A liquid diet incorporates either partial meal replacement or all fluid consumption, which may be in the form of teas and juices. Most liquid diets may not be suitable for long-term or excessive weight loss. They are, however, of benefit for certain types of procedures—both pre- and post-op—plus they are a type of regimen that is desired following bariatric surgeries.

When liquid diets are used - Bariatric Surgery

Most physicians do not recommend a liquid diet unless an individual is to undergo certain procedures that include colonoscopy and sigmoidoscopy. In pre-operative cases, a clear liquid diet serves many functions: It can flush the bowels while decreasing strain on the digestive system. Allowed beverages include coffee, tea, sports drinks, and broth; some juices are also permitted, if strained first. Before beginning this type of liquid diet, a physician will provide a detailed fact sheet on how to proceed and for how long. Individuals who undergo bariatric surgery may be required to follow a fluid-only diet for up to ten days following the procedure.

When liquid diets are used - extreme obesity

In some cases, extreme obesity is treated with an all-liquid diet. This can be successful initially, but must be monitored by a physician for any negative side-effects. A general consensus, however, is that this type of approach will not teach individuals the necessary requirements of healthy eating to maintain the weight loss.

Liquid diets and health issues

A liquid diet may not provide the needed nutrients to maintain adequate energy levels in most individuals. Short-term weight loss can be achieved, but when liquids such as protein shakes are eventually eliminated from the diet, pounds tend to be regained. Those who embark on a juice fast—also categorized as a form of liquid dieting—may find it less than satisfactory. The lack of proteins and fiber is also at issue with many physicians. In most cases, the replacement of food with fluids, even if medically supervised, simply will not be practical in the long term for those who need to lose only a minimal amount of weight. Some individuals believe that fluids will cleanse the system of impurities, including those that have built up in the liver. These beliefs are generally refuted, with the caveat that the elimination of most processed foods is always beneficial. The concern lies mainly with a fanatical approach to a liquid diet in which one ignores the essential vitamins, proteins, fibers, and other required sources for optimum health. Ultimately, nutrition and resistance to disease will suffer in the effort to achieve a more defined physique. Incorporating a liquid meal replacement can be an acceptable way to reduce a limited amount of weight, but should be used in conjunction with regular meals. Without portion control, these diets may fail as well.

	Liquid diets are generally associated with medical procedures, not general weight loss. If you are looking to derive some of the portion control/calorie reduction benefits sometimes associated with liquid diets, perhaps you should consider the Mediterranean Diet. More on this diet below...