Googling FDA and trans-fats: Trans Fat
The FDA considers trans-fats as no longer "generally recognized as safe."
The FDA moves pretty slowly and is influenced by industry, but they ARE targeting the unhealthful ingredients in fast-food. THat doesn't mean that all fast-food is unhealthy. Just a lot of it.
Trans-fats are used in fast-food to fry things. A lot of fast-food is fried. Have you ever worked in a fast-food restaurant that had a deep fat frier? I did. The boss changed the oil once a week. He'd pour these heavy 5 gallon jugs into the friers. I don't even remember how many jugs it took. That shit was heavily oxidized. The only thing that kept it edible for so damn long was being partially hydrogenated. That's trans-fat.
To tell the restaurant industry they now have to use lard (which the public would reject but would allow restaurants to change the oil infrequently) or use non-trans fat oils (which would require them to change the oil more frequently) would cost the restaurant industry a lot of money. So they hem and haw to buy time for the restaurant industry to accept their fate.
Female, 5'3", 50, Max squat: 202.5lbs. Max deadlift: 225 x 3.