Fat

Question 1

Lipids

Answer 1

• all fats and oil
• divided into 3 groups:
• triglycerides, phospholipids, sterols
• most foods contain lipids
• 9 calories/gram (more energy dense than protein/carb)

Question 2

Functions of Fats and Oils

Answer 2

• concentrated sources of energy
• building blocks for cell membranes
• padded protection for organs and cells
• nerve insulation and transmission
• regulation of body temp.
• provide satiety
• stimulation of gastric reflex
• carriers of fat soluble vitamins, betacarotene, CoQ10
• precursors of steroid hormones and prostaglandins
• make up 60% of brain

Question 3

Short Chain Fatty Acids

Answer 3

• made by colonic bacteria from soluble fiber
• bile not required for digestion
• easier to digest for those with compromised liver
• absorbed directly into lymph system
• easily burned for energy

Question 4

Medium Chain Fatty Acids

Answer 4

• our body metabolizes and burns these for energy
• these oils are not stored as fat
• often used by athletes for energy

Question 5

Long Chain Fatty Acids

Answer 5

• EFAs fit here
• more difficult to digest than short or medium chain fats
• can be stored as fat more readily

Question 6

Saturated Fats

Answer 6

• primarily used for energy
• solid at room temp.
• least vulnerable to oxidative damage even when heated
• dairy, coconut, palm oil, tallow
• safe to sauté with

Question 7

Monounsaturated Fats

Answer 7

• liquid at room temp.
• less stable than saturated fat
• damaged by high heat and refining
• only 1 double bond

Question 8

Polyunsaturated Fats

Answer 8

• 2 or more double bonds
• less stable than PUFAs and saturated fat
• omega 6 and omega 3: do not heat!

Question 9

Trans Fats

Answer 9

• a straightened configuration of a normally curved, unsaturated fatty acid
• lab/industrially made
• our bodies have no enzymes that recognize these

Question 10

Digestion of Fats

Answer 10

• occurs in mouth, stomach, mostly small intestine
• lingual and gastric lipase, bile salts, pancreatic lipase
• pancreatic enzymes break down at 10 g/fat/hour

Question 11

Fat Distribution and Storage

Answer 11

• distributed via lymph system and blood stream
• in liver, fat is packaged with lipoproteins (HDL, LDL, etc) which then carry to cells
• receptors on cell membranes receive and unload
• if cells don’t need this fuel, fats are stored as body fat

Question 12

Triglycerides

Answer 12

• comprise 95% of fats in food and in our bodies
• 1 glycerol molecule + 3 fatty acids
• digested by lipase

Question 13

Triglyceride Functions

Answer 13

• insulation material
• store energy reserves
• excess sugars converted to these
• store body’s reserve of EFAs
• carriers for fat-soluble nutrients
• exercise lowers serum triglycerides/burns excess fat, converts to energy

Question 14

Phospholipids

Answer 14

• fat derivative
• building block of cell membranes
• holds proteins in place in membranes
• emulsifiers
• keep cell membranes soft and pliable
• conduction of nerve impulses
• part of myelin sheath surrounding nerve fibers

Question 15

Sterols

Answer 15

• fat-like substances present in animal tissue

- cholesterol, vitamin D, steroid and sex hormones

Question 16

Cholesterol

Answer 16

• found only in animal products
• NOT bad but excess or oxidized can be bad
• critical component of cell membranes, brain/spinal cord
• not used for energy as triglycerides are
• synthesized primarily in liver (even if none is in diet)
• adds rigidity to cell membranes
• we need this to make steroid hormones

Question 17

Essential Fatty Acids

Answer 17

• we can’t make these fats, we must eat them
• omega 6 (LA, GLA, AA)
• omega 3 (ALA, EPA, DHA)

Question 18

Omega 6

Answer 18

• found in excess in SAD
• at least 1-2% daily calories should come from these,
  3-6% optimal
• linoleic acid (LA): safflower, soy, corn, walnut oils
• gamma linoleic acid (GLA): borage, black currant, evening primrose oils, spirulina —-> eczema, PMS

Question 19

Omega 3

Answer 19

• most of us deficient
• lowers blood cholesterol and triglycerides
• brain development and function
• reduces inflammation, keeps blood thinner/healthier
• arachidonic acid (AA): animal meats, dairy, eggs
• alpha linolenic acid (ALA): flax, chia, pumpkin seeds, walnut, dark leafy greens
• eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA): fish oil, mother’s milk

Question 20

Therapeutic Use of EFAs

Answer 20

• CVD
• weight management
• epilepsy
• eczema
• inflammation and pain
• PMS and menstrual symptoms
• depression