fats and fat-related compounds such as cholesterol, lipoproteins, and phospholipids
building blocks or structural components of fats
cells and tissues that store fat
a sterol normally found in bile (contributes to gallstones), synthesized by the liver and is a precursor of various steroid hormones, such as estrogen, and testosterone, and of the vitamin D molecule produced by the action of UV light on the skin. found in animal tissues such as meat, egg yolk, and milk fat
comes from two oil plants (coconut oil and palm kernal oil) all others come from animal origin (meat, butter, and whole milk dairy products
major carriers of lipids in the plasma, combination of fat surrounded by protein makes possible the transport of fatty substances in a water medium such as plasma
carbon-based chemical compounds
a neutral fat synthesized from carbohydrate and stored in adipose tissue, it releases free fatty acids into the blood when needed for energy
essential fatty acid for humans; an n-6 polyunsaturated fatty acid
essential fatty acid for human; an n-3 polyunsaturated fatty acid
essential fatty acids
must be supplied in diet b/c the body can't make them or can't make in sufficient amounts
n-3 polunsaturated fatty acid synthesized by the body in limited amounts from a-linolenic acid and can be obtained from fish oil, helps lower the risk of heart attack or stroke
n-3 polyunsaturated fatty acid synthesized by the body obtained from fish oil: important for brain and neural development in infants and helps lower the risk of heart attack or stroke
Health concerns r/t dietary fat focus on which two issues?
1.) the high energy content of fat 2.) the negative effects of certain fatty acids.
Which fats have positive effects on the body?
polyunsaturated and monosaturated
Which fats add to health risks?
Saturated and Trans fats
Where are saturated fats and cholesterol found?
saturated found primarily in animal sources, cholesterol found only in animal foods
Where are unsaturated fats found?
vegetable oils and fatty fish
Where are trans fats found?
produced in the commercial processing of lipids (best if eliminated from diet, very bad)
What are the functions of food lipids? (5)
1. Provide energy (9kcal/g),2. supply essential fatty acids, 3.support absorption of fat soluble vitamins (DEAK), 4.add to food palatability (flavor) 5. promote satiety
What are the essential tasks performed by adipose tissue? (7)
1. storage source of energy 2. thermal insulation 3. protection of vital organs 4. transmission of nerve impulses 5. form membrane structure 6. carrier of fat-soluble materials (lipoproteins) 7. precursor of other substances (brain tissue and retina)
Give examples of polyunsaturated and monosaturated fats.
mono, generally from plant sources (canola and olive oil)
poly, plant sources often used in cooking (corn, safflower and vegetable oils)
What roles do the essential fatty acids play in our body? (7)
1. skin integrity 2.regulation of blood cholesterol 3. gene expression 4. immune function 5. aggregation of blood platelets 6. synthesis of hormone-like agents
What are the adequate Intake (AI)s of the two essential fatty acids? women, men
For linoleic acid: 17g/day for men and 12g/day for women ages 19-50 yrs. over 51, 14g/day for men and 11g/day for women. For a-linoleic acid: 1.6g/day all adult men and 1.1g/day for all women
What role does arachidonic acid and docosahexaenoic acid play in infant development (both found in breastmilk)
ensure brain and neural development
What are the best sources of the two essential fatty acids?
vegetable oils: corn oil, safflower oil, soybean oil, cottonseed oil, sunflower oil and peanut oil all contain linoleic acid. a-linolenic acid found in canola oil, linseed oil, rapeseed oil, and dark-green leafy vegetables.
What happens when inappropriate high intakes of fish oil supplements are consumed?
excessive bleeding and interfere w/ other aspects of fatty acid metabolism
How does the body store fatty acids?
in the form of triglycerides made from three fatty acids attached to a glycerol base.
Where are glycerides found?
food and also formed in the body (most natural lipids from animal or plant sources are triglycerides).
process used to produce margarine and shortening from vegetable oils are exposed to hydrogen atoms are added at many of the double bonds of the polyunsaturated fatty acids, forming a solid fat.
What are some major sources of hidden fats?
bakery items such as cakes, muffins, cookies, crackers and even frozen entrees such as lasagna
What are the Acceptable Macronutrient Distribution Range (AMDR) for fat?
20% to 35% of total kcalories
What are the roles cholesterol plays for normal body function? 4
1. precursor to steroid hormones (estrogen and testosterone), 2.formation of bile acids 3. component of brain and nerve tissue 4. component of cell membranes
What are the food sources of cholesterol?
only in animal foods: egg yolk, meat, whole milk, cheese, and organ meats
How much does the American Heart Association recommend?
300 mg/day or less
How do lipoproteins function in the body?
liver is the body's clearinghouse for fatty acids and cholesterol (supplied or produced in body tissues), when they are received by the liver they are packaged into lipoproteins and then released into the circulation for transport to cells.
How are lipids transported?
compounds called phospolipids located in the cell membranes help lipid molecules move from the circulatory system into the cell.
What are the 5 classes of lipoproteins?
Chylomicrons, Very low-density lipoproteins (VLDLs), Intermediate-density lipoproteins (IDLs), LDLs , HDLs
Where and what begins the process of lipid digestion?
Mouth, with lipase from the salivary secretions
What is the only gastric secretion specific to lipids?
enzyme gastric lipase (tributyrinase), which acts on emulsified butterfat.
What are the 3 sources for lipid breakdown in the small intestine?
1.)Bile from the liver and gallbladder: presence of fat releases CCK, which causes gallbladder to contract releasing bile ,2. enzymes from the pancreas: pancreatic lypase breaks off the fatty chains, 3. enzyme fro the small intestine: Lecithinase acts on lecithin a phospholipid!