Transcript Kin 110 Lecture 2

Kin 110 Lecture 2
Chapter 2
Tools for Diet Design
Chapter 3
Human Body
Overview of Lecture 2
• Chapter 2
•
•
•
•
•
•
Definition of Healthy diet
Food Guide and its uses
Dietary Guidelines
Recommended Nutrient Intakes
Food Labeling
Nutrient Density and the Exchange
System
Chapter 2
Tools for Diet Design
• What do we need to eat to avoid
diet related disease?
• A variety of foods balanced by a
moderate intake of each food
• variety for all nutrients
• focus on main food groups
• stay physically active
• VARIETY, BALANCE and
MODERATION
Variety
• Choose a number of different
foods within any given food
group
• not the same thing “day after
day…”
• WHY ?
Balance
• Select from 5 food groups
–
–
–
–
–
four in Canada
Dairy
Vegetable / Fruit
Grains
Meats and Alternates
• fats, oils and sweets can be
added for flavour and nutrients
Moderation
• Plan your day in order to juggle
nutrient sources
• balance between types of foods
• morning vs. evening and within
meal
• moderation of high fat and salt
• Without adopting basics of
variety, balance and moderation
you risk nutrition related
disease
Nutritional Status
• Overall body health is
determined by the sum of its
nutritional status for each
nutrient
• Components Include
• Anthropometry
• Biochemical measurement
• Clinical Examination
• Dietary History
Nutritional Categories
• Desirable Nutrition
•
Intake supports body
functions
Under Nutrition
• Nutrient intake does not meet
body needs
• body enters state in which it can
not function appropriately
• body stores can make up for
short term, but become depleted
• serious problems can arise over
longterm
Over Nutrition
• Prolonged over consumption of
more than the body needs
• long term can lead to toxic build
up and serious disease
• most common is excess energy
intake
– excess weight leads to serious
disease
Limits of Nutritional
Assessment
• Can be a very long time
between the onset of poor
nutritional health and the first
clinical evidence
• Often too late
• Calcium deficiency - low bone
density, osteoporosis later in life
( 30 to 50 years).
• High Cholesterol - builds up in
circulatory system, heart
disease later in life.
Food Guide
• Rainbow in Canada, Pyramid in
USA ( see appendix B)
• Nutritionists have always
worked to put the science of
nutrition into practical terms
that could be useful to everyone
• Goal of this class is to become
very familiar with the
recommendations and the
fundamentals that create the
guidelines
Food Guide
• Estimates are based on 12001400 kcal intake (minimum)
• Expect an increase in caloric
intake to meet energy needs
• Recent changes have increased
fruit, vegetable, bread and
cereal contributions to provide
more calories and moderate fat
• oils and sweets used to
supplement energy needs, not to
replace other foods
Four Groups
•
Group
• Grain Products
•
Servings
• 5 - 12
• Vegetables and
Fruit
• Milk Products
• 5 - 10
• Meat and
Alternatives
• 2-4
• Youth, and
pregnant
women 3 - 4
• 2-3
Summary (Appendix B)
• Enjoy a variety of foods
• Emphasize cereals, breads,
other grain products, vegetables
and fruits
• Choose low-fat dairy products,
lean meats, and foods prepared
with little or no fat
• Achieve and maintain a
healthful body by enjoying
regular physical activity and
healthful eating
• limit salt, alcohol and caffeine
Menu Planning
• Utilizing the food guide as a
tool
• emphasize variety as no one
food is essential nor does one
provide all the necessary
nutrients
• Each member of food group
contributes slightly different
nutrients (appendix A)
Recommendations for
Choices
• Low fat items from milk group
• vegetables high in protein,
minerals and fiber (lentils)
• vegetables rich in Vitamin A
(dark green) and fruits rich in
vitamin C (oranges)
• Choose whole grain breads,
cereals and pastas
• refining flour eliminates most
nutrients
Sample Daily Diet
• See Table 2 - 6
• meets all requirements for 1600
- 1800 kcal
• modify for greater caloric
expenditure
• if less caloric expenditure,
increase physical activity
Evaluating Diet
• Most in US failed to meet
theses guidelines
• Very low on Fruit and
Vegetables, high on sweets, fats
and oils
Dietary Guidelines
• Different method for Menu
Planning
• KNOW THE DIFFERENCES
AND APPLICATIONS
• Food guide designed to have
nutrients met
