Marina Kalcina 1 July 2019 Weight, Food Drop a dress size one week, gain it back the next. This is why fad diets really don’t work. Marina Kalcina 1 July 2019 Weight, Food Over the weekend a post went up on our Insiders Facebook page about dropping a dress size in a week. To be clear: we did not write this post. We did, however, delete it. Because it went against everything we stand for.