Can Fat Loss Cause a Toxin Release?

In this episode, you'll discover whether feeling low on energy with brain fog, lethargy, and other symptoms can be caused by "The Detox Reaction," aka toxins released when you lose fat.

Ben Greenfield
3-minute read
Episode #236

You’ve probably heard about "toxins being released from fat loss” before. Maybe you've heard a friend say something like this:detox

“Yeah, I’m on a new diet and exercise program, and I feel like crap. My trainer says I’m detoxing.”

Or even, “Ever since I started restricting calories and drinking more water I get brain fog and fatigue.”

Many will even refer to this as “The Healing Crisis," aka “The Cleansing Reaction,” “The Detox Reaction,” or “The Herxheimer Reaction.” It's described as a reaction that occurs when the body tries to eliminate toxins at a faster rate than they can be properly disposed. The more toxic your biological systems are when you start eliminating toxins, the more severe the detoxification, or “crisis,” you'll experience. You’ll often see these same type of reactions described in the realm of detoxification or cleansing programs, which often go hand in hand with fat loss programs. These reactions are typically described as signs that the treatment is working and that your body is going through the process of cleaning itself of impurities, toxins, and imbalances.

So, is there anything to this, especially when it comes to fat loss? Is there any evidence showing that people undergoing weight loss via diet and/or exercise may be releasing stored pollutants into their blood?

Can You Store Toxins In Fat?

We know that pollutants and environmental toxins can readily accumulate in adipose tissue. In one interesting study, subjects 40 years or older were separated into five different weight categories: stable weight, moderate increase, moderate decrease, large increase, or large decrease.

Researchers then took blood samples and measured the levels of toxins in the blood. They found significant correlations between weight loss and elevated levels of pollutants. Those reporting significant weight loss in the past 10 years had the highest levels of toxins in their blood, while those who’d gained significant weight in the same 10 years had the lowest pollutant levels.

Another study found that weight loss increased blood levels of five common pollutants in obese subjects, and that some of these pollutants were actually reabsorbed into the subjects’ remaining subcutaneous body fat. Even after 18 weeks of diet and exercise, toxins levels were still elevated, suggesting that the continual fat loss was steadily leaking stored pollutants. These toxins levels seems to increase, whether weight loss occurs via low calorie dieting or through bariatric surgery.

Is It Healthy For Fat Loss To Release Toxins?

So, is it a bad thing to lose weight if your fat releases toxins when you burn through it? Would obese people be better off staying obese rather than dumping a bunch of pollutants into their bloodstream? It’s unlikely. We know for a fact that lowering your body fat can lead to better quality of life and lower risks of most chronic diseases. The build-up of pollutants in adipose tissue is actually linked to adverse outcomes. For example, in a study of obese patients, those with the greatest levels of pollutant accumulation were most likely to have hypertension, glucose intolerance, and other components of the metabolic syndrome. Other research has shown a connection between toxin build-up in adipose tissue and metabolic dysfunction, indicating that even when toxins are stored away in fat, they’re still somehow causing health to be damaged.  

Could It Be Something Other Than Toxins?

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Of course, you can feel “crappy” when losing a significant amount of weight, and it can have absolutely nothing to do with toxins. For example, when you begin a diet program, you’re often restricting carbohydrates. Since carbohydrates help you to store electrolytes, the loss of electrolytes can lead to dizziness and “brain fog.” The remedy? Add more healthy sources of salt to your diet!

Most weight loss programs also include an exercise component, and this can often mean build-up of soreness, and inflammatory byproducts of exercise such as C-Reactive protein, which also leaves you feeling less than stellar. The remedy? Be sure to work in good doses of recovery in between your exercise sessions, and include strategies like an anti-inflammatory diet and deep tissue work.

And if it is toxins that are slowing you down? Take comfort in the fact that the blah feeling will eventually go away, especially if you’ve cleaned up your personal environment. Drink plenty of water, keep sweating so that your skin is able to do it’s detoxification duty, and remember that, just like any hard thing, weight loss isn’t necessarily always going to feel comfortable, so just be smart about taking care of your body as you shed that fat—and the toxins that go along with it.

If you have more questions about whether fat loss can cause a toxin release, then leave your thoughts over at the Facebook.com/GetFitGuy page!

Detox image courtesy of Shutterstock.


All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Ben Greenfield

Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.