Trans fat is formed when vegetable oils are hardened into margarine or shortening.

It is my impression that saturated fat has taken most of the bad rap for trans fat. Most of the studies that attribute negative health consequences from consuming saturated fat actually never controlled for trans fat.

So let's get things straight: trans fat -- not saturated fat -- is the one you need to avoid at all costs.

Many food companies use trans fat instead of oil because it reduces cost, extends storage life of products and can improve perceived flavor and texture. These fats have only been around for the last 100 years, yet are found in thousands of processed foods. It is one of the worst "foods" that you can put in your body and should be rigidly avoided at all costs.

It's no secret the trans fats -- present in processed foods ranging from Girl Scout cookies to McDonald's French fries -- harm your health. So, it shouldn't surprise you to learn trans fats likely contribute more to a patient's weight gain than any other kind of fat.

In fact, trans fats lead to a major increase in cancers, arthritis, fatigue and nearly all chronic illnesses. Trans fats are also an enormous instigator of diabetes, which is dramatically increasing. As was mentioned in the article, trans fat is known to increase blood levels of low-density lipoprotein (LDL), or "bad" cholesterol, while lowering levels of high-density lipoprotein (HDL), known as "good" cholesterol. It can also cause your arteries to clog.

No wonder more U.S. health experts are calling for a complete nationwide ban on trans fats, something that's apparently very doable in some parts of the world.

If you want to review a good primer on trans fat, you should read "Trans-Fat: What Exactly is it, and Why is it so Dangerous?"