-
cheif fxn of fat
energy storage
-
Cushions skin
Thermoregulation -
insulation blanket to
reduce heat loss/maintain
body temperature
Gives shape to the body
Breasts
Hips
Tummy
Thighs
Buttocks
visible fat
-
In every cell membrane
Component of myelin
Brain tissue is rich in fat
Shock absorber to protect
organs
Constituent of hormones
and biochemicals
Vitamin D
bile
Invisible fat
-
Usefullness of fats in foods
- palatability
- satiety (stay full longer)
- better aroma
-
Fat soluable vitamins
ADEK
-
3 lipids
- Triglycerides (fats and oils)
- Phospholipids
- Sterols
-
are lipids soluable in water?
no
-
are lipids soluable in organic compounds?
yes
-
Simple lipids
- Fats – solid at room temperature
- Oils – liquid at room temperature
- Contain only fatty acids and glycerol
-
Fats that make adipose tissue and burn for energy
95% of all lipids in foods and the human body; chief form of fat in foods
Triglycerides
-
Act as tiny rowboats ferrying hormones and fat soluble vitamins through blood and across cell membranes
phospholipids
-
Fat and alcohol compounds with no calories
Structure similar to cholesterol
Ex: vitamin D, testosterone, cholesterol
Sterols
-
Breakdown of triglycerrides
three fatty acids and a glyceride
-
are triglycerides saturated or unsaturated?
both
-
fxns of tryglyccerides
- Energy source and reserve
- Insulation and protection
- Carrier of fat-soluble vitamins
-
An organic compound, three carbons long Serves as the backbone for triglycerides
Glycerol
-
Organic acids composed of carbon chains
of various lengths
Each has an acid end and hydrogen
attached to all of the carbon atoms of the
chain
Differ on the basis of length and degree of
saturation
Fatty acids
-
Sources of omega-3 fatty acids
- Soybean, canola, walnut, flaxseed oils
- Salmon, tuna, mackerel
-
Sources of omega-6 fatty acids
- Vegetable oils
- Nuts and seeds
-
Every available bond from the
carbons is holding a hydrogen
Saturated fatty acid
-
Contains one point of
unsaturation
- Monounsaturated fatty
- acid (MUFA)
-
Contains two or more points of
unsaturation
- Polyunsaturated fatty acid
- (PUFA)
-
Contain only one double bond
MUFA
-
MUFA's do what to HDL, LDL, tryglycerides, and VLDL
increase HDL and lower the rest
-
Sources of MUFA's
- Olive oil,
- canola oil,
- avocados,
- pecans,
- almonds,
- peanuts,
- peanut oil
-
Contain two or more double bonds
PUFAs
-
PUFA's found in
- Corn oil, fish, nuts, seeds, canola oil,
- sunflower oil, safflower oil
-
What do PUFAs do to cholesterol and LDL
lower them
-
Omega-3 and Omega-6 fatty acids
belong to this family
PUFAs
-
Why are trans/cis fats added to food
to keep them from spoiling...resist oxidation
-
how much trans fat in margarin
50%
-
Component of cell membranes
Lecithin and Sphingomyelin
Lipid transport as part of lipoproteins
Emulsifiers
Food sources
Egg yolks, liver, soybeans, peanuts
phospholipids
-
Component of cell membranes
Precursor to other substances
Sterol hormones
Vitamin D
Bile acids
Glucocorticoids
Synthesis
Made in the liver
Food sources
Found only in animal foods
Forms major parts of plaques that narrow arteries in
atherosclerosis
The underlying cause of heart attacks and strokes
Sterols
-
liver uses cholesterol for what?
bile production
-
cholesterol fxns
- Structural component of all cell
- membranes
- Enables nerve cells to send/receive
- messages
- Precursor for sex hormones (estrogen and testosterone), aldosterone, and bile acids
- Building block for Vit D
- Enables gallbladder to make bile acids,digestive chemicals for fat and fat soluble vitamin absorption
-
Where can you get cholesterol?
animal products
-
the average person has how many fat cells?
40 billion
-
excess fat is stored in
lipocytes
-
Without CHO, the incomplete breakdown of fat produces ketones through
gluconeogenesis
-
With no gallbaldder what do you have to reduce
fat intake
-
split fatty acids from glycerol
Triglycerides
-
?%of dietary fat and ?% of dietary
cholesterol is absorbed
-
Once absorbed into the lymphatic system, fats are packaged with protein into
chylomicrons
-
Chylomicrons transport triglycerides to fat depots in the.. (3)
- Muscles
- Breasts
- Insulating fat layer under the skin
-
Serve as transport vehicles for lipids in blood and lymph
lipoproteins
-
major types of lipoproteins
- chylomicrons,
- VLDLs,
- LDLs, and
- HDLs
-
Carry triglycerides and other lipids made in the liver to the body cells for their use
Very-low-density lipoproteins (VLDL)
-
Transport cholesterol and other lipids to body tissues
Made from VLDL
Low-density lipoproteins (LDL)
-
Carry cholesterol from body cells to the liver for disposal
Acts like Pac-Man
High-density lipoproteins (HDL)
-
Lipoproteins and
Heart Disease Risk
Risk factors that cannot be changed 3
- Increasing age
- Being male
- Family history of premature heart disease
-
Which raises blood cholesteral more, sat. food fats and trans fats or food cholesterol?
sat. food fats and trans fats
-
What is linoleic acid
omega 6
-
What is linolenic acid
omega 3
-
The only PUFA's that cannot be synethesized by the body
omega 3 and 6
-
eicosanoids
compounds that regulate body functions
Made by?
Omega 3 and 6
-
Provide raw material for eicosanoids
Serve as parts of cell membranes
Contribute lipids to brain and nerves
Promote normal growth and vision
Maintain outer structures of skin/protect from
moisture loss
Help regulate metabolism
Support immune cell functions
Linolenic and linoleic acid
-
Necessary for growth, reproduction,
and skin integrity
Essential fatty acid (must come from diet)
Found primarily in:
Safflower oil, sunflower oil, corn oil,
sesame oil
omega 6
-
A polyunsaturated fatty acid
Can be used to produce other omega-3 fatty acids
Include eicosapentaenoic (EPA) and docosahexaenoic
(DCA) acids
omega 3
-
single greatest contributor
of saturated fat in the diet
cheese
-
Overconsumption of Fat is
Implicated in…
- Obesity
- Hyperlipidemia (elevated blood lipids
- and triglycerides)
- Diabetes mellitus
- Fatty liver
- Some cancers
- 1/3rd of deaths due to cancer are attributed to
- diet and physical activity
-
effects of too little dietary fat
- Fat malabsorption (cystic fibrosis, inflammatory
- bowel disease)
- Very low fat diets (<10% calories from fat)
- Premature infants
- Severe alcoholics
- Anorexics
-
Effects of Too Little Dietary Fat
Deficiency symptoms may occur after a few weeks
- Dry, scaly skin
- Hair loss
- Impaired growth
- Impaired wound healing
- Visual impairment
- Impaired reproductive ability
-
Dietary guidlines for fat
- Choose a diet that Provides 20%-35% of its calories from fat
- Keeps saturated fat intake below 10% of caloric intake
- Keeps trans fat intake below 1% of calories
- Substitute MUFA’s or PUFA’s for saturated and trans fat
- Contains fruits, vegetables, and whole grains
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