Congratulations for losing 100 lbs! You're exactly right. I weigh myself every day too, and it's all about DEPRIVATION. I don't buy ice cream, potato chips, cookies, cakes, bagels, potatoes, candy, etc. (I just fantasize about them.) LOL
I basically don't eat a lot all week, and then on Saturday I have McDonald's or something. I've kept it off for a year now. I don't ever want to be overweight again.