at facts can be very slippery, but they're important to understand. When you have a handle on your fats, it's much easier to make healthy food choices that can, in turn, reduce your risk of heart disease, stroke and certain cancers.

I've put together a glossary of terms and foods that are important in the world of fats. I know that there are lots of terms that sound the same, so be patient and try to understand rather than memorize their importance. Let me start with a diagram of how the important fats relate to each other.

Lipids:

The scientific name for all the fats and fat-like substances found both in the body and in food. One element that all lipids have in common is that they do not dissolve in water.

Triglycerides:

The common form of fat that is found in food and in the body. Most of the fats I will describe are made up of triglycerides. Most of our body fat is stored as triglycerides. When circulating in the blood, they encourage LDL cholesterol production.

Cholesterol:

A waxy fat-like substance that is found in each of our cells and in foods from animal origins. It is produced by the liver and is essential for the production of hormones, new cells, vitamin D, and bile acids (for fat digestion). Eating cholesterol is not believed to have very much effect on blood cholesterol levels or cholesterol production. Cholesterol in food is not the same as the cholesterol in our blood.

LDL Cholesterol:

Considered the "bad" cholesterol that circulates in our blood. LDLs carry cholesterol and other lipids to all cells in the body and deposit them there. However, the LDLs can also deposit the fats on artery and vessel walls where they harden and form plaque, resulting in the arterial disease atherosclerosis. LDL cholesterol below 100mg/dl is optimal.

HDL Cholesterol:

Considered the "good" cholesterol. HDLs circulate in the blood, pick up cholesterol and fats in the cells, and carry them back to the liver to be broken down and excreted from the body. HDL cholesterol greater than 60 mg/dl is desirable.

Fat:

Group of lipids in foods and our bodies that are made mainly of different combinations of triglycerides. Fats, like protein and carbohydrates, contribute calories to our diets. Fat that is stored in the body is called adipose tissue.

Saturated Fats:

The chemical name for a fat that is holding all the hydrogen atoms it can possibly hold. The term "saturated" refers to the fact that a fat is saturated with hydrogens. Saturated fat is in some of the foods we eat. Once ingested, it stimulates the liver to produce LDL cholesterol. See chart below for sources of saturated fats.

Hydrogenated Fats:

These are manmade saturated fats. They start out as unsaturated fats (usually polyunsaturated vegetable oils) that are processed with hydrogen to make them saturated and solid. Most processed foods contain this type of fat because it is very cheap to produce and use and it keeps the product fresher for longer. Hydrogenated fats are considered worse than saturated fats because they raise LDL and lower HDL cholesterol levels. See chart below for sources of hydrogenated fats.

Trans Fatty Acids:

Also called trans fats, these fats are formed in the process of hydrogenation. The polyunsaturated fats that are left over get twisted and their functions change. They also cause LDL production to increase.

Unsaturated fats:

Fats that are missing at least one hydrogen pair from their structure.

Monounsaturated Fatty Acids (MUFAs):

Only one hydrogen pair is missing from this fat. It is a healthy fat because it helps lower LDL and raise HDL production, lowering the risk of heart disease and strokes. See chart below for sources of MUFAs.

Polyunsaturated Fatty Acids (PUFAs):

Two or more hydrogen pairs are missing from this fat chain. There are only two essential fats that we require and they are both PUFAs. These fats lower both LDL and HDL cholesterol, and since they are so prevalent in the form of vegetable oils and margarine spreads, many experts believe they are too abundant in our diets. One other point of caution about PUFAs is that they react easily with oxygen (oxidation) and turn rancid easily. Oxidized oils could promote inflammation, cancer, arterial damage, degenerative diseases, and premature aging. Omega-3s and Omega-6s are both polyunsaturated.

Omega-3 Fatty Acids:

A highly unsaturated polyunsaturated fat. Most Americans are believed to be deficient in this beneficial fat that may help prevent atherosclerosis and reduce blood clotting. They are also helpful for lowering triglycerides and LDL cholesterol. Unlike most polyunsaturates, this type of fat does not affect HDL levels. See chart below for sources of omega-3s.

Omega-6 Fatty Acids:

A polyunsaturated fat. Like saturated fat, this fat is quite common in our diets because it is in vegetable oils, nuts, and meats. Omega-6 fats lower both LDL and HDL cholesterol. In the body they tend to compete with Omega-3s for a limited supply of enzymes, and the Omega-6s usually grab the most enzymes since they have the largest army. This basically prevents the omega-3s from doing their job. Omega-6 fats should not be avoided altogether, but we should all make an effort to limit omega-6 fats and favor omega-3s. See chart below for sources of omega-6s.

Sources of Saturated Fats Butter Coconut Oil Palm kernel oil Fatty beef Fatty pork Poultry skin Full fat dairly products Cheese

Sources of Hydrogenated Fats Cookies Crackers Pastries Fried Foods Margarine Shortening Chips

Sources of Omega-6 Fats Corn oil Cottonseed oil Sunflower oil Sesame oil Soybean oil Peanut oil Meat Poultry

Sources of Monounsaturated Fats Olive oil Canola oil Flax Seed oil Almonds Cashews Pistachios Macadamias Avocados

Sources of Omega-3 Fats Salmon Tuna Herring Mackerel Sardines Walnuts Pumpkin seeds Soybeans Soy products