Do Fasting Diets Work?
Myth

Fasting removes toxins from the body.

Does Fasting Remove Toxins From the Body? Do Fasting Diets Work?

Fasting diets that involve non-extreme forms of fasting (like intermittent fasting) have been shown to have potential health benefits (like weight loss for example), meanwhile fasting diets (especially extreme fasting diets) have also been shown to have some health risks. With those pros and cons in mind, and to the point of our page, there is however no clear evidence that shows fasting itself removes toxin from the body.[1][2][3]

In other words, fasting diets may have health benefits, and they may have some health risks, but fasting diets that claim to have a detoxifying effect lack scientific backing.

The Science Behind Fasting Diets

Scientific research shows the body can remove toxins whether a person fasts or not. In fact, fasting has health risks as the body needs liquid, energy, vitamins, and minerals to detox.

Furthermore, even non-fasting versions of detoxifying diets done with a colon cleanse, juicing, and herbs have been shown to have health risks and lack scientific backing. Most diets with the words cleanse or fast in them are on shaky ground at best when it comes to “removing toxins.” This does not mean there is no merit in non-extreme forms of fasting however. We explain these conclusions below.[4]

The caveat: Abstaining from putting “toxins” in one’s body most certainly has a positive effect. Thus, to the degree that “fasting” means abstaining from putting toxins in one’s body, then “fasting works” in this respect to detoxify the body. What we conclude here is that the research shows the body can remove toxins whether a person fasts or not, and that basics like vitamins, minerals, calories, and liquids are vital for the natural detoxication process (although we note not everyone agrees with all aspects of our conclusions). We are not saying that fasting has no positive benefits, only that the idea that abstaining from eating and/or drinking is itself something that detoxifies the body. Comments are welcome below.

THE FASTING DEBATE: Not everyone agrees that fasting doesn’t work to remove toxins, so while our research seems to indicate that the idea that fasting science is on shaky ground when it comes to detox, it doesn’t mean that you should stop here and call it a day. One of our readers suggested checking out, Valter Longo, Luigi Fontana, Dr. Fung, and Mark Mattson. So check them out and make up your own mind. It is clear fasting has some benefits (for example fasting within 24 hour periods can stimulate fat loss), but here our conclusion is that the “fad fasting diets” (especially those that claim that fasting will “detoxify”) seem to be more “fad” than science. Prove us wrong in the citations below by sharing studies or smart articles!

What Happens To Your Body When You Fast?

TIP: A healthy adult can get away with intermittent fasting, but doesn’t need to fast for health reasons. Religious or spiritual fasts are part of many peoples’ practices. An unhealthy adult is at greater risk for fasting, but may benefit from a strict diet that promotes the natural removal of toxins. In both cases, experts advise seeking advice from a medical practitioner before proceeding.

Why Does Fasting Have Health Risks?

When you fast (meaning you go without food or water) you run the risk of depriving the parts of your body that work as natural detoxification centers of resources they need to remove toxins including your liver, lungs, colon, kidneys, lymph glands, skin, etc. Depriving your body of resources that it needs can cause stress, which can in turn cause cell oxidation, which is one of the most “toxic” things that can happen to a body (especially a body lacking the antioxidants found in healthy foods).[5]

Does Fasting Have Health Benefits?

A cleansing fast that includes a healthy diet rather than total deprivation can be healthy. Limited fasting may expedite the shedding of fat-based toxins via weight loss. Fasting can also limit the number of new food-based toxins entering your system. Fasting can have mental health benefits, and of course, fasting can have spiritual benefits; it is often a religious practice.[6]

FACT: A limited number of studies have shown health benefits related to fasting, but this data should be weighed against the larger pool of data warning of health risks. See: How Intermittent Fasting Might Help You Live a Longer and Healthier Life.

How Long Can a Healthy Adult Safely Fast?

The average healthy adult can fast for about two days safely, but for those trying to cleanse their bodies for health purposes a healthy diet is safer than the far riskier diet involving total fasting. The human body can go many days without food or water, but more than a few days is unhealthy.[7]

What if you stopped eating?

What is a “Toxin”?

The word toxin broadly refers to any environmental toxin, biotoxin (toxin of biological origin), or food-based toxic substance that can be dangerous to human health. When discussing fasting, toxins are harmful minerals, toxic medications, excess hormones, waste products, toxic metabolites, foreign invaders like bacteria, fungi, viruses, and cancerous cells, oxidants, etc. stored in the body. Used very loosely the term toxin can include anything from table sugar to food additives, but this wouldn’t provide a scientific definition.

This Is NOT NATURAL

What is a Cleansing Fast?

The theory behind prolonged fasts is that there are two kinds of toxins; water-based toxins that are flushed out by the liver and kidneys; and toxins that the fat cells absorb. Water based toxins are flushed out with cleansing teas or water. Causing the body to shed fat cells involves fasting for long enough for the body to have burned all its carbohydrates, begin metabolizing fat, and entering ketosis.

