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3 Types of Fats / Lipids
- Triglycerides
- Phospholipids
- Sterols
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Triglycerides
- same form in which most body fat is stored
- tri = 3 fatty acids attached to a 3 carbon glycerol backbone
- fatty acid = long chain of carbon and hydrogen atoms
- triglycerides = 1 fatty acid + 3 carbons
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Fats - Chains
- determined method of digestion, absorption, function, saturation
- short chain: <6 carbon atoms
- medium chain: 6-12 C
- long chain: 14+ C
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Fats - Level of Saturation
- saturated = most hydrogen
- unsaturated = less hydrogen (monosaturated and polyunsaturated fatty acids)
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Saturated Fat
- No double bond carbon molecules
- Naturally always form straight rigid chains
- Pack together tightly
- Solid at room temperature
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Unsaturated Fat
- Double carbon bond
- Naturally kink
- unable to pack tight
- liquid at room temp
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Trans Fat
- Manipulated by manufacturers to form straight, rigid fatty acid or kinks
- cis = hydrogen on the same side, kink
- trans = hydrogen attached diagonally, straight
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Hydrogenation
- Manipulating the fatty acids while processing
- Foods - resist becoming rancid
- Hydrogen molecules are added directly to unsaturated fatty acids
- Double bond partially or totally removed, fat becomes more saturated, straight
- Partially - some double bonds broken
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Essential Fatty Acid
- Required for healthy functioning but body cannot make them
- Linoleic Acid - Omega-6 (vegetable and nut oils)
- Alpha Linoleic - Omega-3 (dark green leafy vegetables, flaxseed, soybeans, walnuts, canola, fish, shellfish) / Stimulate the production of regulatory compounds that reduce risk for heart disease
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Phospholipids
- 2 Fatty Acids + Glycerol / Phosphate compound backbone
- Soluble in water, assist in transporting fats in the blood
- Help with digestion of fat
- Liver uses to make bile
- Body manufactures
- Phosphorus - mineral
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Sterols
- Found in food and the body
- Multiple ring structure
- Do not need to consume, body continually making
- Synthesizes sex hormones, bile acids, adrenal hormones, essential to human health
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Energy
(Fats)
- Primary source of energy
- 2x the energy per gram of carb or protein
- 9 kcal per gram
- more energy dense
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Major Fuel Source at Rest
(Fats)
- 30-70% of energy used by muscle organs
- Exact percentage varies due to intake of fat, activity, weight (overweight body uses protein and carbs as fuel source)
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Physical Activity
(Fats)
- Major energy source
- Best way to lose body fat
- Fat can be mobilized and used from muscle/adipose tissues, blood lipotrotein, dietary fat
- Hormone response and amount of fat depends on: level of fitness / type, intensity, duration / food ingested prior to exercise
- Fatty acid released from adipose cell - travel in blood attached to protein - to the muscles - enter mitochondria - use oxygen to produce ATP, cell's energy source
- More physically fit? More oxygen delivered to the muscle to use the fat that is delivered
- More exercise, more fat used, carb/glycogen storage limited in muscle tissue
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Adrenaline
- Rises within seconds of exercise
- Stimulates breakdown of stored fat
- Decrease insulin production
- Insulin inhibits fat breakdown
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Energy For Later Use
(Fats)
- rest, exercise, low intake
- extra protein cannot be stored
- some fat storage is essential for health
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Vitamin A
- fat-soluble
- vision, see at night
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Vitamin D
- fat-soluble vitamin
- regulating blood calcium / phosphorus concentration, bone health, blood with draw from bones
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Vitamin E
- fat-soluble vitamins
- Antioxidant, prevent oxidation of body fats
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Vitamin K
Proteins involved blood clotting and bone health
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Maintain Cell Function
(Fat)
- Membrane integrity
- Determine what enters and exits cell
- What substance can bind to the cell
- Cell fluidity - red blood cells bending thru capillaries delivering oxygen
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Protection to the body
- Pads our body
- Protects our organs
- Retain body heat
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Feel Full
(Fats)
- High energy density
- Longer to digest
- Fat is compact in size
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Fats NOT soluble in water
- Digested, absorbed, and transported differently than carbs and proteins
- Stomach - mixes and break into droplets
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Digestion of Fats
- Small intestine
- Pancreas - enzymes that break from glycerol backback 2 free fatty acids
- Gallbladder - mixing compounds (bile, body's soap)
- Majority absorbs into mucosal lining with the help from micelle
- Micelle - bile and phospholipids trap
- Fatty acids packaged into lipoprotein (chylomicron) to release and travel in bloodstream
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3 fates for dietary fat
- 1 Immediately taken and used as energy
- 2 Make lipid containing compounds
- 3 Stored for later use in muscle or adipose tissue
- adipose cell - primary storage site
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Physically Active
- Store fat in the muscle tissue first, readily available
- Fat adipose tissue is broken down first then transported to the muscle cells
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How Much Fat?
- Acceptable macronutrient distribution range for fat is 20-35% of fat per day of total energy
- Higher intake increases risk for obesity and complications
- Low intake of fat, high intake of carbs = high triglycerides
- Minimizes saturated and trans
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Dietary Reference for Essentially Fatty Acids
- Linoleic: Omega-6 (M 14-17g)(F 11-12g)
- Alpha-Linoleic: Omega-3 (M 1.6g)(F 1.1g)
- Linoleic : Alpha Linoleic = 5:1 ratio
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Recognize fats in food
- Visible fat intake has decreased over the past decade while hidden fat intake has increased
- Visible fat - easily see that we are adding (oils, butter, cream, shortening, margarine, mayo, salad dressing)
- Hidden fats - processed and prepared foods
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Fat-Free
<0.5g fat per serving
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Reduced / Less Fat
25% less than standard serving of fat
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"Light" label claim
1/3 fewer calories or 50% less than standard serving
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Saturated Fats
- Reduce intake of saturated fats
- Recommended: 7-10% total energy
- 64%of US adults exceed dietary recommendation
- Animal Products (meat and whole milk)
- Grains (baked goods, snack foods)
- Vegetables (fried, breaded, saturated in sauce)
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Fat Replacers
- Hope to reduce energy and fat intake in order to manager weight
- Do not help lose weight
- Do not help maintain weight
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