Liquid diets usually involve replacing meals with liquid that might include shakes, fruit drinks or soups in order to experience rapid weight loss. Liquid diets are often used after gastric surgery due to the inability of the stomach to absorb the nutrients from solid foods. They are usually used for short-term weight loss, and can result in rapid weight loss that may or may not be sustainable over the long term.
Slim-Fast
The Slim-Fast diet has been around for about 25 years and uses shakes to encourage weight loss among dieters. It purports to help dieters lose up to 2 pounds per week using its product line, which includes shakes, meals, snacks and meal bars. Slim-Fast recommends replacing two meals and one snack with shakes, and eating a dinner that is low in fat, to reduce and control calorie consumption. The products can be purchased at grocery stores for $12 to $15 for a 12-pack of pre-mixed diet drinks. It is also available in powder form that should be mixed with milk for best results.
Optifast
Optifast says that its shakes help dieters maintain nutritional levels while dropping excess pounds by consuming its drinks and shakes as a meal replacement. The drinks use calorie and portion control to encourage weight loss. The Optifast company offers support and counseling at clinics and on its website to clients as well. It offers pre-mixed and powder drinks, shakes, soups and nutrition bars. The company recommends replacing up to two meals per day using its products in order to lose weight. Optifast can also be used after bariatric surgery as a meal replacement. According to tristarmedical.com, the website of a medical clinic in Los Angeles, drinking five servings of the Optifast drink provides 100 percent of recommended daily nutrients. Optifast can be purchased at clinical centers or from medical providers. The Optifast program can run anywhere from $8 to $12 per day, or up to $400 per month.
Medifast
Medifast liquid diets consist of shakes that contain protein, vitamins and minerals in order to meet overall nutritional needs. The products are low in lactose and soy-based, and purport that they are heart-healthy. There are different packages for different weight-loss goals, and products can be purchased online through the Medifast website, doctors' offices and other online sources. The Medifast liquid diet includes soups, shakes and fruit drinks to help you to lose weight fast. The diet induces weight loss through calorie restriction. The Medifast website also has food that can be purchased, including vegetarian fare. Medifast claims that program participants can lose up to 5 pounds per week on its programs. The program has different requirements for men and women, with men's shakes generally having a higher protein content. The Medifast program costs about $11 per day or $300 per month.
Advantages
Liquid diets have some advantages when you are trying to lose weight rapidly. In order to lose 1 pound of fat, you have to eliminate or burn 3,500 calories. Liquid diets work by restricting calorie intake and will generally cause you to lose weight faster than a normal, nutritionally balanced diet. For instance, on the Slim-Fast diet plan, you might average 1,200 calories per day, which is 800 to 1,800 less than the recommended daily calorie intake for moderately active to active women and men according to the Food and Drug Administration. A diet this restrictive might help you to lose up to 5 pounds per week.
Disadvantages
Losing weight too quickly might result in the loss of muscle as well as fat. Calorie-restrictive and liquid diets might also result in nutritional imbalances and illness. According to dietspotlight.com, a website that reviews different diets, liquid diets can also cause dizziness, anemia, constipation, cramps, and in more severe cases, cardiac arrhythmia. Hanging, loose skin is also a side effect of losing weight too quickly. In addition, calorie restriction is hard to maintain and weight might be regained quickly when regular eating resumes.