Tony, margerine can be full of trans fats due to the hydrogenation that turns the vegetable oil into a solid. It changes the molecules. That's how trans fats are made. My Harvard book said the same thing.
http://en.wikipedia.org/wiki/Margarine
I'm not worried about the weight gain. I struggle keeping the weight on at this point. Now at over 6 months of consistency in my diet and excercise, my metabolism is off the charts. My pallet has changed. I grew up in Iowa so naturally, the midwestern diet was in my blood. Today, I really prefer Salmon and a really good salad(7-10 veggies) over a steak and baked potato. Polish dinner off with a papaya and some blueberries.
That being said, I still crave a hamburger or steak. With my B12 deficiency, it's important for a balanced diet anyway. Since B12 is stored for 2-5 years in the liver, I can't blame my recent nutrition since I've always ate plenty of red meat.