If your starting weight falls into the obese range on the body mass index, it is not impossible for your weight to change up to 20 pounds in a single day. But that amount of weight loss may not be very noticeable on a larger frame. However, if you are a petite woman and you lose 20 pounds that amount of weight loss can be the difference between several clothing sizes. It would be nearly impossible (and terribly unsafe), however, for a tiny woman to lose that much weight in a day. If you are smaller, you are likely to have less weight to lose and it will come off a little bit slower. When your starting body size is larger, you are likely to lose more weight at a faster rate—especially in the early days of in your program. You should include flax seed oil in smoothies or fruit juices if you are working out to lose quick fat. The omega 3-rich element is high in fiber content, and it can decrease irregularity and water retention. It also helps in growing metabolism rate.