Trans fats, but not saturated fats like butter, linked to greater risk of early death and heart disease

Contrary to prevailing dietary advice, a recent evidence review found no excess cardiovascular risk associated with intake of saturated fat. In contrast, research suggests that industrial trans fats may increase the risk of coronary heart disease.

Originally created to enhance flavor, extend shelf life and improve texture, these fats are present in a myriad of foods that many people eat on a daily basis.

Don't eat any product which has the words "partially hydrogenated" or "shortening" in the ingredients list.

You should look for trans fats in any of these products:

Cookies
Crackers
Cakes
Muffins
Pie crusts
Pizza dough
Margarine
Vegetable shortening
Cake mixes
Pancake mixes
Chocolate drink mixes
Donuts
French fries
Potato chips
Candy
Packaged popcorn
Frozen dinners
Salad Dressings
Deep Fried Foods

Source: http://www.sciencedaily.com/releases/2015/08/150811215545.htm