WMST 245

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WMST 245 SECTION 4 FOOD AND NUTRITION
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HUMANS NEED NOURISHMENT. THEY GET IT FROM SIX
KINDS OF NUTRIENTS ALL ARE IMPORTANT, AND THE
FIRST THREE GIVE US ENERGY

• 1. CARBOHYDRATES
• 2. FAT
• 3. PROTEIN
• 4. VITAMINS
• 5. MINERALS
• 6. WATER

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HOW MUCH FOOD DO HUMANS CONSUME EACH DAY?

• WE CANT EXPRESS THIS AS OUNCES OF CEREAL OR LBS
  OF CHEESE, BECAUSE WE CANT COMPARE THESE. WE
  HAVE TO USE AN INDEX CALLED KILO-CALORIES
• THE AVERAGE CONSUMPTION OF KCALS EACH DAY DEPENDS
  ON WHERE PEOPLE LIVE.
• THE AVERAGE IN THE USA IS ABOUT 3,770 as much as
  40 may be wasted, making the net figure 2,262.
• THE AVERAGE IN ETHIOPIA IS ABOUT 1,850

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HOW MUCH ENERGY DO WE NEED TO LIVE?

• IT DEPENDS
• AGE
• HEIGHT
• WEIGHT
• CLIMATE
• MALE OR FEMALE
• WORK/ACTIVITY
• PREGNANT OR LACTATING?

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HOW MUCH ENERGY DO WE NEED TO LIVE?BASAL
METABOLIC RATE (BMR) IS THE MINIMAL EXPENDITURE
OF ENERGY COMPATIBLEWITH LIFE
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HOW MUCH ENERGY DO WE NEED TO LIVE?ADULT
PHYSICAL ACTIVITY LEVEL (PAL)MULTIPLY BMR BY THE
PAL COEFFICIENT
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Women Work Crew Builds a Road in Lesotho, 1969
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Women working with plow in the field As women
struggle to subsist with labor and capital
scarcity, they often are forced to adjust
cropping patterns that can decrease production or
damage the environment.
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HOW MUCH ENERGY DO WE NEED TO LIVE?CHILDREN
(KCals per Day)
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HOW MUCH ENERGY DO WE NEED TO LIVE?COLD CLIMATES

• We need more energy if we live in cold climates
•  
• At 15 degrees C (59 degrees Fahrenheit) add 100
  Kcal per day
• At 10 degrees C (50 degrees Fahrenheit) add 200
  Kcal per day
• At 5 degrees C (41 degrees Fahrenheit) add 300
  Kcal per day

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Inuit women drying fox skins on a rack, at
Bernard Harbour, Northwest Territories (Nunavut)
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HOW MUCH ENERGY DO WE NEED TO LIVE?PREGNANCY
LACTATION

• To support pregnancy needs additional Kcals of
  energy, which may be obtained by reducing
  activity or increasing food consumption. The
  optimal amount of additional energy is about 96
  Kcal per day in the first trimester, 265 Kcal per
  day in the second trimester, and 430 Kcal per day
  in the third trimester. A woman who is
  breastfeeding needs an additional 500 Kcals per
  day to support lactation.

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HOW DO WE MEASURE WHETHER ANYONE IS GETTING
ENOUGH TO EAT?

• FOUR GROUPS OF MEASURES
• CLINICAL bodily symptoms like hair pigment,
  edema (swelling), eyesight problems
• BIO-CHEMICAL metabolic symptoms in blood or
  other fluids e.g. anemia
• DIETARY food intake surveys
• ANTHROPOMETRIC measurements of weight and
  height

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MONITORING GROWTH IN CHILDREN
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ASSESSING UNDER-NUTRITION WITH ANTHROPOMETRIC
MEASURES

• Weight-for-Height
• Height-for-Age
• Weight-for-Age
• Mid-Upper Arm Circumference (MUAC)
• Skinfolds
• Head Circumference
• Proxies for Length
• Body Mass Index

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BODY MASS INDEX

• BMI (BODY MASS INDEX) Weight/Height2
• When weight is measured in kilograms (kg) and
  height in metres (m), the acceptable range of
  BMI is 18.5 to 25
• e.g. someone five feet eight inches tall weighing
  150 lbs has a BMI of 22.8
• e.g. someone five feet ten inches tall weighing
  180 lbs has a BMI of 25.8
• to get in the acceptable range this person
  would need to weigh between 129 and 174 lbs
• e.g. someone five feet four inches tall weighing
  135 lbs has a BMI of 23.2
• e.g. someone six feet tall weighing 200 lbs has a
  BMI of 27.1
• e.g. someone six foot four inches tall weighing
  280 lbs has a BMI of 34.1
• e.g. someone six foot two inches tall weighing
  240 lbs has a BMI of 30.8
• Note 1 kg 2.2046 lbs 1 metre 3.280833 feet

