The Lipids

The Lipids

Fats, Oils, Phospholipids, and Sterols

Terms:

lipid

cholesterol

fats

oils

fatty acids

Fats

triglycerides

phospholipids

lecithin

sterols

Usefulness of Fats

provide energy reserves

lend satiety to meals

enhance food’s aroma and flavor

cushion the vital organs

protect body from temp. extremes

carry fat soluble nutrients

serve as raw materials

material to make cell membranes

Essential fatty acids

fatty acids needed by the body but not made by the body in amounts sufficient to meet physiological need

Harmful potential of fats

CVD

Two kinds of lipids

In foods: triglycerides cholesterol

In the blood: blood triglycerides blood cholesterol

Triglycerides

Fatty acids and glycerol

Saturated vs Unsaturated Fatty Acids

saturated fatty acid

point of unsatuation

unsaturated fatty acid

monounsaturated fatty acid

polyunsaturated fatty acid

monounsaturated fats

polyunsaturated fats

Other members of the lipid family

Phospholipids

Sterols

Other terms: emulsifier bile

Lipids in the body

Digestion of fats

mouth

stomach

small intestine - bile monoglycerides chylomicrons lipoproteins

Lipid transport in the body fluids

LDL - low density lipoproteins

HDL - high density lipoproteins

Significance of LDL and HDL - p. 142

Rules of thumb:

A minimum of 35 mg. HDL/deciliter of plasma is associated with low risk

Total blood cholesterol should be no more than about four times higher than HDL cholesterol

How can I burn my stored fat?

Excess fat is carried by LDL to cells, stored.

When glycogen stores run out, fat cells dismantle stored fat.

Fat fragments + a glucose fragment continue release of energy.

Fat goes through fewer chemical steps before storage than glucose does, so you may get fatter on fat calories than on the same number of carbohydrate calories.

Essential Polyunsaturated Fatty Acids

linoleic acid

linolenic acid

deficiency

reproductive failure, skin abnormalities, kidney and liver disorder

omega-6 fatty acid

omega-3 fatty acid

EPA, DHA

Fish Oil Supplements

free radical

antioxidant

Hydrogenation & Emulsification

hydrogenation

smoking point

trans-fatty acids

emulsification

Trans-fatty acid

During hydrogenation of polyunsaturated oils, some unsat. fatty acids end up as trans-fatty acids.

These may elevate LDL cholesterol and lower beneficial HDL.

May also play a role in promoting or causing cancer.

What foods should you avoid?

Consumer Corner - Fat replacers

Must contribute little food energy, be nontoxic, not be able to be stored in body tissues, and not rob the body of needed nutrients.

Simplesse - protein based

Olestra - a sucrose polyester digestive problems nutrient and other losses

Added fats

oil or shortening

mayonnaise, butter, margarine

salad dressing, cream cheese, heavy cream

sour cream

Fats in meat

very lean

lean

medium-fat

high-fat

"percent fat free"

Milk, yogurt, and cheese group

whole milk

nonfat

Bread, cereal, rice, and pasta

fats can be well hidden

Fruits and vegetables

zero, nada, zippo

Defensive dining

Eliminate fat as a seasoning and in cooking

Cut down on intake of red meat

Remove the fat from high-fat foods

Replace high-fat foods with low-fat versions or naturally occurring low-fat alternatives

Tips to update high-fat recipes

Don’t fry

Add water or nonfat yogurt to salad dressings and apply sparingly

Reduce meat and substitute shredded vegetables, legumes, pasta, grains, etc.

Trim all visible fat and skin

Refrigerate broth and remove fat

Make mixes without the fat called for

When dining at fast food places

Green salads are a good choice and use about a quarter of the dressing

Order a small hamburger, no mayo, or chili or a plain baked potato

Broiled sandwiches without spreads, dressings, cheese, bacon, or mayo are also good choices