TYPES OF FATS
FATS 101
Fats (lipids) are a class of nutrients.
Fats are solid at room temperature (animals)
Oils are liquid at room temperature(plants)
Monomer is fatty acid = glycerol (alcohol) +
Fatty acid (w/a Carboxyl group)
Lipids are made of the elements C,H,O
Lipids are organic molecules
Lipids are macronutrients
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FATS 101
CONTINUED
Fats include:
1. Triglycerides (what we see as fat in our
food) are classified as saturated and
unsaturated.
2. Sterols (including cholesterol) – not
essential
3. Phospholipids (example, lecithin) – not
essential
WHY DO WE NEED FATS?
 Major source of energy for the body
(measured as Calories):
 Energy dense (9 kcal /g). More than 2x
the energy in carbs (4 kcal /g) or protein
(4 kcal /g).
 When eaten in moderation, fat is
important for proper growth,
development, and maintenance of good
health.
WHY DO WE NEED FATS?
 Insulation
 Protection
 Aids in the absorption of vitamins A, D,
E, and K.
 As a food ingredient, fat provides taste,
consistency, and stability and helps you
feel full.
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SOURCES OF DIETARY LIPIDS
OMEGA-3 FATTY ACID
Primarily from fish oil
Also found in canola or
soybean oil
Necessary for the efficient
functioning of the brain and
the body at a cellular level
2 servings of fish per week
OMEGA-6 FATTY ACID
Found in vegetable
oils
Anti-inflammatory,
maintains healthy
skin, hair and nails
and hormonal and
emotional balance.
Only need ~ 1
tablespoon a day
Heart attack grill (CBS)
http://www.youtube.com/watch?v=zbKRSYAuSNg
Heart Attack Grill (Extreme Pigouts)
http://www.youtube.com/watch?v=KTKysI59HAw
REDUCE FAT
LABELS
“Low fat”
< 3 g of fat/serving
“Reduced fat” or “Less fat”
> 25% less fat than reference food
“Fat free”
< 0.5 g of fat/serving
FAT
SUBSTITUTES
Olestra (Olean)
Engineered fat
Fatty acids linked to sucrose
Not digested by enzymes or bacteria
Yields no calories
Addition of fat soluble vitamins to structure
Over-consumption may cause cramping and
loose stool
May bind to carotenoids in the meal
STEROLS
Waxy substance
Cholesterol is a
sterol
CORONARY HEART
DISEASE
Symptoms take years to develop
Plaque build-up can begin in childhood
Myocardial infarction (heart attack)
Stroke
FUNCTIONS OF CHOLESTEROL
Essential component of cell
membrane
Produced by the liver
Found only in animal
products
Forms important hormones
Estrogen, testosterone,
vitamin D
DENSITY
LDL – LOW
LIPOPROTEIN
“Bad” cholesterol
WBC remove (oxidize) LDL from
circulation
Can cause a build-up (plaque) on walls of
the blood vessels
Leads to atherosclerosis
Causes: smoking, diabetes, LDL
HDL –
HIGH DENSITY LIPOPROTEIN
“Good” cholesterol
Synthesized by liver and intestine
High proportion of protein
Picks up cholesterol from dying cells and other
sources
Levels are raised with exercise
Remove cholesterol from the blood stream
Pre-menopausal women have higher HDL
Reduce risk of heart disease
SATURATED VS. UNSATURATED FATS
The difference between saturated and unsaturated
fat is the amount of hydrogen they contain.
All fats contain carbon, hydrogen and a little
oxygen.
If the fatty acids (subunits of lipids or fats)
contain all the hydrogen possible, they are said to
be saturated.
If not completely full of hydrogen, fatty acids are
termed unsaturated.
SATURATED VS. UNSATURATED FATS
Unsaturated fat molecules are a curved
molecule with negative charges that repel
each other so they don't stick together
Because these molecules don't stick together,
they flow - both in the food and in the
arteries.
The molecules of a saturated fat are flat.
They pile up like pages in a book and stick to
each other. They don’t flow and cause
blockages.
SATURATED FATS
Solid at room temperature
Raise blood cholesterol
Animal fats are mostly saturated, such as the
fat in milk and dairy products and in meats.
Found in tropical oils (coconut oil, palm oil,
and cocoa butter)
Recommendation: No more than 10% of
daily calorie needs
MONOUNSATURATED FATS
Liquid at room temperature
Found in vegetable oils (canola, olive, and
peanut oils)
Eating foods high in monounsaturated fatty
acids may help lower LDL cholesterol levels,
keep HDL cholesterol levels high, and
decrease your risk of heart disease.
Recommendation: Up to 20% of daily
calorie needs
POLYUNSATURATED FATS
Liquid at room temperature
Found mainly in vegetable oils (safflower,
sunflower, and corn
Main fats found in seafood
Eating polyunsaturated fats in place of
saturated fats decreases LDL (bad) cholesterol
but also decreases HDL (good) cholesterol.
Recommendation: No more than 10% of
daily calorie needs
HYDROGENATION
Zapping an unsaturated oil with high pressure
hydrogen can turn the oil into saturated fat.
This hydrogenation process is how vegetable
oil is turned into margarine.
Hydrogenated fats have two major economic
advantages over natural saturated fats.
1. They are cheaper
2. They have a longer shelf life
WHAT ARE
TRANS FATS?
A trans fat is made when manufacturers
hydrogenate vegetable oil
Trans fat, like saturated fat and dietary
cholesterol, raises the LDL cholesterol that
increases your risk for CHD.
Trans fats interfere with the ability of the cells of
the body to metabolize the fats that are good for
you. This may damage cell membranes of vital
structures, such as the brain and nerve cells.
WHERE ARE TRANS FATS FOUND?
Trans fat can be found in vegetable
shortenings, some margarines, crackers,
cookies, snack foods, and other foods made
with or fried in partially hydrogenated oils.
A small amount of trans fat is found
naturally, primarily in dairy products, some
meat, and other animal-based foods.
Beginning in January 2006, trans fats were
required to be labeled on foods that contain
them.
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THE ROAD TO A HEART ATTACK
HOMEWORK
Teacher page
Links
Hydrogenated fats web quest
Due: Wednesday, November 25, 2014