Fats, also known as "lipids," are one of the three types of nutrients used by the body for energy. The energy produced by fats is 9 calories per gram. Proteins and carbohydrates each provide 4 calories per gram. Therefore, fat has more than twice as many calories as proteins and carbohydrates weight for weight.

Fats are basically long compounds formed from chemicals called "fatty acids." These fats get broken down into fatty acids in the digestive system. It is the type of fat in your diet that affects your risk for heart disease. There are bad fats that increase the risk for certain diseases and good fats that lower this risk.

Fat is made up of saturated, trans fats, monounsaturated and polyunsaturated fats.

While saturated fats raise total blood cholesterol levels more than dietary cholesterol does; they tend to raise both the "good" HDL (high-density lipids) and the "bad" LDL (low-density lipids) cholesterol.

Saturated fats are associated with an increased risk of heart disease. However, monounsaturated and polyunsaturated fats can help to reduce blood cholesterol levels.

These fats are associated also with an increased risk of heart disease. Trans fatty acids are fats produced by heating liquid vegetable oils in the presence of hydrogen. This process is known as hydrogenation. The more hydrogenated an oil is, the harder it will be at room temperature. A tub of soft margarine is less hydrogenated and has fewer trans fats than hard stick margarine. Trans fats are worse for cholesterol levels than saturated fats because they not only raise LDL (bad) cholesterol, but also lower HDL (good) cholesterol.

Trans fats are found in commercially prepared fried and baked goods, margarine, snack foods, and processed foods. Even though some trans fats naturally occur in animal products, the majority of these dangerous fats are man-made. The U.S. Department of Agriculture states that these hydrogenated oils or "partially hydrogenated oils" as they are listed on ingredient labels, can be found in about 40 percent of grocery store foods, around 40,000 products, including products that most consumers assume are healthy.

Because trans fat is not easily found on food labels, often foods that claim to be low in saturated fat, saturated fat free, cholesterol-free or made with 100 percent vegetable oil, can contain so much trans fat that we probably wouldn't even purchase them. That is if we knew what to look for. Some foods do list trans fat on their labels; a practice that all food and dietary supplement manufacturers must comply with by January 1, 2006.

It is almost impossible to avoid trans fat, but reducing your intake to the smallest amount possible should be your goal. Here are a few ways to be on the lookout for trans fat on labels:

• You should expect trans fat to be in spreads, margarines, shortenings, snack foods, crackers, commercial baked good, bakery mixes, sauces, some energy/protein bars, instant soups, breaded frozen foods and frozen entrees.


• Look for the words hydrogenated, partially hydrogenated or fractionated in the ingredients. The closer these ingredients are at the top of the list, the larger amount of trans fat the product has.
  [Reading Food Labels]

Cholesterol, which is made in the liver and linked to carrier proteins called lipoproteins, plays an important role in the formation of cell membranes, some hormones and vitamin D. These lipoproteins dissolve in the blood and enable the fatty acids to be transported to all parts of the body. Cholesterol at low levels is necessary for normal function of the body, however high blood cholesterol levels greatly increase the risk for heart disease.

Surprisingly, the amount of cholesterol in food is not strongly linked to cholesterol levels in the blood. The biggest influence on blood cholesterol levels is the mix of fats in the diet. Regular consumption of 'good fats' offsets the effect of the 'bad fats'.

Low-density lipoproteins (LDL) carry cholesterol from the liver to the rest of the body. When there is too much LDL cholesterol in the blood, deposits of cholesterol can build up inside arteries. These deposits can narrow an artery enough to slow or block blood flow. This narrowing process, called atherosclerosis, commonly occurs in arteries that supply the heart (the coronary arteries). When any part of the heart muscle (yes, the heart is a muscle) fails to get blood and oxygen, the result may be chest pain known as angina. The good news is that the buildup of cholesterol can be slowed, stopped and possibly even reversed!

High-density lipoproteins (HDL) carry cholesterol from the blood back to the liver, which processes the cholesterol for elimination from the body. HDL makes it less likely that excess cholesterol in the blood will be deposited in the coronary arteries, which is why HDL cholesterol is often referred to as the "good" cholesterol.

For adults 20 years or over, the most recent federal guidelines from the National Cholesterol Education Program recommend the following target levels:

1. Total cholesterol less than 200 milligrams per deciliter (mg/dl)
2. HDL cholesterol levels greater than 40 mg/dl
3. LDL cholesterol levels less than 100 mg/dl

Unsaturated fats are usually found in products derived from plant sources, such as vegetable oils, nuts, seeds and some fish. In studies in which polyunsaturated and monounsaturated fats were eaten instead of carbohydrates, these good fats decreased LDL levels and increased HDL levels.

• Substitute good fats for bad fats.
• Use liquid vegetable oils or a soft tub margarine that is labeled trans fat free or non-hydrogenated.
• If you use soft margarine, be sure that it's also low in saturated fat.
• Reduce intake of commercially prepared baked goods, snack foods and processed foods, including fast foods.
• When foods containing hydrogenated or partially hydrogenated oils can't be avoided, choose products that list the hydrogenated oils near the end of the ingredient list.

For many years, margarine was considered to be a healthy alternative to butter. This assumption was made because margarine contained unsaturated vegetable oils and therefore was thought to be better for the heart. Research has since concluded that some forms of margarine, especially hard stick margarine, are actually worse for the heart than butter. This is because they contained large amounts of trans fats.