Fats

Chapter 4

What are fats?• Lipid molecules

– Carbon– Hydrogen– Oxygen

• Hydrophobic• Lipophilic

The terms fat and lipid will be used interchangeably in

this course.

Lipid Classification• Triglycerides

– Most common type of dietary lipid

• Phospholipids– Cell membranes– Water and

fat soluble– Help emulsify fat so it

stays dispersed in watery substances like blood.

• Sterols

Triglycerides

• Glycerol– Forms triglyceride

“backbone”– Three-carbon

molecule

• Three fatty acids– Can be of different

lengths

Triglyceride Functions

• Energy source– During rest and

exercise

• Energy reserve– 9 kcal/gram

• Provides protection– Cushioning– Insulator

(thermal/electrical)

• Vitamin carrier

Fatty Acids

• Carbon backbone• Length varies

– SCFA (< 6 carbons)– MCFA (6 to 10

carbons)– LCFA (> 10

carbons)

Fatty Acid Saturation• Saturated

– No double bonds– Saturated with

hydrogen– Solid at room

temperature• Unsaturated

– Mono and poly– Liquid at room

temperature

Fatty Acid Saturation

Omega Fatty Acids• Unsaturated• Their name is derived from position of first double

bond from methyl end– Omega 3, 6, 9 fatty acids

• Omega 3 and 6 are essential fatty acids– Linolenic and linoleic acids

• Form eicosanoids • If you would like additional information about

omega-3 fatty acids, refer to the article in the extra reading learning folder.

Hydrogenation• Addition of hydrogen

to unsaturated fat• Causes formation of

trans fats• Fats take on saturated

properties• Raises blood

cholesterol levels which is associated with increased risk for heart attack and stroke.

Phospholipids

• Structure– Glycerol backbone– Two fatty acids +

phosphate• Sources

– Egg yokes, soybeans, and peanuts

• Functions– Cell membranes– Emulsifiers– Transporters

Sterols

• Do not contain fatty acids

• Have ringed molecular structure

• Same physical properties as other fats

• Cholesterol is most common sterol

Artificial Fats

• Carbohydrate derived– Oatrim

• Protein derived– Simplesse

• Specialty fats– Olestra (Olean)– Salatrim (Benefat)

Photo © J. Helgason/ShutterStock, Inc.

Fat Intake

• No RDA or AI• 20–35% of total

calories– ~ 10% polyunsaturated– ~ 10% monounsaturated– < 10% saturated

• Avoid trans fats

Cholesterol

• Sources– Animals only

• Components– HDL– LDL– VLDL

• High levels of LDL increase risk for cardiovascular disease

Recommended Cholesterol LevelsYes, even athletes can have elevated

cholesterol levels!

Guidelines for Lowering Cholesterol• Limit saturated fat intake. (Choose oils over solid fat

most of the time)• Keep daily cholesterol intake < 300 mg. (Choose fats

from plant sources like canola and olive oil over animal sources like butter and whole milk)

• Limit trans fat intake. (Read the ingredient list. If partially hydrogenated oil is listed then the product contains trans fats.)

• Maintain active lifestyle.• Increase fruit and vegetable intake. (Make half your

plate fruits and vegetables!)

Bioenergetics of Fat

Interesting information but I do not expect you to commit it to memory

for this course.

Fat Intake: Before Exercise

• Fat Adaptation– Short-term– Long-term

• Single High-Fat Pre- Competition Meal

• Recommendations– Include fats but

keep to a minimum– Experiment with

different fat contentPhoto © Photos.com

Fat Intake: During Exercise

• Long-Chain Fatty Acids• Absorption is slow• Benefits questionable

• Medium-Chain Fatty Acids• Absorption is faster• Benefits questionable;

possible gastric upset• Recommendations

– Avoid fats during exercisePhoto © Photos.com

Fat Intake: After Exercise

• Normal dietary recommendations for fats apply- 20–35% fat content- Unsaturated fats

• Carbohydrates should predominate

• Consume post-exercise meal ASAP

Photo © Photos.com

FATS

• What can you take away from this chapter?

• What stands out for you?

• Are there any changes you would like to make to your sports nutrition diet now that you have this new information?