Ch 5: The Lipids Flashcards
Energy Density
1 gram of fat has more than 2x the energy of 1 gram of carbohydrates or proteins
Satiety
adds to the feeling of being full
What are the 3 classes of lipids (fats)?
- triglycerides (95%)
- phospholipids
- sterols
Triglycerides
most fat in the body is in this form
-three fatty acids attached to a glycerol backbone
Fatty acids differ in ___ and ____ of saturation
length
degree
Saturated fats
carried maximum number of hydrogen atoms
Monounsaturated fats (MUFA’s)
has 1 point of unsaturation (a double bond- missing a hydrogen)
Polyunsaturated fats (PUFA’s)
has 2 or more points of unsaturation
where are saturated fats found
animal fats (lard)
full fat dairy
coconut and palm oil
where are monounsaturated fats found
olives, olive oil, avocados, peanuts, canola oil, peanut oil
where are polyunsaturated fats found
omega 3, omega 6
where is omega 3 found
fatty fish (salmon, mackerel, sardines, tuna) flaxseeds, walnuts, chia seeds
where is omega 6 found
plants oils, nuts, seeds
phospholipids
contain a glycerol backbone with 2 fatty acids attached
what is found in egg yolk, a phospholipids and used was an emulsifier in mayo
lecithin
sterols
large rings of carbon atoms
cholesterol
found in all animal cell membranes
non- essential (your body can make it)
does not travel freely in blood
cholesterol serves as the raw material to make:
bile: emulsifier
vitamin d: sterol (made from cholesterol )
steroid hormones: sex hormones are sterols
lipids demand special handling because they are
insoluble in water and body fluids consists largely of water
New FDA regulation
removed trans fats from GRA’s list:
new requirement to remove hydrogenated oils in ingredients
a diet too high in saturated fats has been associated with an increased risk of
heart and artery disease
lipoproteins
transport fat in the body
chylomicrons
formed with phospholipids and proteins to travel via lymph to liver
VLDL
very low density lipoproteins carry Triglycerides from liver to body cells
LDL
low density lipoproteins carry triglycerides to tissues and are made from VLDLs
total fat intake
20-35% of total calories
saturated fat intake
less than 10% of total calories
the body cannot make essential fatty acids so they must be obtained by
diet
2 main essential fatty acids
linoleic acid: omega 6
linolenic acid: omega 3
essential fatty acids
you have to digest because your body can’t make them
functions of fat
energy storage
padding fats protect internal organs
insulation fats insulate the body from extreme temperatures
HDL
desirable cholesterol
high density lipoproteins carry cholesterol away from tissues to the liver for disposal
HEALTHY
Recommended # of servings a week for fatty fish
minimum of 2 servings a week
a serving is only 3oz