Transcript FATS - USD 475

FAT S :
A Concentrated
Energy Source
Chapter 6
O Fat is a compound found in
food. It is one of three types
of energy that the human
body uses, the others are
carbohydrates and proteins.
https://www.youtube.com/watch?
v=3Gqo3Y6WFYA
Types
O Saturated Fat
O Unsaturated Fat
O Trans fat
Types of Fat (Lipids)
Triglycerides - The
number of double
bonds and hydrogen
atoms determine
whether a fatty acid
is saturated,
monounsaturated, or
polyunsaturated.
Saturated Fat
O Raises the level of LDL (bad) cholesterol
O Saturated fats are generally solid at room
temperature and are natural fats from
animal or plant sources. Saturated fat is
an unhealthy fat that raises blood
cholesterol and increases the risk of
heart disease.
Food Sources
O Foods high in saturated fat include: fatty
cuts of meats, skin from poultry, full fat
dairy products like butter, milk, yogurt,
cheese and cream. Many take-away foods
and processed foods, such as pies,
pastries, doughnuts, cakes and biscuits.
Saturated fat is also found in tropical oils,
like palm oil or palm kernel oil.
Unsaturated
O Unsaturated fatty acids are fats
from plants.
Unsaturated fats are usually liquid
at room temperature and are
found in vegetable oils. There
are two main types of
unsaturated fats,
polyunsaturated (liquid in fridge
too) and monounsaturated fats
(solidify in fridge).
Unsaturated fats, in moderation,
are actually necessary for good
health. They help lower blood
cholesterol levels and can
reduce the risk of heart disease
and stroke.
Monounsaturated
fatty acid
O These appear to lower LDL
(bad) cholesterol levels and
raise HDL (good) cholesterol.
O Monounsaturated fats food
sources include: Canola oil,
peanut oil, olive oil, avocados
and nuts like almonds,
pistachios, pecans and
cashews.
Polyunsaturated
fatty acid
O These may help lower
cholesterol levels.
O Polyunsaturated includes
Omega-6 and Omega-3 fats
Food Sources
O Omega-6 fats such as
soybeans and oils, sesame
and sunflower seeds, most
nuts and their oils, corn oil,
O Omega-3 fats found in fatty
fish such as salmon,
mackerel, trout, herring,
sardines and tuna.
Trans fatty acids
O These are rare in nature.
O They are created in food by
processing (partially
hydrogenating) other types of
fats and giving them a different
structure. (ex. when margarine
is made from oil) Trans fats
behave like saturated fat. They
are the most unhealthy fats to
eat and can cause heart
disease.
O Hydrogenated – breaking the
double carbon bonds and adding
hydrogen.
O Converts liquid oils into solid
fats.
Trans Fats
Benefits
O Increases shelf life.
O Adds extra flavor and texture
Cons
O Increases LDL cholesterol, which
can contribute to heart disease.
Food Sources:
O Shortening, margarines, salad
dressings, crackers, commercially
baked goods, fried foods, frozen
foods and processed foods like
salty snacks, donuts snack foods,
chocolate coatings, fast foods,
convenience foods.
Types of Fat (Lipids)
Phospholipids-lipids that have a
phosphorous-containing
compound in their chemical
structure
O Lecithin – made by the liver,
also found in foods like egg
yolks
O Is an emulsifier – added to keep
both water and fat mixed
together
O Egg yolks act as an emulsifier in
mayonnaise to prevent the oil
and vinegar from separating
Types of Fat (Lipids)
Sterols-complex molecular
structure, help make some
hormones and vitamin D
O Cholesterol – a white waxy lipid
that provides structure for all
cell membranes, made by the
body, found in every cell. Not
essential in the diet.
O Found only in animal tissues
O Excess can block arteries –
leads to heart disease.
Cholesterol
O Functions
O Helps digest fat
O Builds cells
O Makes vitamin D and some
hormones
Food Sources
O Fatty meat and poultry
O Egg yolks
O Liver and other organ meats
O Shrimp and squid
Fat Types
O Phytosterols –
compounds from plants,
similar in structure to
cholesterol
O May help lower LDL
cholesterol levels and
the risk for heart
disease
Functions of Fat
(Lipids)
O Normal growth and
development.
O Concentrated source of energy
(9 calories/gram of fat). Fat
serves as an energy reserve.
O Body stores a large share of
lipids in adipose tissue, which
serves as an internal blanket
that holds in body heat (warmth)
and insulation.
Fat Functions
O Fat acts as a shock
absorber for internal
organs. Cushions and
protects bones from injury.
O Helps the body absorb
vitamins A, D, E, and K.
They all dissolve in fat.
OLipids are part of
the structure of
every cell.
OAffects
(enhances) the
taste, texture, and
aroma of foods.
