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What’s the Deal With Detox Diets?

As a registered dietitian who sees a wide range of clients—from Olympic-caliber athletes to gastric-bypass candidates—
I occasionally field questions about the
efficacy and safety of detoxification (detox) diets. Never having been a fan of any diet or pattern of eating that promises excessively accelerated weight loss, I usually answer these questions with great concern because of the potential dangers of extreme fasting.

However, after a recent appointment with a client who had real success with a short-term detox program, I began to wonder: If millions of people around the globe have been following these types of diets for centuries, can they really be all that bad?

History & Promises
of Detox Diets

The concept of cleansing the body of built-up toxins is not new. In fact, detoxifying or purifying practices have been around for centuries, and the popularity of these practices is cyclical, coming back into favor every so often. Historically, many detoxification diets were based on religious beliefs and typically involved fasting. As far back as 400 bc, practitioners of ancient Ayurvedic medicine frequently recommended diets that cleansed the body of impurities by eliminating various food groups and emphasizing a plant-based diet.

Today, a diet is classified as “detox” if it involves making a change to one’s eating patterns with the goal of ridding the body of accumulated toxins. Many types of detox diets are currently practiced, and the purported benefits of such cleanses include increased energy, clearer skin, improved digestive health, better mental focus, weight loss, prevention of chronic disease and overall better health.

Some people follow detoxification diets simply as a way to lose weight quickly, whereas others consider detox part of a lifestyle change and cleansing regimen that encompasses the mind, body and spirit. American Dietetic Association (ADA) spokesperson Lona Sandon, MEd, RD, has her own theory about these cleansing regimens: “By eating certain food or drinks, or perhaps eliminating [some items] from your diet, you will decrease the ‘toxins’ stored in your body that cause inflammation and disease,” she said (Schaeffer 2008).

But how do all these toxins enter the body, and doesn’t the body have its own defenses that naturally purify our systems?

Detox Diets: The Premise

The premise behind detox diets is that by eliminating certain food groups, you rid the body of the toxins commonly found within those foods, while also giving your digestive system a break from hard-to-digest-and-absorb foods, such as meat, cheese and processed items. Detox proponents claim that by avoiding these foods, the body uses less energy for
digestion and for warding off toxins and therefore has more energy to direct
toward energy and healing.

This premise is illogical and flawed, however, because digestion typically uses only about 10% of daily calories (Mahan & Escott-Stump 2004). So going on a detox diet to conserve energy would be tantamount to quitting your job and losing your annual income in order to save the gas money it takes to commute to work. With regard to outcomes, although not all detox diets focus solely on weight loss, following any restrictive pattern of eating will usually lead to accelerated weight loss. And as for the need to purify toxins from foods, the human body is designed to do this naturally: it relies on the function of the liver, kidneys, lungs, skin and immune system for its own built-in detox system.

Types of Detox Diets

Detoxification diets vary, but they usually involve fasting, avoidance of many food groups and/or consumption of cleansing beverages. Regimens often mimic vegan diets and call for the complete removal of animal products (meats, dairy, poultry, fish and eggs) and stimulants such as caffeine. Detox diets also vary in duration but typically last from 3 days to about a month.

Most detox diets begin with a cleansing phase. This initial phase of the diet—often the strictest part—is usually a complete fast that permits only water, perhaps with a few spices or flavorings; basically, a starvation diet. Eventually, the dieter is allowed to slowly incorporate other prescribed food groups, but processed foods, stimulants and almost all animal products must still be avoided.

The two most common types of detox diets are liquid plans and those that start with liquids and then progress to solid foods.

Liquid Detox Diets

Many detoxification diets allow only liquids, and not all liquid diets are bad. Health professionals have often recommended that clients seeking to lose weight replace one calorically dense meal with a nutrient-dense, low-calorie nutritional shake. In fact, replacing one otherwise unhealthy meal with a nutrient-dense shake can be healthy and sensible. However, a long-term, liquid-only diet alone can be devoid of essential nutrients and dietary fiber, which can lead to malnutrition and gastrointestinal complications.

Often, liquid-based detox diets allow for only water-based beverages that contain a concoction of spices, such as cayenne and lemon; fruit and vegetable purées; or laxative teas. Liquid-based detox diets are sometimes viewed as glamorous because many of Hollywood’s biggest stars have followed these diets and been heralded in the press for their weight loss success (Hellmich 2009). But for those of us who are not equipped with our own entourage of chefs, personal trainers and physicians, liquid-only diets can be dangerous and frustrating and should be cautioned against. In addition, crash detox diets often focus solely on quick and short-term weight loss, missing the bigger picture. If dieters are not encouraged to make major lifestyle changes or not taught basic healthy eating skills, they are bound to revert eventually to their old habits of eating poorly once the fast is over, and the lost weight is certain to return with a vengeance. According to one study, researchers determined that even though dieters can lose 5%–10% of their weight in the initial phases of a detox diet, up to two-thirds of people regain that weight (and then some) within 4–5 years of ending the diet (Moores 2007).