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The degree of athletic activity is important in
assessing BMI
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DIETARY DEFICIENCIES

• THE BIG THREE
• IRON DEFICIENCY CAUSES ANEMIA, TIREDNESS,
  REDUCED CAPACITY TO WORK, INCREASED
  SUSCEPTIBILITY TO INFECTION SPECIAL PROBLEMS FOR
  PREGNANT WOMEN
• IODINE DEFICIENCY CAUSES GOITER, AND WHEN
  SEVERE, LOSS OF IQ, POOR BRAIN FUNCTION, AND
  CRETINISM IT IS THE LARGEST PREVENTABLE CAUSE
  OF MENTAL RETARDATION
• VITAMIN A DEFICIENCY CAUSES NIGHT-BLINDNESS,
  AND WHEN SEVERE, BITOTS SPOT AND TOTAL
  BLINDNESS ALSO CAUSES PREMATURE DEATH FROM
  RESPIRATORY, GASTRO-INTESTINAL DISEASE

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OTHER DIETARY DEFICIENCIES

• VITAMIN D DEFICIENCY CAUSES RICKETS (SOFT
  DEFORMED BONES, BOW-LEGGEDNESS)
• VITAMIN C DEFICIENCY CAUSES SCURVY (BLEEDING
  GUMS GUM DISEASE, LOOSENING OF TEETH)
• B-VITAMINS BERI-BERI (THIAMINE degeneration of
  the central nervous system and gastro-intestinal
  system) PELLAGRA (NIACIN dermatitis,
  gastro-intestinal problems, central nervous
  system symptoms) PERNICIOUS ANEMIA (B12)
• ZINC DEFICIENCY RETARDS CHILD GROWTH, CAUSES
  DIARRHEA, DIFFICULTY ABSORBING OTHER
  MICRONUTRIENTS

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SECONDARY MALNUTRITION

• UNDERNUTRITION ATTRIBUTABLE NOT TO LACK OF FOOD
• AVAILABILITY BUT TO INABILITY TO ABSORB
  NUTRIENTS. EXAMPLES ARE
• EATING DISORDERS
• DIARRHEA FROM INTESTINAL PARASITES OR UNSAFE
  DRINKING WATER (only a part of the food eaten is
  available to the body the rest is not digested
  properly or is shared with parasites)
• INFECTIOUS DISEASES SUCH AS MEASLES (the bodys
  immune system uses a lot of energy to try to
  fight off the diseases some of the food eaten is
  used to supply this energy to the immune system)

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Young girl receives a measles vaccination at a
health clinic in Demak, Indonesia
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UNDERNUTRITION

• UNDERCONSUMPTION OF PROTEIN AND CALORIES IS THE
  PROBLEM RELATED TO FOOD SHORTAGE
• PROTEIN AND CALORIES ARE NUTRIENTS
• THAT PEOPLE GET ALMOST EXCLUSIVELY FROM FOOD --
  NOT FROM SUPPLEMENTS OR FORTIFICATION

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UNDERNUTRITION
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• WHERE DO CALORIES AND PROTEIN
• COME FROM?
• CALORIES TRANSFORMING SOLAR
• ENERGY INTO HUMAN ENERGY BY
• PHOTOSYNTHESIS
• PROTEIN GETTING NITROGEN INTO THE
• CHEMICAL EQUATION
• LIGHTNING STORMS
• NITROGEN FIXING BACTERIA
• SEA ALGAE

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NUTRITIONAL ROLE OF PROTEIN

• 1. BUILDING CELLS THAT MAKE UP MUSCLES,
  MEMBRANES, CARTILAGE, HAIR
• 2. CARRYING OXYGEN AROUND THE BODY
• 3. CARRYING NUTRIENTS INTO AND OUT OF
• CELLS AND HELPING TO ASSIMILATE FOOD
• 4. CONTRIBUTING TO DEVELOPMENT OF
• ANTIBODIES THAT FIGHT DISEASE
• 5. WORKING AS ENZYMES TO SPEED UP
• DIGESTIVE PROCESSES

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QUALITY OF PROTEIN PROTEIN IN THE BODY IS
CONSTRUCTED FROM 22 AMINO ACIDS THE BODY MAKES
13 OF THEM, BUT 9 ESSENTIAL AMINO
ACIDS CANNOT BE MADE BY THE BODY THEY MUST BE IN
THE DIET. A FOOD THAT CONTAINS ALL 9
ESSENTIAL AMINO ACIDS IN SUFFICIENT
CONCENTRATIONS TO MEET HUMAN NEEDS IS CALLED A
COMPLETE PROTEIN
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• ANIMAL PRODUCTS (MEAT, MILK, EGGS)
• ARE COMPLETE PROTEINS
• PLANT PRODUCTS (CEREALS, LEGUMES) ARE MISSING ONE
  OR MORE OF THE ESSENTIAL AMINO ACIDS OR CONTAIN
  THE ACID IN TOO LOW A CONCENTRATION
• THE NEED FOR BALANCE AMONG THE ESSENTIAL AMINO
  ACIDS THE BODY MUST HAVE AMINO ACIDS IN
  CORRECT PROPORTIONS IN ORDER TO PRODUCE PROTEINS