Lipid use in the
body
O Digestion and absorption
O Fat is broken down, separates
from watery contents in the
stomach, mixes with bile in the
small intestine, and absorbed by
the cells lining the intestine
O Energy
O Cells break fatty acids down to
release energy for immediate
needs or store triglycerides for
future energy needs
O Fat cells can hold an almost
limitless supply of triglycerides
Transport in the body
O Fats from your diet move efficiently
through your blood vessels to
tissues where they can be absorbed
for fuel or stored after being broken
down
O LDL (low-density lipoproteins) –
“bad cholesterol” – carry
cholesterol that is deposited in
body tissues
O HDL (high-density lipoproteins) –
“good cholesterol” – carry excess
cholesterol to the liver to be
discarded
NEWEST INFO ABOUT DIETARY
CHOLESTEROL!
O http://abcnews.go.com/GMA/video/highcholesterol-food-warning-scrapped28884162
O http://www.pcrm.org/media/news/doctors
-say-cholesterol-must-remain-nutrient-ofconcern
Needs
Calorie Makeup of Nutrients
Fats
Protein
Carbohydrates
Teen Needs
O The Dietary Guidelines
recommends no more than
20 – 35% of the total
calories in your diet come
from fats
O < 10% of your total calories
should come from saturated
fats
Teen Needs
O Active teenage boys should
eat no more than 123 g. of fat
per day
O Active teenage girls should eat
no more than 92 g. of fat per
day
O MyPlate Oils??
Guess how much?
O Suppose you choose a
quarter pound cheeseburger,
French fries, and a milk
shake for lunch. How much
fat do you think would be in
this meal?
O 43 g., 17 of which are
saturated – nearly the fat
equivalent of half a stick of
butter!
Health
Fats (esp. the wrong kind)
play a major role in the health
of your heart
O Coronary heart disease
(CHD) – disease of the
heart and blood vessels.
O Leading cause of death in
the U.S.
O http://www.cdc.gov/nchs/fast
ats/leading-causes-ofdeath.htm
Heart Health
Controllable and
Uncontrollable
Heart-Health Risk factors
O Reduce the risks of
factors beyond your
control by carefully
managing the factors
within your control!
Heart-Health Risk Factors
Uncontrollable
Controllable
Age
Smoking
Gender
High blood pressure
Ethnic Group
High blood cholesterol
Family History
Diabetes Mellitus
Excess weight
Inactivity
Stress
Health cont’d.
O Atherosclerosis –
cholesterol buildup is
called plaque, as plaque
increases, it hardens and
narrows the arteries
causing atherosclerosis
(most common form of
heart disease)
O Heart has to work
harder to pump blood
O Causes blood pressure
to rise
Health Issues
O Heart attack – a buildup
of plaque in the arteries
feeding the heart muscle
that cut off the blood
supply (nutrients and
oxygen)
O Stroke – a buildup of
plaque in the arteries
leading to the brain that
cut off the blood supply
(nutrients and oxygen)
Sources
O Visible fats – butter, fat
on meats, salad oil
O Invisible fats – baked
goods, snack foods,
luncheon meats (1 hot
dog has about 145
calories – 117 of them
come from fat)
O Other sources: milk,
yogurt, cappuccinos,
eggs, nuts, and anything
fried
To lower fat intake:
O choose lean cuts of meat
O use low-fat cooking
methods
O limit portion sizes
O Eat more fruits,
vegetables, and whole
grain products
O Choose low- or fat-free
dairy products.
O READ FOOD LABELS!!
What is fat?
O TED Talks:
O The type of fat you eat is more
impactful on your health than
the quantity. George Zaidan
examines triglycerides, the
varied molecules that make up
fat, and how to identify which
types of fat you are consuming.
O http://ed.ted.com/lessons/what
-is-fat-george-zaidan
The typical American diet has too much
bad fat (saturated and trans fat), and
not enough good fat (the mono- and
polyunsaturated fats).
Here is how you can make your diet
more healthful:
Avoid trans-fat altogether and limit
saturated fat.
Work to replace red meat with nuts,
beans, skinless-poultry, and fish
whenever possible.
Choose low-fat dairy products.
Use vegetable oils instead of butter or
margarine.
At the end of the day, you want to get
your calories from nutrient-rich foods
with the right balance of all the
essentials.
Letter to a Dietician
O You persuaded me to make
the switch from whole milk
to fat-free milk in my
household. Unfortunately, I
have not been very
successful. My husband
and children do not like the
taste of the fat-free milk
and are refusing to drink it.
How can I convince them?
O My friend is
paranoid about fat
and seems to be
going overboard in
her search for a
fat-free life. She is
trying to get
EVERYTHING to be
fat-free. What do
you think about fatfree EVERYTHING?
What would
you say?
O I am working on more
healthful eating. I have
been eating fish instead
of higher-fat meats. I fry
the fish in oil and have
French fries, it tastes
good and I’m really glad
I have made the change
to eating more fish. Do
you think I am on track?
Fats
Our Essential Questions:
What is the purpose of fat
for our body?
O Help us absorb
_________ vitamins
O Types of fats are:
________
O Three benefits of eating
low fat foods daily are
____________
Your Risk?
O What are your
personal heart health
risk factors?
O What can you do to
decrease your risks?