Starting from the top:
Hydrogenated oils are used in foods to increase shelf life, or to
make a thicker product (Vegetable Shortenings).
Some people can withstand them, some can't. If you have high
triglyceride reading on a blood test, or high cholesterol, you
can't abide them. Ignoring the caloric consequences, hydrogenated
and saturate fats can be mitigated by soluble fiber intake.
Soluble Fiber is found in Oats, Figs, Cocoa Fiber (powder) and many other
foods. There is no soluble fiber in meat.
I had high triglycerides - so I try to keep my intake down as much as
is possible. (3 grams per meal, allowing for snacks to take me up to
20 for the day). You also need unsaturated fats - dropping all
fats is bad for you, and you need 3 times as much unsaturated fats
as the saturate fats you consume.
In America there is no recommended amount of soluble fiber - and
finding the amount of soluble fiber in a food is nearly impossible.
So I just try to do the best I can, and use that to mitigate risk.

My wife, on the other hand, has perfect blood test readings - so
she just avoids saturated and hydrogenated fats as a source of
calories (they are the primary source of calories, besides sugar,
in most processed fast foods).

Good Luck.