Why is margarine bad? I used butter for awhile after hearing the term "plastic food" regarding margarine. But after avoiding for 9 months I'm still somewhat sensitive to milk products so figure I should use marg instead of butter. (If I'm going to ingest milk I'd rather do it with something like cheese.) I wish all the food companies would quit using Nutrasweet, sucralose, etc., and just use crystalline fructose since that's a natural sugar and probably better for us. It was hard for me to kick my Diet Coke habit, but I'm glad I did--now I only have one DC a month or less often.