Trans fats have become a topic of many conversations in recent years as research has discovered their negative affects. According to WebMD:
Trans fats seemed like such a good thing once, enhancing the flavor, texture, and shelf life of many processed foods -- from cookies to frozen pizza. Unfortunately, they come with a health risk. Trans fatty foods tantalize your taste buds, then travel through your digestive system to your arteries, where they turn to sludge. . . Like saturated fats, trans fats raise LDL "bad" cholesterol and increase the risk of heart disease. But unlike saturated fats, trans fats lower HDL "good" cholesterol.
So, does that "sludge" stay in your body forever? Dr. Susan Mitchell says in an article she wrote for ThirdAge, "Trans fat isn't stored as trans fat in the body but broken down into components such as triglycerides".
This seems to be confirmed by a post on Mad Sci Network by Michael Onken, a biochemist at Washington University in St. Louis, who references "Helena Curtis' introductory textbook, Biology". It is somewhat of a technical description, so scientists feel free to follow the link for the full post. The basics are:
* Fat cells store triglycerides in large containers that take most of the cell.
* The cells grow as they fill up on triglycerides, leading to the increase in size we see.
* The weight is lost by breaking down the triglycerides into a fatty acid.
* Which is then used to create energy and releases carbon dioxide (don't tell Al Gore, he might outlaw fat people...).
So, basically trans fats get processed just like any other fat. If a person consumes large amounts and doesn't exercise, then the fats could potentially not get processed, but this is true for all fats. The real reason trans fats are so bad is because they raise the bad cholesterol and lower the good cholesterol.
The American Heart Association recommends "that about 25–35 percent of your daily calories come from fats. Less than 7 percent of calories from saturated fat and less than 1 percent from trans fat is recommended." Taking a typical 2000 calorie diet that means about 500 or so calories should come from fats, but only 20 calories should come from trans fats. Most of your fat calories should come from monounsaturated and polyunsaturated fats.