Uhm, not quite.
Beef tallow gives fried food it's yummy taste, and that's what McD, KFC, BK, etc. all used before Center for Science in the Public Interest (CSPI) became the National food nannies.
In 1984, CSPI kicked off their anti-saturated fat campaign, blaming McD, KFC, BK, Wendy's, et al for clogging our arteries with evil saturated fat. *shudder*
Instead of telling the vegetarians CSPI to go piss up a rope, the fast food joints switched to vegetable oil for frying.
Now, the edible oil industry knew that un-saturated fats (oils) breakdown and go rancid much faster than saturated fats like tallow and lard, ... so they bind a hydrogen atom to the fat chain, producing a hydrogenated or trans fat.
The Tragic Legacy of Center for Science in the Public Interest