Does Having Diarrhea Burn Calories? (Explained)


Diarrhea can be a real nuisance, and unfortunately, most individuals will have it once or twice annually. Most of the time, it goes away within a few days. You might be wondering if having diarrhea burns calories and if so, can it boost weight loss?

The short answer is that diarrhea does burn calories as part of an increased basal metabolic rate, but it should not be used as a weight loss tool. You may lose weight as a result of fluid volume loss or decrease in overall caloric intake.

You can easily manage diarrhea symptoms by hydrating, resting, and making specific adjustments to your diet to replenish nutrients lost.

Let’s talk some more about it.

Does Having Diarrhea Burn Calories?

Diarrhea does burn additional calories, but these calories are part of your basal metabolic rate and are not considered additional active calories burned. Your basal metabolic rate may increase as a result of diarrhea and increased GI function.

However, when you’re experiencing diarrhea continuously for days, you will lose a significant amount of body fluids.

The body fluids lost might reveal a loss of weight on the scale, but this is usually not due to a loss in body fat. It is due to a decrease in overall fluid volume.

Diarrhea can become a problem if it continues and can cause you to become quite dehydrated, so it is important to replenish fluids lost through diarrhea.

Additionally, diarrhea can be associated with other symptoms, like loss of appetite and nausea, which make it difficult to replenish the nutrients already lost from your body.

If you are not consuming as many calories over an extended period of time do to illness causing diarrhea, there is a chance you will lose body fat as you are increasing your overall caloric deficit.

This decreases your body’s calorie intake, which could result in the loss of body fat.

Depending on the duration the diarrhea lasts and the seriousness of the symptoms, the weight loss can be substantial in severe cases.

This is not a positive weight loss, and can be quite dangerous as you are also likely causing a loss of important nutrients and electrolytes.

Nonetheless, any weight loss as a result of short lived diarrhea is mostly water weight, and you’ll restore it when your appetite and bowel movements become normal.

Common Causes of Diarrhea

One of the most common causes of diarrhea is Escherichia Coli, It is also commonly called E. coli for short and is a common cause of Traveler’s diarrhea.

Another common diarrhea cause is Salmonella. This bacterium can trigger typhoid and intestinal fever. Besides this, it is the culprit behind food poisoning.

Third is rotavirus, which is mostly a cause of diarrhea in children. It causes severe stomach pain and vomiting in infants below six months.

Further, when it comes to diarrhea in adults, Campylobacter jejuni can be a culprit. It is also called campylobacteriosis.

Campylobacter jejuni resides in the intestines, though it is also present in raw foods like raw chicken and hamburgers. It can access your body through open wounds like a cut on the skin from shaving or cutting yourself by mistake.

Lastly, the other common cause of this condition is Shigella. This bacterium triggers diarrhea, accompanied by symptoms like vomiting and severe stomach pain.

Bacteria does not always have to have a bacterial cause. Sometimes, a virus is the cause. For example, adenovirus and Norwalk virus can lead to viral gastroenteritis or stomach flu.

This condition is characterized by vomiting, watery stool, nausea, and diarrhea for about 24-48 hours. After that, it goes away on its own.

Other less common causes of diarrhea are:

  • Parasites: These include amoeba and giardia. They are often found in contaminated water and can cause severe diarrhea, dehydration, weight loss, and malnutrition.
  • Food intolerance: Some people have trouble digesting lactose, gluten, fructose, or sugar alcohols. This can lead to bloating, gas, and diarrhea.
  • Medications: Some antibiotics can kill the good bacteria in your gut along with the bad bacteria. This can lead to diarrhea caused by a spore called clostridium difficile. Other medications that can cause this include antacids, cancer treatments, and heart medications.
  • Celiac disease: This is an autoimmune disorder that damages the small intestine. It is caused by consuming gluten.
  • Inflammatory bowel disease (IBD): This includes Crohn’s disease and ulcerative colitis. They are chronic conditions that can cause abdominal pain, weight loss, and diarrhea.
  • Irritable bowel syndrome (IBS): This is a common condition that affects the large intestine. It can cause bloating, gas, abdominal pain, and diarrhea.

How Does Diarrhea Burn Calories?

Having diarrhea can cause your body burn on average a few hundred extra calories, though it varies from person to person and should not be relied on as a weight loss tool.

Diarrhea causes frequent trips to the bathroom due to the fact that the body is not able to absorb the water contents of food and fluids consumed.

Also, diarrhea is frequent because the intestines are contracting more frequently to push the stool out and the speed at which your digestive system is working is increased.

This means foods you may eat are often are not completely broken down, which causes stomach acids, certain digestive enzymes, and bile to be present in diarrhea.

These can cause a burning sensation in the rectum during or after a bowel movement and cause irritation.

All these contractions and increased digestive system function increase calories burned as part of the body’s basal metabolic rate.

Do You Lose Nutrients When You Have Diarrhea?

Yes. You will lose nutrients as well as electrolytes as diarrhea will make your body pass food nutrients through quicker than it absorbs them.

All the same, the huge problem with diarrhea is usually dehydration due to the fact that you are losing fluids present in watery diarrhea.

So, you will lose nutrients that aren’t absorbed, those eliminated from the body, and plenty of fluids.

Related Post: How Many Calories Does The Body Absorb In One Sitting?

In addition to causing fluid and electrolyte loss, severe diarrhea has considerable negative effects on your nutritional status.

Does Diarrhea Reverse the Calories You Already Ate?

No. While it is true nutrient and calorie absorption will be altered, you will still absorb calories and what you consume will not be completely reversed.

Absorption of nutrients takes place in the small intestine, where plenty of water taken from different organs is combined with the food to create chyme.

Once a huge part of the nutrients is absorbed via the small intestine’s surface, the loose-textured chyme goes into the large intestine.

One of the many roles of the large intestine is to absorb the water out of the chyme once more. If there are any issues during this process, this is when diarrhea will occur.

Diarrhea linked to poor absorption of nutrients in the small intestine, though this isn’t a sure indicator that many of your calories eaten will be undone.


Having diarrhea does burn calories as part of your basal metabolic rate and this rate may be increased, which includes increasing the calories burned during normal body processes.

Diarrhea should not be relied upon as a weight loss tool. It is dangerous and not a reliable way to lose weight.

Continued diarrhea over time can actually be very dangerous, so it is important to not induce diarrhea as a means of weight loss.

If you do have diarrhea, it is important to make sure you are replacing the body fluids lost in the process of frequent bathroom trips as well as nutrients and electrolytes.

If you are sick and continue to have diarrhea that does not resolve on its own, you should speak to a medical professional to seek out a cause.