The Master Cleanse or Lemon Detox Diet, Fat Flush, 21 Pounds in 21 Days, the Liver Detox Diet ... these are just a few of the so-called "detoxification" diet plans that have become all the rage. Holistic healers and diet gurus are pushing all sorts of products and regimens that are supposed to help purge our bodies of chemicals and toxins, while helping us to lose weight -- fast!

But do you really need to rid your body of dietary "poisons"? Do your colon, liver, and lymph nodes need to be flushed and cleaned? And should you try one of these detox diet plans for weight loss and optimal body performance?

According to doctors and registered dietitians who spoke to WebMD, the answer is a resounding "no." A day on a detox diet program probably won't hurt you, but there's little point in following these restrictive diets - and they can do far more harm than good, says Michelle May, MD, author of Am I Hungry? What to Do When Diets Don't Work.

"Extreme diets generally do little more than cause frustration, are potentially dangerous, and are in general are a waste of time and money," May says.

What is a 'Detox' Diet?

Most detox diets promote herbs, pills, potions, colonics, and/or fasts to rid the body of impurities. They also promise quick weight loss. And yes, you will shed unwanted pounds -- not because of any medical magic, but because these plans are super-low in calories.

"You will lose weight, but it is the not the unhealthy fat you want to lose but precious body protein and fluids," says May.

Detox diets tend to be extremely restrictive, allowing only unprocessed plant foods, which are supposed to assist the lymph, kidneys, and liver with the detox process.

Gallons of water or specially formulated drinks along with herbs (usually only available on the diet's web site) are generally the only liquids allowed. One regimen calls for liquids (various concoctions including laxative teas) for 10 days, without any solids. Coffee, tea, alcohol, processed foods, and animal products are not commonly part of any detox diet plans.

Enjoying a plant-based diet is perfectly healthy, but most detox diets go to extremes, experts say.

"The limited variety of foods and beverages and minimum calories is of concern because it is very difficult to get all the nutrients and energy you need for good health with such restrictive regimens," says Christine Gerbstadt, MD, RD.

Unless you have religious or cultural reasons to fast or follow detox programs, she advises against them.

Potential Dangers of Detox Diets

Not only do the experts who spoke to WebMD say that we don't need detox diets, they believe these regimens have the potential to be harmful.

"Massive fluid losses upset the delicate fluid and electrolyte balance, can cause gastrointestinal distress, headaches , fatigue [and] irritability, and can lead to dehydration ," says Gerbstadt.

Colons don't need flushing unless you are prepping for a medical procedure like a colonoscopy. Colonic enemas tamper with the body's natural fluid and electrolyte balance and can lead to infection, irregularity, and dehydration. Instead, Gerbstadt suggests a high fiber diet.

"Eating more fiber in whole grains, bran, fruits, vegetables, beans, and nuts is a safe and natural way to add bulk to your diet," she says.

Gerbstadt also warns that fasting or following very restrictive detox diets can slow your metabolism , making it harder to lose weight once you start eating again.

"In many cases, they result in rebound overeating because of excess hunger, deprivation, and an out-of-control feeling that is not because of a metabolic imbalance or addiction but instead driven by the deprivation of the diet plan," says May.

What's the Appeal of Detox Diets?

Is there any evidence that detox diets do what they promise? Experts note that most of the studies presented to support detox diet regimens have not been published in peer-review journals, the gold standard for scientific evidence.

Yet people continue to try detox diets and other regimens promising quick weight loss. Disappointment with past dieting experiences and the search for a "magic bullet" is what usually drives people to quick-fix diets, experts say.

Instead of embarking on an unrealistic diet plan, May suggests looking inward to identify the issues that are driving unhealthy behaviors. "What is causing you to overeat? Is it a lack of awareness, making poor decisions, mindlessly eating, reaching for food to meet other needs?" she asks.

Then, she suggests, evaluate your eating habits and make small, gradual changes that you can sustain. Concentrate on eating healthy foods rather than forbidding entire categories of foods.

"Drastic, restrictive [diets] or forbidden foods have a very powerful effect, triggering cravings and giving food power over you," explains May.

Your best bet, experts say, may be to consult a registered dietitian for a customized diet plan that will help you accomplish your personal goals in a safe and effective manner.

The Natural Way to Detox

The best way to "detox" the body is simply to let your body do its job. Unless you have a medical problem, your body takes care of itself quite nicely, experts say.

"The liver and kidneys are nature's best-kept secret, because they are the weapons to eliminate toxins from your body," says Gerbstadt. "If you are concerned about certain substances in your diet, it is easier and safer to simply eliminate [those substances] rather than engage in unhealthy detox plans."

Be mindful of what you eat, drink plenty of fluids, and avoid excess medications and alcohol, say the experts.

If you want to promote water loss, Gerbstadt suggests doing it naturally by consuming cranberries, celery, asparagus, and herbal teas, and limiting salt.