ch. 6 nutrition

cheif fxn of fat

energy storage

Cushions skin
Thermoregulation -
insulation blanket to
reduce heat loss/maintain
body temperature
 Gives shape to the body

visible fat

In every cell membrane
Component of myelin
Brain tissue is rich in fat
Shock absorber to protect
Constituent of hormones
and biochemicals
 Vitamin D

Invisible fat

Usefullness of fats in foods

palatabilitysatiety (stay full longer)better aroma

Fat soluable vitamins


3 lipids

Triglycerides (fats and oils) Phospholipids Sterols

are lipids soluable in water?


are lipids soluable in organic compounds?


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


Act as tiny rowboats ferrying hormones and fat soluble vitamins through blood and across cell membranes


Fat and alcohol compounds with no calories
Structure similar to cholesterol
Ex: vitamin D, testosterone, cholesterol


Breakdown of triglycerrides

three fatty acids and a glyceride

are triglycerides saturated or unsaturated?


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


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
Differ on the basis of length and degree of

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

Monounsaturated fatty acid (MUFA)

Contains two or more points of

Polyunsaturated fatty acid (PUFA)

Contain only one double bond


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


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


Why are trans/cis fats added to food

to keep them from spoiling...resist oxidation

how much trans fat in margarin


Component of cell membranes
 Lecithin and Sphingomyelin
 Lipid transport as part of lipoproteins
Food sources
 Egg yolks, liver, soybeans, peanuts


Component of cell membranes
Precursor to other substances
 Sterol hormones
 Vitamin D
 Bile acids
 Made in the liver
Food sources
 Found only in animal foods
 Forms major parts of plaques that narrow arteries in
 The underlying cause of heart attacks and strokes


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


Without CHO, the incomplete breakdown of fat produces ketones through


With no gallbaldder what do you have to reduce

fat intake

split fatty acids from glycerol


?%of dietary fat and ?% of dietary
cholesterol is absorbed


Once absorbed into the lymphatic system, fats are packaged with protein into


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


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

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


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