

• 40 nutrients that must be obtained from directly
  from food

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Energy yielding nutrients
Non-energy yielding nutrients

• Macronutients
• Carbohydrate
• Fat
• Protein

• Micronutrients
• Vitamins
• Minerals
• Water

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What about alcohol?

• Not considered a nutrient because it interferes
  with body chemistry
• Does yield energy
• 7C/gram

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Measure of energy

• Kilocalorie amount of energy needed to raise 1
  Kg(liter) of water 10 C
• The nutritional calorie is understood to be the
  Kilocalorie, C, as opposed to a calorie c,
  which raises one g of water 10 C.

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Energy density

• Measure of energy relative to the amount of food
• Expressed in C/gram

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Kcalorie values

• 4 Kcal/g
• Carbohydrate
• protein
• 7Kcal/g
• alcohol
• 9Kcal/g
• fat

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Metric system

• See your p. 8 of your book for units and for
  approximations with the English system

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Vitamins

• 13 complex, sensitive organic molecules
• Do not provide energy
• Are needed for chemical reactions in body

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Minerals

• 16 are needed by humans
• Simple inorganic
• Do not yield energy
• Found in dissolved in blood
• Found in hard tissue- bone and teeth

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Water

• Inorganic
• Does not yield energy
• Necessary for many metabolic reactions and
  transportation of substances.
• Major constituent of all cells

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Science of nutrition

• Scientific method
• Statistical analysis
• Cautious conclusions
• Publishing research
• Peer review

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Scientific method

• Observation and question
• Hypothesis and prediction
• Experiment
• Results and interpretation
• Publication
• Reiteration
• Theory Hypothesis always supported
• New observations and questions hypothesis not
  supported

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Dietary Reference Intakes

• Standard for energy and nutrient amounts based on
  scientific data

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What is a dietary Requirement?

• The lowest continuing intake of a nutrient that
  will maintain a specified criterion of adequacy

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Estimated average requirement (EAR)

• The average daily amount of a nutrient that will
  maintain a specific biochemical or physiological
  function in half the healthy people of a given
  age and gender group.

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Recommended daily allowance (RDA)

• Average daily amount of a nutrient considered
  adequate to meet the known nutrient needs of
  practically all healthy people a goal for
  dietary intake by individuals

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Adequate intakes (AI)

• The average daily amount of a nutrient that
  appears sufficient to maintain a specific
  criterion
• A value used as a guide for a specific nutrient
  intake when an RDA cannot be determined.

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Tolerable upper level (UL)

• Maximum daily amount of a nutrient that appears
  safe for most healthy people and beyond which
  there is an increased risk for adverse health
  effects

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Estimated energy requirement (EER)

• Average daily energy intake that maintains good
  energy balance and good health in a person for a
  given age, gender, weight, height, and level of
  physical activity

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Acceptable macronutient distribution ranges (AMDR)

• Ranges of intakes for energy nutrients that
  provide adequate energy and nutrients and reduce
  risk of chronic diseases.
• 45-65 Kcal from carbohydrate
• 20-35 Kcal from fat
• 10-35 Kcal from protein

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Using nutrient recommedations

• Estimates are for healthy people
• Recommendations are not minimal
• Most nutrient goals are intended to be met
  through food variety
• Recommendations are average daily values
• Each of the DRI categories has its own
  usefulness.

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Nutritional assessments

• Historical
• individuals and family health status,
  socioeconomic status, drug use, diet ( using
  DRIs)
• Anthropomorphic data
• Height and weight
• Physical exam
• Hair, eyes, skin, nails, etc
• Lab tests
• Analysis of blood and urine for deficiencies,
  imbalances, toxicity

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Nutrient deficiency

• Primary inadequate diet
• Secondary caused by problem in body
• ASSESSMENT diet and health histories

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Early consequences of deficiency

• Subclinical deficiency
• early stages decline in nutrient stores in the
  body
• No signs
• Covert
• Abnormal functions in the body
• ASSESSMENT lab tests

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Results of subclinical and covert deficiency

• Overt conditions physical signs and symptoms
• ASSESSMENT physical exam, anthropomorphic
  measures in addition to lab tests

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Diet and health

• Prevention
• Scurvy, rickets
• Chronic disease
• Nutrient and energy excess diabetes, CV diseases

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Risk factors and disease

• Condition or behavior associated with increased
  frequency of a disease
• Not a proven cause
• Risk factors can cluster-e.g., obesity, high
  b.p., high cholesterol associated with heart
  disease
• Poor diet can be a risk factor in some chronic
  diseases CV

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Leading causes of deaths in U.S.

• 28 Heart disease
• 22.7 cancers
• 6.4 strokes
• 3 diabetes mellitus

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Factors death in U.S.

• 18 tobacco
• 15 poor diet and inactivity
• 4 alcohol

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Population assessments

• National surveys
• National goals
• HEALTHY PEOPLE program identifies a nations
  health priorities and sets guidelines and goals
  to promote health and prevent disease

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The end