Talkin’ Crap: How Keto Effects Bowel Movements

 In Fitness Center Southlake

ketoYou read the title correctly, we’re talking crap. Not figuratively, literally. The fact that you opened this article tells me you’re either doing keto and you’ve noticed some “irregularities” in your normal routine or you’re a curious person with a sense of humor. Either way, you must be pretty cool. No matter why you’re reading this you’re going to learn some very relevant information on the ketogenic diet and how it affects your gut… and butt. Sorry, I couldn’t resist.

Before I proceed it’s important you understand what a keto is. Keto is a very high-fat, low-to-moderate protein, low-carb diet. Keto simulates fasting physiology and essentially tricks your body in to fat burning mode. For more detailed information about the science of a keto diet check out Amanda Fletcher’s last blog. There’s one critical detail you need to know

Pop quiz: Where does fat go when you burn it?

If you’re like most people (including 90% of doctors, dieticians and nutritionists recently polled) you probably guessed you excrete it out through bowel movements, urination, sweat, etc…

Nope! When you burn fat, you’re left with two byproducts, carbon dioxide (CO2) and water (H20). To be more precise 84% CO2 and 16% H20. And how do we get rid of carbon dioxide? We get rid of carbon dioxide through breathing! Let me say that again, when you burn fat it turns in to CO2 you exhale it out. I love crazy facts like that.

The remaining 16% water is excreted through various means, such as sweat, urination, tears and so on. This further explains why people following a ketogenic diet tend to urinate more and have fewer bowel movements.

What this means when you’re eating keto

When you’re eating a more standard diet all that protein and carbohydrate is broken down into more solid waste products (fecal matter) that must be excreted through your bowel movements. Keto is pretty darn low in those macronutrients which means you produce less solid waste. Namely, less poo.
Keto diets generally vary between 70%-90% of all calories coming from fat. Since we know that the main byproduct of burned fat is CO2, which we breathe out, you now understand why you’re not quite as regular as you used to be.

Pretty simple, you’re exhaling the waste instead of passing it out the other end. This is why diet and exercise are the most effective combination for weight loss. You’re taking in less CO2 and exhaling more CO2 due to elevated respiration rates.

Putting it all together

If you’re on a ketogenic diet and you’ve noticed these changes. Now you know why. If you’re considering doing keto now you know what to expect.

However, if you are genuinely constipated, not just going less frequently, I highly suggest you consider your water intake. If you are not getting enough water YOU WILL become constipated. Drink water. It’s good for you. I promise. You may also consider trying Smooth Move Tea. It can be highly effective. If those fail to deliver the desired result seek a medical professional for the appropriate care.

In summary, when you’re doing keto you will do more #1 and less #2 generally. That is normal.

So, take a deep breath and relax knowing you just helped release a little more fat and are very likely ok.  You’re just kinda pooing through your mouth instead.


When somebody loses weight, where does the fat go?

Hirsch J, Farquhar JW, Ahrens EH, Jr, Peterson ML, Stoffel W. Studies of adipose tissue in man. A microtechnic for sampling and analysis. Am J Clin Nutr1960;8:499-511

Hodson L, Skeaff CM, Fielding BA. The fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake. Prog Lipid Res2008;47:348-80

Lifson N, Gordon GB, Visscher MB, Nier AO. The fate of utilized molecular oxygen and the source of the oxygen of respiratory carbon dioxide, studied with the aid of heavy oxygen. J Biol Chem

Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett DR, Jr, Tudor-Locke C, et al. 2011 Compendium of physical activities: a second update of codes and MET values. Med Sci Sports Exerc 2011;43:1575-81



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