Basic Nutrition and Diet Therapy 13th edition - Williams

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Basic Nutrition and Diet Therapy13th edition -
Williams

• Reading Assignment
• Chapters 1, 2, 3,4, 5, 6
• Presenter
• Chinazo Echezona-Johnson, RNC, MSN, LL.B

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What Is Nutrition?
-The study of how your body uses the food that
you eat.
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What is a Nutrient

• A nutrient is a chemical substance in food that
  helps maintain the body.
• Some nutrients provide heat and energy.
• All help build cells and tissues, regulate bodily
  processes such as breathing.
• No single food supplies all the nutrients the
  body needs to function.

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Six Classifications of Nutrients

• Protein
• Carbohydrates - sugars, starches, cellulose
• Vitamins
• Minerals
• Water
• Fat

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Definition of a Calorie
A unit of measure for energy in food
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Measurement of Energy

• Calorie
• Amount of energy in food or expended in physical
  actions
• Kilocalorie (1000 calories)
• Energy is measured in large calories, or
  kilocalories

How are kilocalories converted to kilojoules
(kJ)? 1 kcal 4.184 kJ
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Nutrients that have Calories

• Proteins
• Carbohydrates
• Fats

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Calories of Nutrients by Weight
1g Fat contains 9 calories 1g Carbohydrates
contains 4 calories 1g Protein 4 calories
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Variables which affect nutrient needs 1. Age 2.
Gender 3. Activity Level 4. Climate 5. Health
6. State of nutrition
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Signs of Proper Nutrition

• Well-developed body
• Ideal weight for body composition
• Adequate muscle development
• Smooth skin, glossy hair, clear and bright eyes
• Mental and physical alertness
• Ability to resist disease
• Increased life span

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Types of Nutrition Health

• Optimal nutrition
• Obtained from a varied diet
• Desired amounts should be balanced
• Undernutrition
• Less than desired amounts of nutrients
• Limits work capacity, immune system, mental
  activity

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Types of Nutrition Health, contd

• Malnutrition
• Reserves depleted
• Nutrient and energy intake insufficient
• Overnutrition
• Excess nutrient and energy intake over time
• Produces harmful gross body weight
• Excessive amounts of nutrient supplements over
  time

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MyPyramid

• Food guidance system
• Valuable nutrition education tool for the public
• Goal is to promote physical activity, variety,
  proportionality, moderation, and gradual
  improvements
• www.mypyramid.gov.

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Energy Sources

• Carbohydrates
• Primary source of fuel for heat and energy
• Maintain bodys back-up store of quick energy
• Should provide 45 to 65 of total kilocalories

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Carbohydrates

• Relation to energy
• Basic fuel source
• Energy production system
• Dietary importance
• In the typical American diet, half the amounts of
  total caloric intake is in the form of
  carbohydrates.
• Daily intake of sugars by Americans accounts for
  20 to 40 of total caloric intake.

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Special Tissue Functions of Carbohydrates

• The protein-sparing function of carbohydrates
  protects proteins, allowing them to be used for
  tissue growth and maintenance.
• Carbohydrates prevent the rapid breakdown of fats
  that would produce excess amounts of ketones.

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• Where is glycogen stored? Liver and muscles
• Which is used first to maintain blood glucose
  levels, liver or muscle glycogen? Liver
• What is glycogenesis? The formation of glycogen
  from glucose. Glycogen is synthesized depending
  on the demand for glucose

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Energy Function of Carbohydrates

• Basic fuel supply
• Energy for physical activities and all work of
  body cells
• Reserve fuel supply
• Provided by glycogen
• Maintains normal blood glucose level during
  fasting and sleep

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Energy Sources

• Proteins
• Primary function is tissue building
• Should provide 10 to 35 of total kilocalories
• Source of energy when supply from carbohydrates
  and fats is insufficient
• Proteins
• Provide amino acids
• Necessary for building and repairing tissues

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Proteins

• May provide body fuel if the supply of
  carbohydrate and fat is insufficient for needs
• Less efficient
• Plasma proteins attract water, resulting in
  maintenance of normal circulation

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Food Sources of Protein

• Complete proteins contain 9 indispensable amino
  acids sufficient to meet body needs
• Primarily of animal origin
• Egg , milk, cheese fish, poultry, seafood
• Soy (this is an exception)
• Incomplete proteins deficient in one or more of
  9 indispensable amino acids
• Primarily of plant origin
• Grains
• Legumes
• Nuts
• Seeds
• Fruits and vegetables

