A mostly man-made form of fat used by food manufacturers to increase flavor lengthen the shelf-life of foods.  Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels. Eating trans fats increases your risk of developing heart disease and stroke. It’s also associated with a higher risk of developing type 2 diabetes. (AHA)

Additional Resources:

http://www.americanheart.org/presenter.jhtml?identifier=3045792

http://www.mayoclinic.com/health/trans-fat/CL00032

http://www.hsph.harvard.edu/nutritionsource/nutrition-news/transfats/index.html