• Main dietary problems are
associated with over
consumption of energy, Fat,
cholesterol, alcohol and salt
• Also, under consumption of
calcium, iron, B vitamins, Zinc
and fiber
Dietary Guidelines
• Dietary guidelines established
in light of these disease
concerns
• refer to intake over a day or a
week
• 1. Eat a variety of foods
• 2. Balance intake with activity
•
•
•
•
•
30 min of moderate activity a day
low fat options and nutritious snacks
high risk with abdominal fat
slow controlled weight loss
habit forming changes
Dietary Guidelines
• 3. Emphasize grains, fruits and
vegetables (nutrients and fiber)
• 4. Low fat, saturated fat and
cholesterol (low fat options, animal
products= saturated fat and cholesterol)
• 5. Moderate sugar intake
• 6. Moderate salt (sodium)
• 7. Moderate alcohol
• BP, stroke, heart disease,
cancer,……
• two or fewer servings
Recommended Nutrient Intake
(RNI)
• Corresponds to RDA
(Recommended Dietary Allowance in US)
• Recommended intakes of
nutrients that meet the needs of
almost all healthy people of
similar age and gender
• Used for
• large group meal planning over 3 - 7
days
• schools, hospitals, dormitories
• developing education programs and
food labeling standards
• developing new foods (astronauts)
• evaluating diet survey data
RNI
• Developed by :
• estimating what average people
require and individual variation
• increasing this by 30-50 % to
cover all population
• increasing again to cover losses
with cooking and specific needs
• incorporation of scientific
judgment to create estimates
without available data
RDA
• You should not expect a benefit
from eating in excess of RDA
• Revised every four years
• recently focused on presentation
and refinement of
recommendations for age
groupings
• considerations of new research
such as the antioxidant effects
of Vitamin C
Daily Values
• Recommendations based on
daily requirements versus
weekly (RNI/RDA)
• used for food labeling as they
are more generic general
estimates for the whole
population
• Reference Daily Intakes (RDI)
• Daily Reference Values (DRV)
Nutrient Density
• Used to assess nutritional
quality of individual foods
• comparison of its vitamin or
mineral content to its energy
provision. Higher the better.
• Fig 2 - 3, p 58
• avoid empty calorie foods.
The Human Body :
A Nutrition Perspective
• Various body systems are used
to aid in digestion and
absorption of food products
• Digestion - breakdown of food
substances
• Absorption - transport of food
substances into circulatory or
lymph system within body
Organization
• Cell - basic building blocks of
life, each performing a
specialized job, determined by
selective expression of DNA
• Tissue - collection of cells
designed for specific function
• Organs - groups of tissues
designed to perform specific
function eg. Heart
• Organism - comprised of organs
acting in a coordinated manner
to support life
Circulatory System
• Fig. 3-3, p 79
Regulatory (Control) System
• Hormonal and Nervous systems
• hormone - compound with
specific site of synthesis and
release into bloodstream
• eg. Insulin, gastrin
• nervous system regulates
release of acids and intestinal
motility, food acquisition,
preparation, choice...
Anatomy and
Physiology of Digestion
• Gastrointestinal Tract (GI) - site
of digestion and absorption
• hollow tube, within which food
moves and mixes with digestive
acids and enzymes, facilitating
breakdown for absorption
• large surface area to facilitate
absorption
• movement regulated by
sphincters between major
sections, allows full preparation
Anatomy of GI
• Fig. 3-4, p 81
• Secretions
– Table 3-2, p 80
Digestive Process
• Enzyme Fig 3-7, facilitate one
specific reaction repeatedly.
• Different enzymes in different
sections of the GI
• Stomach
• protein digestion, acid and enzymes
• stomach protected by mucous layer
• Small Intestine
• Chyme - mixture of stomach
secretions and food
• entry of chyme into SI slow
• triggers release of bicarbonate and
enzymes
Absorption
• Fig 3-9, p 88
• Occurs mainly in SI, 95 % of
what it receives
• massive surface area, due to
folding and finger like villi
• passive absorption - natural
movement from high to low
concentration (fats, water)
• active absorption - uses carrier and
energy (glucose)
• facilitated absorption - uses carrier
without energy