There are many pros and cons for using a liquid diet for weight loss. This method can result in rapid weight loss, but people who use it often lose muscle instead of fat. Still, many medical professionals recommend this type of diet for the most seriously obese patients who need to lose large amounts of weight in a quick time frame. Some patients who have lost weight on a liquid diet say that they put a majority of the weight back on relatively quickly.
A liquid diet works by depriving the body of nutrients and calories from solid food. When it doesn't get enough calories, the body begins to use its own fat stores for energy. People are able to live for far longer on liquids than on solid foods alone, so this is far safer than simply depriving the body of any nutrients by stopping all caloric intake completely. The body begins to go into a starvation mode, however, which causes it to store all available nutrients until a steady diet resumes.
The benefit of using a liquid diet for weight loss is that the weight of the liquid in the stomach fools the body into thinking it is full, helping to turn off the hunger mechanism. The mind does not focus on being hungry and the dieter is not feeling the urge to eat all of the time, effectively allowing the weight to come off. Once the liquid diet has been abandoned, however, the body attempts to rapidly replace all of the weight lost.
The weight loss achieved by this method is typically not sustainable over the course of a lifetime. The benefits are usually temporary, while many of the harmful effects of the diet are life-lasting. A successful diet should include lifestyle-changing activities, like regular exercise and eating controlled portions of healthy foods, and the liquid diet is only a short-term solution that commonly brings long-term problems with it.