One of the popular methods is the "liquid-only" diet. They claim they can reduce your appetite through a diet that eliminates solid foods and replaces it with a low-calorie cleansing drink that helps you remove toxins from your body and lose weight in just a few days.
Superstars like Beyonce say the extreme liquid diet worked for her. She told Oprah in an interview that it helped her prepare for her role in the movie "Dream Girl," in which she played a singer. She says she only ate vegetables, but the main portion of her diet was a low-calorie drink known as a "Master Cleanse." It's made with lemon juice, maple syrup, cayenne pepper, and water. The entertainer says she lost 20 pounds on it in just two weeks.
"Why did she lose 20 pounds? Because 6 to 9 of those pounds was just pur
e water," said Dr. Melinda Southern, a nutritionist with the LSU Health Sciences Center.
Dr. Sothern says with extreme, low-calorie diets, it's easier to lose water weight than fat. However, she cautions those considering using the diet that water weight will quickly return once they stop the diet and return to eating regular solid foods. The nutritionist says that's because the human body normally retains water from solid foods. Beyonce told Oprah she regained the weight once she stopped the cleansing diet.
"It's one of the reasons nutritionists point to when they say there is no scientific evidence that shows liquid dieting is a healthy long-term weight loss solution, nor that it cleanses toxins from your body. If you talk to your physician, he will probably tell you not to do it," Sothern said.
The cleansers range in price from as low as $11 to as high as more than $100.
Some require you give up all solid foods and take the cleansing liquid along with herbal supplements. However, others are a combination of the liquid juice and low-calorie foods like veggies.
But nutritionists also warn that with extreme low-calorie diets, your body loses muscle. As a result, the loss of muscle slows your metabolism, reducing the amount of fat your body burns.
"When your muscle is wasted, your rate of burning calories is lower, and once you complete that diet, you will gain weight faster than ever," Sothern said.
Sothern said most people will most likely experience extreme side effects on diets like this, such as irritability and mood swings, fatigue, dizziness, and headaches. Most importantly, if you overuse them, you can put dangerous stress on your heart and kidneys.
"There are documented cases and studies where the kidneys shut down because there were not enough carbs to sustain normal metabolism," Sothern said.
As with any diet, the LSU nutrition expert says to check with your physician before starting a cleansing diet, especially if you have any major medical problems. She also warns against staying on them for too long.
"If you try to only have liquids and supplements for a month, you would damage your kidneys. That would be too long," said Dr. Sothern.
Provided you have a physician's approval, Sothern recommends choosing the seven-day cleansing program that does not require fasting but allows you to eat low-calorie foods with it. She says the week-long diet would have the least potential negative effects on your body while helping you achieve your goal.
Also, check with a dietician to make sure you're eating the correct low-calorie foods with the liquid. That way, you can achieve the same results as many celebrities do while preparing for a big role. But the key thing is to remember - it's not a long-term weight loss solution.