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VEGETABLE VS ANIMAL?
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CALORIE DEFICIENCY APPEARS TO BE BIGGER
PROBLEM THAN PROTEIN DEFICIENCY NUTRITIONIST
NEVIN SCRIMSHAW ADULT PROTEIN NEEDS ARE MET BY
MOST TRADITIONAL DEVELOPING COUNTRY DIETS WHEN
THEY ARE CONSUMED IN SUFFICIENT QUANTITY TO MEET
NORMAL ENERGY NEEDS. 1995 FOOD AVAILABLE IN
SUB-SAHARAN AFRICA CALORIES 2144 PROTEIN 51.6
gms. If you get enough calories, chances are you
get enough protein. If you get enough protein,
you may not get enough calories.
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HOW MUCH OF A NUTRIENT IS ENOUGH?(HOW DO WE SET
STANDARDS?)

• DIFFERENT PEOPLE HAVE DIFFERENT NEEDS
• A CHILDS NEEDS ARE DIFFERENT FROM AN ADULTS
• A WOMANS NEEDS ARE DIFFERENT FROM A MANS
• A WOMEN PREGNANT OR LACTATING NEEDS MORE
• AN ACTIVE PERSON HAS DIFFERENT NEEDS FROM A
  SEDENTARY PERSON
• LIVING IN A COLD CLIMATE INCREASES NEEDS
• NEEDS DIFFER WITH HEALTH STATUS
• SOME PEOPLE HAVE DIFFERENT NEEDS FOR UNEXPLAINED
  REASONS THEY HAVE DIFFERENT METABOLISM

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EVEN AFTER SPLITTING THE POPULATION INTO
GROUPS THERE ARE DIFFERENCES IN NUTRIENT
REQUIREMENTS AMONG MEMBERS OF A SINGLE
GROUP E.G. NOT ALL WOMEN BETWEEN AGES OF 25
35 HAVE THE SAME NUTRIENT REQUIREMENTS
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Bell-shaped curve showing the distribution of
nutrient requirements in the population, and how
the RDA is set at two standard deviations above
the mean, greater than the needs for 97.5 of
the population
RDA recommended nutrient level
2.5 of the population
2.5 of the population
some people need a lot of calories or protein
average or mean level
some people need fewer nutrients than the
average person
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WHO SETS THE STANDARDS?

• IN THE USA, STANDARDS ARE SET BY THE FOOD
  NUTRITION BOARD OF THE NATIONAL ACADEMY OF
  SCIENCES INSTITUTE OF MEDICINE
• IN THE LATE 1990S, THE BOARD REVIEWED STUDIES,
  AND ISSUED MORE COMPREHENSIVE GUIDELINES
  INCLUDING THE FOLLOWING ELEMENTS
• RDA (Recommended Dietary Allowance) average
  daily intake sufficient to meet needs of almost
  all (97-98) healthy persons
• AI (Adequate Intake) estimated only when RDA
  cant be determined based on observed intakes by
  health persons
• UL (Upper Intake Level) the highest daily intake
  likely to pose no risks of toxicity for almost
  all persons
• EAR (Estimated Average Requirement) intake
  meeting the need of half of all healthy
  individuals in the population

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REFINING THE STANDARDS

• EACH OF THE REFERENCE VALUES OF THE FOOD
  NUTRITION BOARDS TAKES INTO ACCOUNT GENDER,
  DIFFERENT LIFE STAGES, BIOAVAILABILITY OF
  NUTRIENTS FROM DIFFERENT SOURCES, INTERACTIONS
  BETWEEN NUTRIENTS AND BETWEEN NUTRIENTS DRUGS,
  AND INTAKE FROM FOOD FORTIFICATION AND
  SUPPLEMENTATION
• IN JAN. 2001 THE BOARD RELEASED INTAKE
  RECOMMENDATIONS FOR VITAMINS A K, AND 12
  MINERALS arsenic, boron, chromium, copper,
  iodine, iron, manganese, molybdenum, nickel,
  silicon, vanadium, and zinc. Recommendations for
  calcium, fluoride, magnesium, phosphorus and
  selenium were released previously
• http//www.iom.edu

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• PROBLEMS WITH NUTRITIONAL
• STANDARDS
• DIFFERENT INDIVIDUALS HAVE
• DIFFERENT NUTRITIONAL NEEDS
• COMPARING DISTRIBUTIONS OF
• NEEDS AND INTAKE.
• THE NUTRITIONAL NEEDS OF AN
• INDIVIDUAL MAY CHANGE OVER TIME.
• IMPORTANCE OF QUALITY OF PROTEIN