Since you are having problems with gall stones (haven't had your gall bladder removed) then you should stick to things like virgin olive oil and margarine (very sparingly) on toast, sandwiches, etc. If you use low-fat mayonnaise on your sandwiches YOU DON'T NEED MARGARINE! Read those labels and see what the fat content is. I had my gall bladder out and my doctor told me to completely stay away from fats! I was feeling terrible and by accident I was talking to one of my friend's daughters who had her gall bladder out the year before and her doctor told her to introduce Olive Oil, margarine and stay away from Trans Fats. I decided to take her advice and felt much better. We all need a bit of good fats in our diet. Go onto: www.google.com Type in: Low-fat diets Hope you're feeling better soon.