Fat: It Does Your Body Good
But How Much, What Kind, and Which Ones Should You Avoid?
Denis Faye breaks it down

Fat: In the good old days, it seemed like all you needed to know about fat was that fat makes you fat, so eat less fat. That was about it.

But then you started to read more, to keep abreast of health trends. Terms popped up like trans fat, saturated fat, omega-3s and cholesterol. Now, one day the headlines say fat is a killer, but the next day, they insist it is crucial to human existence. What's a healthy eater to do?

Happily, it's not as confusing as it seems. Fat is a vital part of all diets that, like anything else, needs to be consumed in moderation. So let's break it down a little, learn a few needlessly big words, and take a crack at understanding fat.

The good side of fat: Like carbohydrates, fat is fuel for the body, especially useful for long-term aerobic exercise. It helps with the digestion of fat-soluble vitamins A, D, E and K and it promotes a feeling of fullness after eating.

It plays an important part in the production of prostaglandins, hormone-like compounds that regulate blood pressure, heart rate, blood vessel constriction, blood clotting and the nervous system.

Fat also provides essential fatty acids, in particular omega-3, which is found in several fats and oils, mainly fish, soy and flax seed. The various omega-3 fatty acids help us with brain development, nervous system function and eyesight. Many experts also believe they reduce the risk of arthritis, some cancer, high blood pressure, and heart disease.

The bad side of fat: But all those benefits don't mean hourly olive oil shooters would be a good idea. As is the case with proteins and carbs, eating fat requires a little restraint. About 20-30% of your calories should be from fat, otherwise, you open yourself up to a world of hurt.

Keeping in mind that a gram of fat is 9 calories, as opposed to 4 calories in a gram of protein or carbohydrates, you should be eating about half as much. And fatty foods tend to be dense, so a little goes a long way. Too much fat can lead to heart disease and diabetes. Fat can also, well, make you fat. This, in turn, can lead to various complications including liver disease and diabetes.

And then there's the matter of cholesterol: Often vilified, cholesterol is actually important to the human body. It's important in the creation and maintenance of cell membranes, the creation of sex hormones, the production of bile salts and, combined with sunlight, it creates vitamin D.

But before considering butter as a health food, remember that our body creates all the cholesterol it needs. So eating a lot of it only clogs in your arteries, increasing your risk of heart attack.

Cholesterol is transported through your system by proteins called apoproteins. Combined, cholesterol and apoproteins are called lipoproteins. Lipoproteins that are low in cholesterol, or low-density lipoproteins (LDL) are often referred to as "bad cholesterol" because they clog up your arteries. High-density lipoproteins (HDL) are believed to clean LDLs out of your arteries and are therefore referred to as "good cholesterol."

So the trick is to keep the LDLs to a minimum. We do this by keeping an eye on the fats we eat.

Types of fat

Monounsaturated Fat -- are about as good as it gets. Full of HDLs, they can actually help prevent heart disease by flushing out your system. Monounsaturated fats are also more resistant to oxidation, something that leads to cell and tissue damage.

You'll find monounsaturated fats in olives and olive oils, peanuts, canola oil, avocados and many nuts.

Polyunsaturated Fat -- here's where you find your omega-3s with all their aforementioned benefits. They're also packed with HDLs, although they are more prone to oxidation, or the breaking down of cells. Many vegetable oils, including safflower, sunflower and soy, are polyunsaturated. As previously mentioned, fish are a good source, too. But be careful, some seafood, particularly shrimp, is loaded with cholesterol -- not fat, but pure cholesterol, which isn't generally a good idea.

Saturated Fat -- now we're dipping into "bad" fat territory. For the most part, these fats are loaded with LDLs, meaning too much of the stuff will send your cholesterol levels soaring. You'll find plenty of saturated fat in red meat, poultry (especially dark meat), whole dairy products and tropic oils such as coconut oil.

Trans Fat -- the new kid on the block. Processed food manufacturers discovered that if you hydrogenate polyunsaturated vegetable oils, they'd become more solid and spoil later. Today, they are used in most commercial baked goods -- cookies, crackers, donuts, pie, cake, as well as shortenings, candy, and many margarines. Unfortunately, it was later discovered that trans fats are just as bad for you as saturated fats, if not worse. They raise your cholesterol levels and one study actually shows that they lower your omega-3 levels.

In July of this year, the FDA issued a regulation that manufacturers must list trans fats on their nutritional labels by 2006. Some manufacturers have already started.

Most of the packaged foods we eat contain more than one type of fat. That's why reading these labels is so important, so do it! Keep your saturated and trans fats down. Sure, it's a little complicated at times, but keep an eye on them now and soon you'll find yourself not-so-fat, but definitely happy!