For years, saturated fats have been deemed the bad guys in increasing heart disease. More recently, trans-fatty acids joined saturated fat on the heart-healthy "do not eat" list.

Trans fats are formed when liquid oils (such as soybean or safflower oil) are partially hydrogenated to make them more solid at room temperature. Trans-fatty acids are now listed on food labels. To simplify label reading and finding heart-friendly foods, add up the grams of trans fat and saturated fat combined -- the bad fats -- and choose foods with the lowest value.

If you find foods that don't list trans-fatty acids, choose those with the lowest amount of saturated fat and in which partially hydrogenated oil is not the first ingredient.

Test your knowledge about trans and saturated fats!

1. Which has less trans fat?

1. a. A McDonald's hamburger
2. b. Three-piece Chicken Select from McDonald's

Correct answer: b. Three-piece Chicken Select

The hamburger has 0.5 g of trans fat, but the Chicken Select no longer has any. Both have the same amount of saturated fat, 3.5 g.

Which fast-food salad is the best for you?

1. Wendy's Mandarin Chicken Salad
2. McDonald's Caesar Salad with Grilled Chicken
3. Burger King Tendergrill Chicken Garden Salad

Correct answer: a. Wendy's Mandarin Chicken Salad

Wendy's has no trans fat and 0.5g of saturated fat, 3 g of saturated fat if you include the dressing and crispy noodles. The McDonald's salad has 0 g of trans fat and 3g of saturated fat, with up to 6.5 g of saturated fat including the Caesar dressing. Burger King's salad has 0 g of trans fat and 3.5 g of saturated fat. Its salad dressings have no trans fat, but their saturated fats range from 0 g (fat-free ranch, a "restaurant option") to 4 g (creamy Caesar).