Lipids and Fats

Lipids are made out of what elements

Carbon, Hydrogen, Oxygen

Fats(Lipids) are insoluble/soluble…

insoluble in water; soluble in organic solvents(acetone, chloroform, ether)

3 major categories of lipids

triglycerides, phospholipids (emulsifier), sterols (cholesterol, vitamin D, sex hormones)

Fatty Acid

a chain of carbons linked together

What does a fatty acid chain have (groups)

carboxyl group(COOH) hydrophilic and methyl group(CH3) hydrophobic

Fatty acids are components in

phospholipids, triglycerides

Short fatty acid chain

less than 6 carbons > dairy

Medium fatty acid chain

8-12 carbons >dairy

Long fatty acid chain

more than 12 carbons > common meats, seafood, vegetable oils

Unsaturated fatty acids

a fatty acid with one or more double bonds, liquid at room temp

Monounsaturated fatty acid

fatty acid with one double bond, liquid at room temperature

Polyunsaturated fatty acid

fatty acid with 2 or more double bonds, liquid at room temperature

Omega 6

incorporated into cell membranes; precursors to compounds involved in reproduction and blood flow ex: arachidonic acid

Omega 3

in cell membranes, help reduce tissue inflammation, ex: Eicosapentanoic acid (EPA), Docosahexanoic acid (DHA) > may help prevent heat disease and clot formation

Trans Fatty acid

man-made/synthetic

Hydrogenation

process of adding hydrogen to unsaturated fats which makes it solid at room temperature

Small amounts of naturally occurring trans fatty acids are found in

dairy milk and meat

Dietary trans fatty acids from dehydrogenation are associated with

increased levels of bad or low-density lipoprotein(LDL) (bad cholesterol); or reduced levels of good or high-density lipoprotein (HDL); an increased risk for heart disease

The AHA recommends … of trans fatty acids per day or less

2g(<1% total calories)

Chemical Structure of a triglyceride

three carbon glycerol backbone and three fatty acid chains.

Triglycerides are …

the primary form of lipid found in the body

Triglycerides in the body often reflect

dietary fatty acids consumed

Phospholipid

Assist body in transporting fat through watery substance; glycerol backbone + 2 fatty acid chains + a phosphate group

Phosphate head is hydro

philic

Fatty Acid tail is hydro

phobic

Phospholipids function as

emulsifiers

Emulsifiers

blending of water and fat components

In the body phospholipids are found(3)

cell membrane, lipoproteins, transport particles for fats (cholesterol and triglycerides)

BLANK and BLANK are major components of cell and organelle membranes

phospholipids and cholesterol

Sterols/Cholesterol

made of four carbon rings

Sterols are …

vital to health and basic metabolic functions (testosterone, estrogen, vitamin D)

Liver makes most of the body’s

cholesterol

Cholesterol is (essential or not)

nonessential so we don’t need to consume it

Micelles are formed when

larger fat components and bile acids combine

Lipids are the primary energy source for … and they have …. storage capacity

the heart, virtually unlimited

How much energy does a lipid provide (kcal/g)

9

Fat supplies … of ongoing energy during rest

60%

Fats are required for the absorption of

fat soluble vitamins (Vitamin A, D, E, K)

Fat-soluble vitamin absorption decreases when

there is incomplete fat absorption or fat malabsorption

Lipid role in cell signaling

releases adipokines

Adipokines

signaling molecules for adipose tissue

Resistin(3)

increases inflammation, insulin resistance, increase in obesity

Adiponectin

Reduces inflammation, insulin sensitivity, decrease in obesity

Leptin

reduces appetite, regulates energy balance, increase in obesity but resistant to leptin

Fatty acids are … to …

precursors to eicosanoids with multiple different effects such as relaxing blood vessels, muscle contraction, immune response (aspirin slows eicosanoid synthesis), clot formation

Fatty acid deficiencies are associated with

impaired growth, reproductive failure, skin lesions, kidney and liver disorders, and subtle neurological and visual problems

Fatty acid role in organ insulation

protect and insulate vital organs (visceral fat & subcutaneous fat)

Gender differences in body fat comp

females have a greater fat, plays a role in reproductive function

Cholesterol is a precursor to many …

hormones; such as estrogen, testosterone, aldosterone, vitamin D

Fat role in foods

taste, texture (smooth) ; makes people feel full longer, satiety, slows stomach emptying, enhances flavor compounds

Chylomicrons

largest and least dense lipoprotein; transport diet-derived lipids from small intestine to the body

VLDL (very low density lipoproteins)

lipids made in the liver; collected from chylomicron remnants are packaged with proteins, shipped to other parts of the body

Low Density lipoprotein (LDL)

formed after VLDLs depository triglycerides in other tissues, cholesterol rich, deliver cholesterol to other tissues, including blood vessels, BAD cholesterol

High Density lipoprotein (HDLs)

made mostly in liver but also small intestine, removes excess cholesterol from cells, return to liver for elimination, GOOD cholesterol

LDLs and HDLs

balance each other out

Heart disease risk increases by

excess consumption of nutrients that raise blood cholesterol

Dietary cholesterol

less significant impact on blood cholesterol

Primary type of heart disease that is linked to fat intake

atherosclerosis

Atherosclerosis

build up of LDL deposits and immune cells in arteries; this causes thickening/hardening of arteries; possible reducing blood flow to areas of the heart causing ischemia; if the artery becomes completely blocked then a myocardial infarction or heart attack can happen

Ischemia

reduction of blood flow to areas of the body especially the heart

Stroke

blockage of artery supplying blood to brain

Recommended dietary intake of fats

20-35% of daily calories

Being below the dietary intake recommendation is not recommended because

it can decrease the absorption of fat soluble vitamins

Children under age 2 dietary recommendation for fat& why

30-35% of calories; growth and nervous system development depend on adequate fat intake

It is recommended that saturated fats are …

<10% of total calories; if it is above then replace it with mono/poly unsaturated fatty acids

Low calorie fats

not really digested and absorbed; 0.7kcal/g

Higher levels of saturated fat are linked to higher incidence of (disease)

breast, ovarian, colon, and prostate cancer

Consuming fatty fish and fish oil high in omega 3s are associated with lower

colon, breast, lung, esophageal, skin, and pancreatic cancers