Our livers typically eliminate toxins quite efficiently; the lymphatic system protects the body further; bile will dissolve fats and eliminate them along with dietary fiber in bowel movements. The kidneys will help filter water soluble waste and dispose of it in urine. Our cells can renew themselves subject to the Hayflick limit and our overall health.[8]

The argument made for cleansing fasts is that our bodies tend to be defective and need outside help to function properly. There is absolutely no scientific basis for this assertion given a healthy individual. If you are a person with a poor diet, health issues that impact digestion and G.I. tract issues or other problems that have led you to consider fasts or cleanses, it is advised that you see a medical practitioner before proceeding with fasting or extremely limited diets. To hear some sensible advice about simple, inexpensive ways to become healthier you may want to listen to Dean Ornish’s TED Talk[9].

Dean Ornish: Healing through diet

Are Enemas and Cleanses Beneficial?

Our intestinal tracts generate about 70% of our antibodies. The antibodies attach themselves to bacteria, viruses, and toxins and prevent them from being absorbed.[10] Our gut flora helps us prevent disease, maintain electrolyte balance, and eliminate body waste regularly. The large intestine contains 30 genres of organisms of over 500 species that contribute to the production of vitamin K and short-chain fatty acids, which facilitate the breakdown of dietary carcinogens.[11] Scientists are only just beginning to discover the many organisms in the human colon and their function. The mammalian colon contains one of the densest microbial communities on earth.[12]

Interfering with a naturally healthy colon can cause damage to your body. Enemas, also knows as cleanses, generally use water, which you can mix with herbs, enzymes, teas, probiotics, etc. Even if the substances used for the enema are perfectly safe to drink, they may not be safe as colonics. Organic substances can contain pesticides and fillers; chlorinated tap water may damage mucus in the intestinal lining and kill useful gut flora; chemicals in the liquid may contain substances like caffeine that can be absorbed by the intestinal lining and cause dangerous toxic reactions. Also, frequent use may damage the body’s ability to defecate normally without them.[13]

How Can Fasting be Made Safer?

You can fast more safely if you take care to ensure good nutrition whenever you are not fasting. Proper hydration is of extreme importance. Heartburn, stress, and headaches can present problems for those fasting. Your body can go much longer deprived of food than when deprived of water.

Does Fasting Help You Lose Weight?

Fasting is not a proven strategy for weight loss. It only helps you lose weight in the short term. In the long-term, it typically causes weight gain and adversely affects metabolism. Your body is always trying to find a good balance between energy coming in and energy going out; if you starve your body, it will respond by slowing down metabolism.

Even intermittent fasting is primarily fluid loss; any weight that is lost quickly tends to be found again quickly. For proper weight loss advice see our section on weight loss.[14]

Is It Healthy To Skip Meals?

Quick weight loss advice: A healthy weight loss plan that includes a “cleanse” would be small frequent meals high in complex carbs from plants and grains, limited calories, healthy fats, plant-based and lean proteins, and high in vitamins and minerals and lots of water. You’ll shed weight, detox, and importantly keep your body healthy. Stay away from processed foods, empty calories, and big meals. Small meals, water, fiber, and protein keep your metabolism going and water, energy, vitamins, and minerals keep your organs detoxing.

Fasting for Spiritual Reasons

Almost every society incorporates fasts for spiritual purification, which are usually brief and exclude those most at risk from adverse physical effects, such as pregnant women, those with compromised liver or kidney function, and diabetics. Most healthy people who are otherwise taking in a nutritionally sound diet can easily manage a day or two of fasting, and a large number of people across the globe fast every day during Ramadan while eating and re-hydrating at night.

FACT: Many who fast for religious reasons don’t lose weight. Consider Ramadan. Big meals are eaten early and late, which tends to cause fat storage. The lack of food or water during the day may slow metabolism.[15]



Conclusion

It can be hard to get a clear answer on fasting and cleansing diets due to all those pushing for-profit diet advice, but the science is clear. Fasting, and even cleansing diets have little in the way of proven health benefits and many have health risks. For our purposes fasting won’t do much for removing toxins, in fact fasting and fasting-like diets actually deprive your body of the resources it needs to naturally detox. With that in mind, there is still a little science backing up intermittent fasting and lots backing up healthy diets, so there is some middle ground.


Citations

  1. Intermittent fasting: the science of going without
  2. Intermittent fasting: Fad or science-based diet?
  3. Fasting-mimicking diet may reverse diabetes Periodic cycles of fasting reprogram pancreatic cells and restore insulin production
  4. Detox Diets & Cleansing: Facts & Fallacies
  5. Is fasting healthy
  6. Chronic Intermittent Fasting Improves Cognitive Functions and Brain Structures in Mice
  7. How long can a person survive without food?
  8. Hayflick limit
  9. Healing through diet
  10. Can fasting help purge the body of toxins?
  11. Bacteria in the Intestine, Helpful Residents or Enemies from Within?
  12. Human Gut Loaded with more Bacteria Than Thought
  13. The Science Behind Enemas
  14. Fasting:health benefits and risks
  15. Healthy Living Lose Weight this Ramadan


"Fasting Removes Toxins from the Body" is tagged with: Calories, Weight Loss


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Roger on

This article is so out of date it’s not funny. Google Valter Longo, Luigi Fontana, and Mark Mattson for more info on the scientifically proven benefits of fasting.

