I don't think I saw this link anywhere else in the thread, but apologies ahead of time if its already been posted. I saw this quiz awhile ago and found it to be quite interesting. http://hp2010.nhlbihin.net/portion/keep.htm

On a separate, but related note - it seems (from the media at least) that surgery - gastric bypass- is getting be more popular for drastic weight loss. When you think about it what the surgery is pretty much about, is enforced portion control. They make the person's stomach so small that they can't eat too much at once. Yup Kitsune, if you regularly over eat you can stretch out your stomach so that you need more food to feel full, but if you have the will power to eat less you can shrink it back down to a point as well - I do not know how far you can take this before its too stretched to go back -I would bet its like skin and can only take so much stretching before it won't go back.