Nutrition Chapter 5: fats and lipids

HDL

(high density lipoprotein) carries cholesterol from tissues to liver for disposal made in liver good health impact

LDL

(low density lipoprotein) carry cholesterol and other fats to tissues made from VLDL which becomes LDL Bad health impact

VLDL

(very low density lipoprotein) carry triglycerides and other fats from liver to tissues made in liver

lipid digestion

-Mouth: little fat digestion -Bile emulsifiers -Triglycerides breakdown -Short chain fatty acids can go directly into blood stream and into liver -Long chain fatty acids: form lipoproteins goes into lymph and then through blood to liver -Cholesterol in fiber exerted in feces Most fat is absorbed though

Fat intake recommendations

AMDR: 20-35% dietary fat no more than 10% of fat calories from saturated fat NO trans-fat

Hydrogenated oils

adds hydrogens to make it more saturated becomes more solid at room temp (margarine)

Body: energy stores

body's chief form of stored energy

chylomicrons

carry dietary fats from small intestine via lymph and blood to tissues made in small intestine

Food: transport

carry fat-soluble vitamins A, D, E, and K also some phytochemical assist in their absorption

sterols

cholesterol we make it in our body only from animal products produces hormones and bile - an emulsifier

lipoproteins (4)

chylomicrons VLDL LDL HDL

Food: satiety

contribute to feelings of fulness

Food: sensory appeal

contribute to the taste and smell of foods

Functions of fat in the body (7)

energy fuel, energy stores, emergency reserve, padding, insulation, cell membranes, and raw materials

Body: cell membranes

form the major material of cell membranes

Trans-fat

hydrogenated oils -lowers HDL -raises LDL

Body: insulation

insulate against temperature extremes with fat layer under the skin

Omega 6

linoleic food sources: -vegetable oils -nuts and seeds health: -helps blood clot

Omega 3

linolenic food sources: -cold water fish -flax, canola, soy, walnuts (must be converted) health: -lower blood pressure -prevent clots

Body: raw materials

lipids are converted to other compounds: hormones, bile, and vitamin D as needed

Food: texture

makes fried foods crisp and other foods tender

Function of fat in food (7)

nutrients, transport, energy, sensory appeal, appetite, texture, satiety

Phospholipids

one glycerol backbone 2 fat soluble fatty acids 1 water soluble phosphate head make up cell membranes arrange themselves so phosphate heads point out and fatty acid tails point in makes cell membrane capable of letting particular things through

Triglycerides

one glycerol backbone 3 attached fatty acids store and provide energy

Polyunsaturated fats

properties: -more than one point of unsaturation food sources: -fish -some nuts health: -decreases LDL -heart healthy

Monounsaturated fats

properties: -one double bond food sources: -nuts and seeds -avocados -peanut butter health: -decreases LDL -considered heart healthy

Saturated fats

properties: -straight chain fatty acids -solid at room temp food sources: -animal products -coconut oil health: -not as good for you

Body: padding

protect internal organs from shock cushioning with fat pads from inside body cavity

Body: energy fuel

provide 80-90% of resting body's energy much of the energy used for muscular work

Food: energy

provide concentrated energy source

Food: nutrients

provide essential fatty acids, fat-soluble vitamins, and other needed compounds

Body: emergency reserve

serve as emergency fuel supply in times of illness and diminished food intake

Food: appetite

stimulates the appetite

Triglyceride subgroups

triglyceride: saturated and unsaturated unsaturated: monounsaturated and polyunsaturated polyunsaturated: omega-3 fatty acids (linolenic) and omega-6 fatty acids (linoleic)