Thomas DeMichele
Thomas DeMichele on

Interesting, there are some subjects where there are two very different points of view head-butting, perhaps this is one of them.

We’ll do another round of research. Thanks for the notes.

Laura on
Supports this as a Fact.

Fasting not only cured my GERD but it also cured my cravings for junk food and sugar and it made me much less inclined to overeat. I’m glad I decided to NOT listen to the “experts” on this.

Incidentally, I’m no conspiracy theorist, but I wonder if these “experts” who warn against fasting are paid by the food industry. It wouldn’t surprise me.

Thomas DeMichele
Thomas DeMichele on

So I don’t in any way dismiss this. Consider, if a person puts toxins in their body all the time, then abstaining from those toxins will have a positive effect on health. In that respect, “fasting works.”

What we conclude here is, based on our research (which could have included peer-reviewed works that are ultimately shown to be wrong or biased in some cases), is that if one has a healthy diet then the body will detox without fasting… and further that there is a lack of studies showing fasting diets work better than healthy eating, and studies have instead shown health risks related to fasting.

Certainly we could be skeptical, and question if the food industry has a hand in the research, but I’d be hesitant to try any extreme fasting diets or long term fasting diets without clearer research.

Does that make sense? That said, thanks for your feedback, always good to hear first hand accounts.

Laura on
Supports this as a Fact.

Who even wrote this?? The citations don’t even look credible. There has been so much research into fasting for health and weight loss and there are so many benefits. Google Dr. Jason Fung for one example. He treats a lot of obesity using fasts and explains how it all has to do with insulin.

Thomas DeMichele
Thomas DeMichele on

While my initial reaction to fasting was “oh, it would make sense if it helped to remove toxins!” All of our research turned up studies to point to this not being the case.

Now, does that mean that intermittent fasting can’t help one lose weight, or that insulin isn’t tied to weight loss and hunger? No, not at all. What it means is that studies point to the idea that “fasting itself removes toxins” as not being correct. That is what the article is saying.

Consider this excerpt:
In another study, Mattson and colleagues explored the effects of intermittent and continuous energy restriction on weight loss and various biomarkers (for conditions including breast cancer, diabetes and cardiovascular disease) among young overweight woman (Int J Obesity 2011;35:714–27). They found that intermittent restriction was as effective as continuous restriction for improving weight loss, insulin sensitivity and other health biomarkers.

Mattson has also researched the protective benefits of fasting to neurons. If you don’t eat for 10–16 hours, your body will go to its fat stores for energy, and fatty acids called ketones will be released into the bloodstream. This has been shown to protect memory and learning functionality, says Mattson, as well as slow disease processes in the brain.

But perhaps it isn’t so much the fasting that produces health benefits, per se, as the resulting overall reduction in calorie intake (if, that is, you don’t overeat on nonfasting days, which could create a caloric surplus instead of a deficit). That appears, at least, to be the case in slowing diseases such as cancer in mice, according to Dr. Stephen Freedland, associate professor of urology and pathology at the Duke University Medical Center in Durham, North Carolina.

//www.ncbi.nlm.nih.gov/pmc/articles/PMC3680567/

Or check out this: //scopeblog.stanford.edu/2016/07/07/intermittent-fasting-fad-or-science-based-diet/
Or this: //www.sciencedaily.com/releases/2017/02/170223124259.htm

As we can see, there are potential weight loss and health benefits to some forms of non-extreme fasting (like intermittent), but there is no conclusive evidence that fasting detoxifies the body itself.

Happy to keep researching and hearing counterpoints. I’ll look more into Dr. Fung, but generally I’m looking for studies and not claims of single individuals who have earned the title Doctor.

Braden on

Lmao. Thomas. You talk too damn much. Fact. Fasting helps clean and rid cells in the body of waste. Fact. IF you don’t eat you will lose weight. I don’t care who you are. WHat you do for a living. Or what you’re diet is. If you don’t consume food. You will lose weight. It can be as simple as calorie in calorie out. To as complex as why insulin levels affect fasting. Dude. Fasting works. On a personal level. Fasting has worked for me. There are plenty of studies to support my “claims” that are also fact. And there are plenty of personal testimonies for the world to hear. Fasting works.

Michelle on
Supports this as a Fact.

“Research by Skidmore College exercise scientist Paul Arciero has found that a balanced, protein-pacing, low-calorie diet that includes intermittent fasting not only achieves long-term weight loss, but also helps release toxins in the form of PCBs from the body fat stores, in addition to enhancing heart health and reducing oxidative stress.” I would be interested in your views on whether this study has any credibility in the findings?

Thomas DeMichele
Thomas DeMichele on

I would have to research this more and think it over. Think you are referring to this article and the related research (which I haven’t yet found): //www.sciencedaily.com/releases/2017/01/170111184102.htm

Thanks for the share though.

AHD on

This article is full of misinformation!

Thomas DeMichele
Thomas DeMichele on

Not purposeful misinformation, but I am open to any debate or counterpoints. That said, I need something to go off of. Many points were made, please feel free to take issue with any specific one 🙂