An Overview of Nutrition by HC121003152144


									An Overview of Nutrition
 nutrition
   – the science of foods and the substances
     they contain
 food
   – derived from plant or animal sources
       provide energy and nutrients used by
        the body for maintenance, growth,
        and repair
 diet
   – food that one consumes
       quality of ones diet affect the risk of
        chronic diseases
             Food Choices
 personal preference
   – taste
 habit
   – PB and honey
 ethnic heritage or tradition
   – eat what you grew up with
 social interactions
   – eating with friends and family
             Food Choices
 availability, convenience,
   – quick, easy, cheap??
 positive and negative
   – happy vs. gross
 emotional comfort
   – boredom, depression, anxiety
 values
   – religious beliefs, environmental
     concerns, political views, moral
              Food Choices
 body weight and image
 nutrition and health benefits
   – functional foods
       provide health benefits beyond their
        nutrient contributions
         –whole foods, fortified foods
             The Nutrients
 energy: the capacity to do work
 nutrient: chemical substance obtained from
  food and used in the body to
   – provide energy
   – support growth
   – body maintenance
   – body repair
              The Nutrients
 composition of foods
   – six classes of nutrients
       water
       carbohydrates
       lipids
       proteins
       vitamins
       minerals

 nonnutrients
   – fibers
   – phytochemicals
   – pigments
   – additives
   – alcohols
   – others
             The Nutrients
 chemical composition of nutrients
   – inorganic nutrients
       minerals
       water
   – organic nutrients
       carbohydrates
       lipids
       proteins
       vitamins
The Nutrients
              The Nutrients
 essential nutrients
   – nutrients that foods must supply
     Energy Yielding Nutrients
 nutrients that break down to yield energy for
  the body to use
   – 3 organic nutrients
       carbohydrates
       fat
       protein
           Measuring Energy
 measured in kCalories (kilocalorie)
  – in popular literature it is abbreviated as
  – thus a 50 calorie carrot is actually 50
         Energy from Food
 amount of energy gained is dependent on
  the quantity of carbs, fats or protein the
  food contains
   – carbohydrate = 4kcal/g
   – fat = 9kcal/g
   – protein = 4 kcal/g
 energy density is the measure of energy a
  food provides relative to he amount of food
   – fat has a higher energy density than
     either protein or carbohydrates
Energy Density
          Energy in the Body
 body uses energy yielding nutrients
 energy from food supports every activity the
  body does
 energy not used is stored
   – usually as body fat
 not enough energy results in < energy
  stores and weight loss
     Energy Yielding Nutrients
 in addition to providing energy they provide
   – materials for building tissue
   – regulate many activities
        Non Energy Nutrients
 water, vitamins and minerals do not yield
 vitamins
   – aid in the release of energy
   – 13 essential vitamins
   – only can function if intact
        Non Energy Nutrients
 minerals
  – found in bone, teeth, and some body
  – 16 essential minerals
  – they are indestructible, but can be bound
       interfere with body’s absorption
  – can be lost during food refining processes
        Non Energy Nutrients
 water
  – absolutely essential for life
  – most all body activities involve water
      The Science of Nutrition
 study of nutrients
  and how the body
  handles them
 nutritional research
   – follows the
     scientific method
        Nutritional Research
 important considerations
   – controls
   – sample size
 placebo effects
   – blind experiments
   – double-blind experiments
       Dietary Reference Intakes

 the “alphabet soup” of nutrition
   – DRI
   – EAR
   – RDA
   – AI
   – UL
 DRI: Dietary Reference Intakes
 standards defining the amount of energy,
  nutrient, and physical activity for health
 recommendations apply to healthy people
 EAR, RDDA, AI and UI are all different
  nutrient values that make up the DRI
 estimated average requirements
   – average amount of a nutrient that will
     maintain a specific body function in ½ of
     the population
   – used to establish RDA
 recommended dietary allowances
   – nutrient recommendation for everyone
       similar age and gender
   – set at the upper end of the range
 adequate intakes
   – used when insufficient evidence is
     available to determine an EAR to
     establish a RDA
   – based on observation or estimates
                        UL           Danger
                                    of toxicity

                                                  Upper Intake


 tolerable upper intake levels                   RDA or AI

   – maximum daily intake of a                    Estimated
     nutrient that is unlikely to
     cause adverse health               of
    Energy Recommendations
  – Estimated Energy Requirement is not
  – average, daily dietary energy (kcalories)
    for maintenance
  – balance is important
      too much can lead to weight gain
 Acceptable Macronutrient Distribution
  – composition of a diet that provides
    adequate energy and nutrients
      45-65% from carbohydrates
      20-35% from fat
      10-35% from protein
             Using Nutrient
 nutrient recommendations are often
  misunderstood and/or controversial
 facts to help clarify
        Nutrition Assessment
 used to determine overnutrition or
 undernutrtion
   – deficiency of energy
       thinness, losing muscle tissue,
        prone to infection
   – deficiency of nutrient
       hair loss, depression, night
        blindness, skin rashes,
        bleeding gums
         Nutrition Assessment

 overnutrition
   – too much energy
       weight gain
   – overdose of a nutrient
       hot flashes, yellowing ski, rapid heart
 deficiency or excess of energy
  or nutrients over an extended
  period of time
 symptoms are easy to miss
   – can be detected with proper
     assessment tools
        Nutrition Assessment
 historical data
 anthropometric data
   – height, weight
 physical exam
 lab tests
   – blood, urine
     National Nutrition Surveys
 information gathered from surveys set public
  policy on
   – nutrition education
   – food assistance
   – food supply regulations
   – research priorities
        National Health Goals
 Healthy People 2010
  – goals are reevaluated every 10 years and
  – nutrition is a part of the plan
      basically eat better to gain or maintain a
       healthy weight for all ages and all
            Diet and Health
 diet is important in
  maintaining a healthy
 risk factors
   – behavior or condition
     that has a strong
     association with a
       obesity and heart
                 Risk Factors
   tobacco
   obesity
   alcohol
   firearms
   sexual behavior
   illicit drugs
   physical activity

 risk factors tend to cluster
      Nutrition Information and

 not everything on the Internet is true!!
 not everything on the news is accurately
 finding credible information
   – government health agencies
   – volunteer health agencies
   – reputable consumer groups

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