You should avoid trans fats as much as possible. They're bad for your heart health.
Trans fats raise LDL "bad" cholesterol and make you more likely to get heart disease. They also lower HDL "good" cholesterol.
Based on a review of the scientific evidence, the FDA no longer recognizes trans fat that comes from partially hydrogenated oils as GRAS (generally recognized as safe). The trans fat ban doesn't affect the small amounts of natural trans fats found in beef, lamb, and full-fat dairy products.
Food makers once used artificial trans fats to enhance the flavor, texture, and shelf life of processed foods. You might have seen those trans fats listed as "partially hydrogenated oils."
What to Check
Check the Nutrition Facts label and the ingredient list. If the Nutrition Facts label says the product has "0 g trans fat," that doesn't necessarily mean it has no trans fats. It could have up to half a gram of trans fats per serving. So check the ingredient label to see if "partially hydrogenated oils" is on the list. Those are trans fats.