Download Chapter 5 – Lipids

Chapter 5 – Lipids
FUNCTIONS OF DIETARY FAT
 Energy:
calories for every gram of fat
 Food Satiety
 Supplies essential fatty acids
FUNCTIONS OF BODY FAT
 Natural oils (for skin, hair, etc)
 Thermal Insulation (controls body temperature)
 Organ protection
 Provides cell structure
 Provides energy (stored in adipose tissue)
TYPES OF LIPIDS:
1. TRIGLYCERIDES (Storage form of fatty acids in the body)
is required for triglycerides to be removed from the blood
High triglycerides can increase the risk for diabetes and pancreatitis
Normal blood range is less than 150
TO LOWER BLOOD TRIGLYCERIDES:
 decrease sugars and juices
 decrease dietary fat
 weight loss
 small meals rather than large meals
 avoid alcohol
Food triglycerides are composed of fats (solid) and oils (liquid)
2. PHOSPHOLIPIDS
 Makes up a small percentage of fat in the diet
 Act as emulsifiers both in the body and in food
 Lecithin is most common type of phospholipid, which is not an essential nutrient
3. STEROLS
 Cholesterol, vitamin D, and sex hormones
CHOLESTEROL
 can be made by the body in the liver
 Is not an essential nutrient
 Cholesterol is a precursor to all steroid hormones, helps to form bile acids, and is an
essential component of cell membranes
 ONLY found in animal products
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TYPE OF CHOLESTEROL
Total Cholesterol
HDL – cholesterol ("good" cholesterol)
LDL – cholesterol ("bad" cholesterol)
GOAL RANGE
under 200 mg/dl
Women: above 55 mg/dl
Men: above 45 mg/dl
below 100 mg/dl
TO LOWER BLOOD CHOLESTEROL:
 Reduce the amount of saturated and trans fats in the diet
 Increase good fats in the diet
 Exercise (improves HDL cholesterol)
 Small, frequent meals
 Increase dietary fiber
 Weight loss, if needed
 Prescription medications may be needed if the high
cholesterol is caused by a genetic condition
TYPES OF DIETARY FATS:
1. SATURATED FAT
 A “bad” type of fat
 Includes stearic acid
 Increases the risk for heart disease and high cholesterol
 Dietary Sources:
2. UNSATURATED FATS
 Monounsaturated Fat (“good” type)
Includes oleic acid
Can decrease risk for heart disease
Dietary Sources: olive oil, canola oil, peanut oil, nuts, olives, avocados, sesame
seeds, peanut butter

Polyunsaturated Fat
Includes linoleic acid and linolenic acid
1. Omega 6 (Linoleic Acid)
Dietary Sources: margarine, mayonnaise, vegetable oils, nuts, seeds
2. Omega 3 Fatty Acids (linolenic acid, EPA, and DHA)
Needed for normal brain development, growth and development, prevents
blood clots, and may lower risk for heart disease, hypertension, arthritis,
and cancer.
Dietary Sources: fatty fish, flaxseed, nuts, human breastmilk
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*Routine fish oil supplementation is NOT recommended for everyone (see p.161)
3. TRANS FATTY ACIDS
 Occurs when polyunsaturated oils are hydrogenated during processing, which
changes the shape of the molecules
 Increases the risk for heart disease and raises blood cholesterol
 Food Sources:
DIGESTION AND ABSORPTION OF FAT:
Most digestion occurs in the
When fat enters the small intestines, the hormone cholecystokinin (CCK) is released which
signals the gallbladder to release bile, which helps to emulsify fat for absorption.
Pancreatic lipase, an enzyme, is then sent from the pancreas to allow the emulsified fat become
absorbed.
Chylomicrons (lipoproteins) transport lipids from the intestinal cells to the rest of the body.
Lipoproteins are clusters of lipids associated with proteins that serve as transport vehicles for
lipids in the lymph and blood.
RECOMMENDED INTAKE OF FAT
20-35% of calories from total fat
Less than 10% of calories from saturated fat
Dietary cholesterol should be less than 300 mg. per day (less than 200 mg. if blood
cholesterol is high)
There are no guidelines for trans fatty acids (keep as low as possible)
To Calculate your Fat Requirements:
(
) calories needed per day (based on weight & activity)
X .20 (for 20%) =
calories from fat
(
) calories from fat ÷ 9 =
minimum grams per day
(
) calories needed per day (based on weight & activity)
X .35 (for 35%) =
calories from fat
(
) calories from fat ÷ 9 =
maximum grams per day
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