Trans fats were invented in a laboratory to be a healthy alternative to artery-clogging saturated fats. But in a classic case of consumer science gone awry, trans fats are now estimated to cause 50,000 deaths a year by promoting heart disease and cancer as well as dementia and diabetes. Trans fats also hike up dangerous blood chemicals like triglycerides and lipoprotein (a), depress levels of "good guy" HDL cholesterol and even make cells more resistant to insulin — a step toward diabetes. Here are some easy ways to avoid bad fats.