How trans fat harms you

Doctors worry about added trans fat because it increases the risk for heart attacks, stroke and type 2 diabetes. Trans fat also has an unhealthy effect on your cholesterol levels.

There are two main types of cholesterol:

• Low-density lipoprotein. LDL, or "bad," cholesterol can build up in the walls of your arteries, making them hard and narrow.
• High-density lipoprotein. HDL, or "good," cholesterol picks up excess cholesterol and takes it back to your liver.

Trans fat increases your LDL cholesterol and decreases your HDL cholesterol.

If the fatty deposits within your arteries tear or rupture, a blood clot may form and block blood flow to a part of your heart, causing a heart attack; or to a part of your brain, causing a stroke.