Liquid-Solid Detox Diets

In addition to liquids, some detox diets allow for plant-based solids, which provide essential vitamins, minerals and macronutrients, such as carbohydrate, protein and fat. These combination diets are often touted more as a lifestyle change as opposed to a quick weight loss plan. Clients who follow intensive but nutritionally balanced detox diets and change their behavior may benefit from an abrupt deviation from their old eating habits.

Liquid-solid detox diets typically last for at least 10 days and continue for various durations, sometimes months. These combination diets usually include nutrition education, meditation and yoga
as part of an overall lifestyle change. Although most healthcare professionals recommend making moderate changes over a long period of time, many clients find it easier and more effective to change their bad habits by quitting “cold turkey.”

Drawbacks to Detox Diets

Many nutrition experts, including the ADA, would likely label today’s detox diets as food fads or fad diets. A fad diet typically makes an unreasonable or exaggerated claim that by eating or avoiding specific foods, nutrients or supplements, a person can experience special health benefits, such as a cure for a chronic disease or quick weight loss. At the very least, experts would probably consider the premise of detoxification diets a case of misdirected claims.

According to an ADA position statement, a claim is misdirected when it leads consumers to make incorrect inferences or broad generalizations about the health benefits of a food (read: diet) (ADA 2006). Put simply, a misdirected claim may lead the public to believe that a particular food or diet is more beneficial than it really is. While the Federal Trade Commission, the U.S. Food and Drug Administration and other governing agencies oversee many products and claims on the market, it is often difficult for federal regulations to keep pace with the boom in diet practices and related supplements. Indeed, in a market in which hundreds of billions of dollars are spent annually on millions of functional foods, dietary supplements, natural/organic foods and personal care products, it is impossible for any agency to keep up with every new item that claims to solve weight loss conundrums or resolve health problems. In a nation in which most consumers get their nutrition information from TV, magazines and the Internet (ADA 2008), it is no wonder that misinformation and misinterpretation run rampant.

Detox diets carry both long- and short-term health consequences. The short-term negative effect of a detox diet would be any physical harm caused by drug-nutrient interactions or the potentially toxic components in the cleansing products. A serious long-term consequence would be delayed treatment of a pre-existing health condition if the dieter was fasting to self-treat a chronic disease. Over time, dieters may also develop psychological issues, such as diminished self-efficacy. This is certainly evident when a client who wants to lose weight “fails” to complete a detox diet and then gives up entirely, thinking, “No other dietary change will ever work, so why bother at all?”

Side Effects of Detox Diets

The reported side effects of detox diets are positive or negative, depending on whom you ask. The positive results are often touted by Hollywood starlets who boast of quick weight loss, brighter complexions and greater energy levels. Devotees of detox diets typically claim to feel “lighter,” have better mental focus and in general have a sense of improved well-being. Proponents also cite the lifestyle changes as a major benefit and feel that they are reducing their carbon footprint as a result of following a “green” or vegan diet.

The negative side effects of prolonged calorie restriction are less often reported by the media but range from irritability and fatigue to headaches and other aches and pains (Moores 2007). Even though fasting for brief periods of time is not likely to cause harm to otherwise healthy individuals, most healthcare professionals agree that long-term fasts can alter metabolism and also gut integrity. Should gut integrity be weakened for a long period of time, bloating, diarrhea, constipation and cramping will commonly occur when food is finally reintroduced. Additionally, lengthy fasts can lead to vitamin and mineral deficiencies, muscle wasting, skin breakdown and dangerously low blood sugar levels. Detox diets that call for long-term laxative use are not only inconvenient; they can also cause serious constipation and other gastrointestinal distress once laxative use is discontinued.

Detox diets that lack essential nutrients and antioxidants can also impair immune function, leading to many complaints of sore throat and other illnesses. According to Richard DeAndrea, MD, ND, founder of the “21 Day Detox Diet,” detox dieters may become ill because once their metabolism works more effectively, toxins that are usually buried under layers of fat tissue are released into circulation as the fat breaks down. (Not surprisingly, DeAndrea sells a supplement that will assist the body in further breaking down these toxins!) However, other medical professionals say that any resultant illnesses are more likely related to the drop in immune function caused by the fasting and imbalanced nutrient intake of detox diets.


In summary, detox diets should be attempted only by individuals who are in overall good health and who have first discussed the consequences of extreme dietary restrictions with their healthcare provider. Populations who must steer clear of detox diets include individuals with a compromised immune system, growing children and adolescents, pregnant and nursing women, elderly individuals and the morbidly obese who have secondary conditions, such as hypertension, diabetes and cardiovascular disease.

There is little to no clinical research to suggest that anyone would benefit from detox diets or even to indicate that such diets really work. After all, the human body is an amazing organism; it comes equipped with natural cleansers and does an excellent job of clearing out toxins as needed. While certain chronic diseases can interfere with the body’s cleansing processes, in most healthy individuals the body efficiently clears out toxins without resorting to a detox diet.

Some detox diets are probably safe if followed for only a day or two and may provide a boost for people who are in a downward spiral of dieting. But for my own clients, I will continue to recommend making smart lifestyle choices and taking small steps toward better health. My advice will be to eat from all of the recommended food groups and exercise on a daily basis. It sure beats drinking a dubious, laxative-based liquid and having to rush to the restroom every 5 minutes!

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