People use liquid protein diets to treat morbid obesity. The two types of liquid protein diets include at-home versions like Medifast and medically supervised programs like the University of Texas Southwestern Medical Center Liquid Protein Diet Program. People consume less than 1,000 calories on these diets to jump-start rapid weight loss. The program at the Southwestern Medical Center includes protein powders that dissolve in water, milk, tea or yogurt. Although rapid weight loss does occur on these diets, there are some drawbacks you should be aware of before embarking on such a program.
Vanderbilt University Psychology Department provides information about some of the disadvantages of a liquid protein diet. These diets promote rapid weight loss; however, this weight is primarily water and lean muscle tissue, and dieters’ metabolisms slow down because of the reduced amount of calories they are consuming. Thus, when they resume regular eating habits, dieters often regain this weight plus extra pounds.
Another disadvantage of liquid protein diets is an electrolyte imbalance because of the lack of complete nutrients in the diets. Electrolyte imbalances cause irregular heartbeats, muscle cramps and dizziness.
Another disadvantage of liquid protein diets for women is amenorrhea, or menstrual cessation. The U.S. National Library of Medicine says menstrual cessation occurs because of rapid weight loss. The menstrual cycle may gradually or suddenly stop.
Before beginning a liquid protein diet, always talk to a medical professional, as people on liquid protein diets are more likely to develop gallstones. This occurs because rapid weight loss causes an excess of bile to form, which overwhelms the gallbladder, causing painful stones to form. If stomach pain causes you to believe you have gallstones, talk to your doctor about medications that can dissolve stones and reduce pain.
Digestive problems like constipation are another of the disadvantages of liquid protein diets. The National Digestive Disease Information Clearinghouse says that constipation occurs because liquid protein diets do not contain enough fiber to promote digestion.