Many people are aware that trans fat is considered by many doctors to be the worst type of fat because it delivers a double-whammy by raising your "bad" (LDL) cholesterol and lowering your "good" (HDL) cholesterol at the same time. The combination of a high LDL cholesterol level along with a low HDL cholesterol level increases the risk of heart disease, one of today’s leading killers of both men and women. This fact alone means that all trans fat should probably be avoided by everyone interested in maintaining good health.
Trans fat used to be more common in American foods, but because of concerns over the health effects most food manufacturers are now using far less of it even though the use of trans fats in the manufacturing of foods helps them stay fresh longer and have a longer shelf life. These properties make the oil less likely to spoil because trans fat is created by adding hydrogen to vegetable oil through a process called hydrogenation. Trans fat may help the manufacturers, but it isn’t doing human bodies any good at all because the addition of hydrogen to vegetable oil increases blood cholesterol levels far more than do most other types of fats and the addition of hydrogen also makes those oils more difficult to digest. Many commercially produced baked goods and many fried foods can contain trans fats and some shortenings and margarines tend to be especially high in trans fat. Thankfully, food manufacturers in the United States and other countries now list the trans fat content on nutrition labels, making them easier to avoid, but it can get tricky when the manufacturers refer to "partially hydrogenated" vegetable oils because that's just another term for trans fat.
Although it may sounds contradicting, foods containing "fully" or "completely" hydrogenated oils do not actually contain trans fat. Unlike the partially hydrogenated oils, the process used to make fully or completely hydrogenated oil does not result in the creation of trans-fats. But be aware that if a food label states only the use of "hydrogenated" vegetable oil, it could mean the oil actually contains some trans fat.
The actual amount of trans fat you can safely consume is currently unknown, but both the Food and Drug Administration and the American Heart Association advise limiting your intake whenever possible. This does not mean that any food that is free of trans fat is good for you though, as food manufacturers often substitute other ingredients for trans fat like coconut and palm oils that contain a lot of saturated fat on their own. A healthy diet does include some fat, and one quarter of your daily calories can come from fat, but to be safe saturated fats should only account for less than 10 percent of your total daily calories. People diagnosed with high levels of LDL cholesterol should try to limit their intake to consuming less than 7 percent of their fat calories in the form of saturated fat. The only good news about trans fat is that it is showing up less on the grocery store shelves these days, however many restaurants still use trans fats in the oils they use to fry food and you could end up eating too much of it if you eat out a lot.