Three types of lipids in foods:
* Three fatty acid molecules
* Fatty acids are long chains of carbon atoms surrounded by hydrogen atoms. * One glycerol molecule
* Glycerol is a three-carbon alcohol that is the backbone of a triglyceride
Stored in fat cells
- Unsaturated fatty acids:
- Do not stack well together
- Liquid at room temp
- Present in plants oils
Hydrogenation: the addition of hydrogen atoms to unsaturated fatty acids
- Converts liquid fats (Oils) into a more solid form
- Used to create margarine from oils
- Often creates trans fatty acids (extremely bad)
Trans fatty acids:
- Are detrimental to health
- Change the way our cell membranes function
- Reduce the removal of cholesterol from the blood.
Essential fatty acids:
- Two fatty acids cannot be made in the body and must be obtained from food:
- Linoleic Acid (Omega-6 fatty acid), found in veggies and nut oils.
- Alpha-linoleic acid (Omega-3 fatty acid), found in veggies, but
highest in fish and fish oils.
2) Phospholipids are:
- Composed of glycerol, two fatty acids, and phosphate
- Soluble in water!!!!!!!! Helps lipoproteins (Chylomicrons) absorb into the body! - Manufactured in our bodies so they are not required in our diet - Are critical component of cell membranes.
3) Sterols: Lipids containing multiple rings of carbon atoms
- Are essential components of cell membranes and many hormones
- Are manufactured in our bodies and therefore are not essential components of our diet
- Include cholesterol
- Fats provide 9 kcal per gram
- Much of the energy used during rest comes from rest.
- Fat- Soluble vitamins
- Vitamins A, D, E, and K are soluble in fat; fat is required for their transport.
- Enzymes in the mouth and stomach can digest only about 10 % of the fats present. - Most digestion of fats beings in the small intestine.
- As fat enters the small intestine:
- Bile is produced by the liver and stored in the gall bladder
- Bile is secreted from the gallbladder into the small intestine
- Bile disperses fat into smaller fat droplets
- Pancreatic enzymes break fat into two fatty acids and a monoglyceride
- Fatty acids are arranged as lipoproteins for absorption and transport. - Chylomicron: A lipoprotein produced by cells lining the small intestine.
- Composed of fatty acids surrounded by phospholipids and proteins
- Soluble in water (Because of phospholipids)
-Chylomicrons are absorbed by cells of the small intestine, then they:
- Travel through the lymphatic system
- Are transferred to the bloodstream
- Short-chain fatty acids are absorbed more quickly since they are not arranged into chylomicrons.
- The Acceptable Macronutrient Distribution Range (AMDR) for fat:
20-35% calories should be from fat
- The AMDR for essential fatty acids:
5-10% of energy from Linoleic acid (Omega-6, Veggie+Nuts)
0.6-1.2% of energy from Alpha-Linoleic acid (Omega-3, Fish+Fish Oil) - Recommended Dietary Allowance (RDA) of protein
- 0.8 g protein per kg body weight
- 12-20% of total energy intake should be form protein
- Cardio-vascular disease is the biggest disease killer
- Trans fatty acids:
- Can raise blood LDL levels as much as saturated fat
- Are abundant in hydrogenated vegetable oils (margarine, vegetable oil
- Should be reduced to the absolute minimum in the diet
-How to increase HDL Levels: Increase your intake of Omega-3 fatty acids. Proteins:
- Essential Amino Acids: Cannot be produced by our bodies
- Must be obtained by food
- There are 9 essential Amino Acids
-Mutual supplementation: Using two incomplete proteins together to make a complete protein - Complementary proteins: Two protein sources that together supply all nine essential amino acid
- Ex: Beans and Rice
- Example of Complete Protein: Meats, Fish, Dairy, and Eggs
- Example of Complete...
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