Consumption of dietary trans fats is associated with irritability and aggression according to an article posted in the Public Library of Science Online in April of 2012. Trans fats are never saturated. If they are fully hydrogenated, they are no longer trans fats; they become saturated fat. Natural trans fats made in nature, such as vaccenic acid (found in meat and dairy) actually lower LDL cholesterol and triglycerides. While the FDA bans the use of trans fats in our food, what they call "zero" trans fat actually has up to one gram of trans per tablespoon, or up to 7% of the food in question. Keep in mind that just 3.5 grams of trans fat causes the aggressive changes mentioned in the study presented!