Do you need a detox? Probably not.

I often hear people say they need to do a “detox” or “cleanse” before starting their diet. Typically my response is “Okay, why do you need to do that?” Nine times out of ten the response is “I have been eating a lot of junk food and feel like I need to reset my gut before starting to eat healthy again.”

Today, I want to dive into why a detox may not be the best idea but also look at any beneficial effects to this approach. As a nutrition coach and exercise scientist, I want to weigh both the pros and the cons and try to provide an unbiased point of view.

For the ease of this article, I will use the terms “detox” and “cleanse” interchangeably. So, without further ado let’s dive in.

How exactly does a detox work?

Generally speaking, the idea of a detox is to remove toxins from your body by drinking fruit and vegetable juices to provide the body with an abundance of micronutrients, vitamins and minerals. Drinking these juices gives the body the nutrients it needs in order to function at its best, to heal the gut and to clean out the digestive tract- at least that is the idea. People might want to do a detox because they eat too many foods that are not rich in vitamins and minerals such as fast food or other highly processed foods. Another reason a detox may be used is to kickstart “healthy habits” by drinking these juice blends. A detox can last anywhere from a few days to a whole month which generally aids in weight loss as well.

What actually happens during a detox?

When fruits and vegetables are juiced they lose a significant amount of their nutrients, particularly fiber. Fiber is proven to help relieve constipation, slow down gastric emptying, lower blood sugar, keep you fuller longer and feed the healthy bacteria in your gut. If a person does not eat the whole fruit or vegetable they will likely experience diarrhea, which can lead to a lack of nutrient absorption and dehydration.

One beneficial outcome of detoxing is weight loss. As noted earlier, this is usually due to diarrhea and eating significantly less calories because all the calories consumed during a detox diet are from juices. Intense hunger is also a side of effect of prolonged detoxes because juices, smoothies and other liquid based calories digest faster, since there is less work for the intestines to do during the digestive process.

Do detoxes actually get rid of toxins in the body?

There is not much research on this topic. The research that is available shows very little benefit, if any, to performing a detox diet.

Juiced fruits and vegetables are not the only ingredients in detox drinks. There are often specific ingredients added to them which have cleansing or detoxifying properties such as coriander and nori. These “detoxifying” ingredients help to “clean the gut” and remove heavy metals from the body. While it has been proven that coriander is effective at removing certain metals from the body such as lead, cadmium and mercury, you do not have to get coriander from a juice cleanse.

An important factor to note about removing heavy metals from the body is that our bodies already do this through the liver or kidneys. The liver processes and filters out any harmful substances or heavy metals and turns them into bile by-products or they go into our bloodstream as blood by-products. Once the harmful substance is in bile form, it is then moved through the intestines and excreted as feces. Harmful substances or metals that go through the blood by-products are filtered by the kidneys and removed as urine. Therefore, performing a detox diet is not necessary for “detoxifying” the body.

Other cons to detox diets

Earlier I mentioned that detox diets provide a decent amount of vitamins and minerals, which is great, but what about other macronutrients like fat and protein? One detox diet only yielded nineteen grams of protein per day. Granted the plan is only three days long, it is still a very insufficient amount of protein. In addition to the lack of protein, there is a significant amount of calorie restriction. While calorie restriction may be beneficial for weight loss, it can lead to binge-eating due to the sudden decrease in caloric intake. This could then lead to very disordered eating and or a “yo-yo diet” effect.

All of this to say, following a detox diet is not necessary and not very helpful. But as promised, let us look at the potential benefits of performing a detox diet.

Benefits of a detox diet

There are none.

Just kidding, there are a few:

1. Rapid weight loss

2. High amount of micronutrients

3. Increased water intake

4. Increased fruit and vegetable intake

Hopefully by now you realize that the four listed “pros” are not really pros. If you forgot why, here is the spark-notes version: 1. Rapid weight loss is not really a pro because it often leads to binge-eating.

2. High amounts of micronutrients is not really a pro because you miss out on other important nutrients such as protein and fiber.

3. Increased water intake is not really a pro because detox diets often lead to diarrhea which causes dehydration

4. Increased fruit and vegetable intake is not really a pro because you are not eating the entire fruit or vegetable — just the juices.

Conclusion

Don’t waste your time, money and energy on detox diets. Unless your doctor told you that your liver is functioning below normal, it can detoxify your body just fine. Even if your liver is not working as it should, it is not likely that you would be prescribed a detox diet to fix it.

If you are trying to lose weight and adopt healthy habits, consider working with a trained professional who can help you achieve your unique goals. Another good option is to start by eating less highly processed foods and more nutrient dense, minimally processed whole foods.