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Proteins

• The building blocks of proteins are amino acids
• Amino acids are necessary for building and
  maintaining body tissue.
• Some common proteins in foods
• Casein in milk and cheese, gluten in wheat,
  albumin in egg white
• Protein balance, both within the body and in the
  diet, is essential to life and health
• When would tissue need repairing from being
  damaged?
• Burns, cuts, and scrapes muscle tears after
  exercise

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Functions of Protein

• Tissue building
• Energy
• Water balance
• Metabolism
• Body defense system
• All functions are critical for optimal health.
• What is metabolism?
• Metabolism involves catabolism and anabolism
• Metabolic processes ensure that the body has
  energy in the form of adenosine triphosphate
  (ATP).

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Dietary Fiber

• Not digestible - lack of necessary enzyme
• Important in health promotion and disease
  prevention
• A diet high in dietary fiber decreases your risk
  for which diseases?

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What is catabolism? breaking down of proteins
into amino acids What is anabolism? Resynthesis
of amino acids into tissue proteins as
needed What is deamination? removal of nitrogen
from the amino acid. This is done to maintain
nitrogen balance. Nitrogen is then converted to
ammonia and excreted as urea in the urine
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Vegetarian Diets

• Lacto-ovo-vegetarian allow diary products and
  eggs. Mixed diet of plant and animal food
  sources
• Lacto-vegetarian accept only diary products
• Ovo-vegetarian the only animal food excluded
  are eggs
• Vegan no animal foods risk of protein
  imbalance
• (Careful planning is needed to ensure adequate
  nutrition)

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Digestion of Proteins

• Mouth
• Stomach enzymatic breakdown of protein by
  proenzymes (zymogens)
• Pepsin
• Hydrochloric acid
• Rennin
• Small intestine
• Pancreatic secretions
• Trypsin, chymotrypsin, carboxypeptidase
• Intestinal secretions
• Aminopeptidase, dipeptidase

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Protein

• Protein energy malnutrition
• Kwashiorkor
• Marasmus
• Excess protein
• Usually also means excess fat intake
• Protein displaces other healthy foods in diet
• Extra burden on kidneys to get rid of excess
  nitrogen

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• Kwashiorkor is common in children between ages of
  18 and 24 months who are rapidly weaned and
  switched to a diet of mostly carbohydrates and
  little protein. Characteristics include edema in
  the feet and legs and a bloated abdomen.
• What function of protein does this relate to?
  Water balance
• Marasmus is chronic energy and protein
  deficiency. Characteristics include wasting
  without edema and a skin and bones appearance.

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Importance of Nitrogen Balance

• Nitrogen balance (intake excretion)
• Positive nitrogen balance body stores more than
  it excretes
• Negative nitrogen balance body takes in less
  than it excretes
• Nitrogen balance indicates how well the bodys
  tissues are being maintained
• Positive nitrogen balance can occur during
  periods of rapid growth and pregnancy.
• Negative nitrogen balances occur during periods
  of illness or malnutrition
• During a period of negative nitrogen balance the
  person is not getting enough protein in the diet
  and the body is breaking down tissue to provide
  energy or other critical functions.

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FATS FATTY ACIDS

• Fats are not needed to supply large amounts of
  energy
• Rapid breakdown of fats produce ketones
• Fatty acids are the preferred fuel for the heart
  muscle

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Fat

• Fat digestion occurs mostly in the small
  intestine, primarily by bile, pancreatic lipase
  and intestinal enzymes
• The end products of lipid digestion are glycerol,
  fatty acids and cholesterol
• Large quantities of lipids are stored in adipose
  tissue and the liver

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Fat

• Major function of fat is to provide energy
• 1 g of fat supplies 9 cal of energy
• Also provides insulation
• protects internal organs from mechanical damage
• promotes absorption of the fat-soluble vitamins

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ESSENTIAL FATTY ACIDS

• Essential fatty acids are necessary to aid in
• tissue strength
• cholesterol metabolism
• muscle tone
• blood clotting
• heart action

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FUNCTIONS OF FAT IN THE BODY

• Provide energy
• Protect vital organs
• Insulate against cold environmental temperatures
• Flavor and satisfaction
• Facilitate the absorption of fat soluble vitamins
• (Fat substitutes are not absorbed and therefore
  do not provide energy or essential nutrients, but
  may provide flavor and satisfaction)

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Chapter 5Digestion, Absorption and Metabolism
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Digestion

• What is digestion?
• What are absorption and transport?
• Where do they begin and end?
• Mechanical Digestion
• GI motility Beginning in the mouth, muscles and
  nerves coordinate their actions to provide
  motility, an automatic response to the presence
  of food.
• What are some specific mechanical digestion
  actions that occur? Mastication and peristalsis

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Digestion
What is peristalsis?

• Muscles
• Tonic contractions ensure continuous passage of
  the food mass and valve control along the way
• Peristalsis involves periodic muscle contraction
  and relaxation
• Rhythmic waves that mix the food mass and move it
  forward

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Chemical Digestion

• Digestive enzymes Break down nutrients
• Hydrochloric acid and buffer ions Produce the
  correct pH necessary for enzyme activity
• Mucus causes chemical changes in substances to
  prepare for enyzme action. Lubricates and
  protects the stomach and intestinal tract tissues
  and helps mix the food mass
• Water and electrolytes Carry and circulate the
  products of digestion through the tract and into
  the tissues
• Bile Divides fat into smaller pieces to assist
  fat enzymes is a fat emulsifying agent

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Digestion in the Small Intestine

• Intestinal enzymes
• Carbohydrate Disaccharidases convert
  disaccharides into monosaccharides.
• Protein Enterokinase activates trypsinogen from
  the pancreas to become trypsin amino peptidase
  removes end amino acids from polypeptides
  dipeptidase splits dipeptides into amino acids.
• Fat Intestinal lipase splits fat into glycerides
  and fatty acids.

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Absorption and Transport

• When digestion is complete, food has been
  transformed into simple end products ready for
  use by cells.
• This transformation has prepared the food for
  absorption with a water base for solution and
  transport.
• Now the food is prepared for absorption as part
  of the GI circulation.

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Absorption in Large Intestine

• Water is taken up by the large intestine
• Most water in chyme is absorbed in the first half
  of the colon
• Only a small amount remains to form and eliminate
  feces
• Dietary fiber is not digested
• Contributes bulk to food mass
• Helps form feces

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Metabolic Pathway
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Review Question

• During digestion, the major muslce action that
  moves food mass forward in regular rhythmic waves
  is called
• Valve contraction
• Muscle tone
• Peristalsis
• Segmentation ring motion

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• Bile is an important secretion that is
• a. produced by the gallbladder
• b. Stored in the liver
• c. An aid in protein digestion
• d. A fat-emulsifying agent

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Energy

• Food energy is changed into body energy
• Cycled throughout the body to do work.
• The body uses most of its energy supply for basal
  metabolic needs.

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• The body needs constant energy for voluntary and
  involuntary activity
• Without storage of energy, we would need to be
  eating constantly.
• Name some voluntary and involuntary activities

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Basic Energy Needs

• Involuntary work includes all activities of the
  body that are not consciously performed
• Circulation, respiration, digestion, absorption
• Requirements include
• Chemical energy in many metabolic products
• Electrical energy in brain and nerve activities
• Mechanical energy in muscle contraction
• Thermal energy to keep the body warm

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Energy

• Energy is the force or power to do work
• How does the body supply energy during sleep?
• Glycogen stored in the liver and muscles
  maintains normal blood glucose levels during
  sleep.
• Where in the body is glycogen stored?
• Liver and muscles
• How long does the glycogen store typically last?
• 12 to 48 hours
• What physical activities have high energy
  expenditure values? Aerobics, cycling, running,
  fast walking, weight training

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Fuel Factors

• Carbohydrate 4 kcal/g
• Fat 9 kcal/g
• Protein 4 kcal/g
• Fat is the best storage form of energy. The
  caloric density of fat and that if the bodys
  major form of energy storage were protein or
  carbohydrate, it would take a much larger space
  to store the same amount of energy.

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Basic Energy Needs

• Fuel is provided in the form of nutrients
• There are only three energy-containing nutrients
• Carbohydrate is primary fuel
• Fat assists as storage fuel
• Protein is a back-up fuel source

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The END!!