Keto Diarrhea: What You Need To Know

The keto diet is a high-fat, low-carb, and moderate-protein eating plan that has gained popularity for its ability to induce quick weight loss. However, it has also led to an unfortunate side effect: keto diarrhea. This condition is characterised by loose, watery stools and can be attributed to several factors, including increased fat intake, decreased fiber intake, and changes in gut bacteria. While not everyone experiences diarrhea on keto, it is a common issue, especially during the initial phase of the diet. In this article, we will explore the causes and provide insights into managing and preventing this unpleasant symptom.

High-fat content

The keto diet is a high-fat, low-carbohydrate, and moderate-protein diet. The diet typically consists of 65-90% fat, with some sources suggesting 70-80% or even 70-75% of calories from fat. This high-fat content can lead to keto diarrhea, a common side effect of the diet.

The body struggles to break down and absorb the large amount of fat consumed on the keto diet, which can lead to malabsorption. This means that some of the fat is not properly broken down and absorbed by the body, leading to greasy stools that are loose and watery. This is particularly common in people who have had their gallbladder removed or who do not produce enough bile, which is necessary for fat absorption.

The liver has to produce extra bile to break down the fat consumed on the keto diet. This can lead to an increased amount of bile in the intestines, which acts as a natural laxative. The partially digested food and bile then move through the intestines and colon more rapidly, resulting in reduced transit time. This decrease in transit time leads to less water being reabsorbed from the waste before it is excreted, resulting in runny or loose stools.

Additionally, the high-fat content of the keto diet can lead to feelings of bloating and nausea, as well as gas pains and excessive flatulence. This is because the extra bile production and increased intestinal peristalsis can cause these unpleasant side effects.

To help alleviate keto diarrhea caused by the high-fat content, it is recommended to reduce the amount of fat consumed and introduce more vegetables into the diet. Staying well-hydrated and increasing water and electrolyte intake are also important to manage these symptoms.

Artificial sweeteners

The ketogenic diet is a high-fat, low-carbohydrate, and moderate-protein diet. It involves consuming 70-80% of calories from fat, 10-30% from protein, and less than 5-10% from carbohydrates. This shift in metabolism is known as ketosis, where the body burns fat instead of glucose for energy.

One of the common side effects of the keto diet is diarrhea, which can be caused by various factors, including the high-fat content, low fiber intake, and changes in gut bacteria. Artificial sweeteners, specifically non-nutritive sweeteners and sugar alcohols, have also been identified as a potential cause of keto diarrhea.

Non-Nutritive Sweeteners

Non-nutritive sweeteners, such as aspartame, Splenda, sorbitol, maltitol, xylitol, and sucralose, are often used as sugar substitutes on the keto diet. These artificial sweeteners are not effectively absorbed in the gut and can reach the large intestine undigested. As a result, they can have a laxative effect, leading to diarrhea and other gastrointestinal issues.

Sugar Alcohols

Sugar alcohols, including erythritol, mannitol, xylitol, sorbitol, maltitol, lactitol, and isomalt, are commonly found in keto-friendly products like cereals, protein bars, and yogurt. These sugar substitutes are known to cause digestive distress and have been shown to have a laxative effect, leading to diarrhea, bloating, gas, and nausea.

Impact on Gut Bacteria

The keto diet's restriction of carbohydrates and fiber-rich foods can also affect the gut microbiome by decreasing the abundance of good bacteria. This disruption in the gut microbiome can lead to gut-related problems, including diarrhea and inflammation in the gut.

Preventing and Managing Keto Diarrhea

To prevent and manage keto diarrhea caused by artificial sweeteners, it is recommended to:

• Reduce the consumption of artificially sweetened foods and sugar-free products.
• Increase water and electrolyte intake to stay hydrated.
• Introduce more vegetables and high-fiber foods to your diet.
• Add insoluble fiber, such as psyllium, to your diet.
• Consume probiotic-rich foods like yogurt, kefir, kimchi, and kombucha.
• Consult with a registered dietitian to ensure your nutritional needs are met.

It is important to note that keto diarrhea usually resolves with time as your body adjusts to the diet. However, if diarrhea persists or becomes severe, it is recommended to seek medical advice.

Dairy products

If you suspect dairy products are causing your keto diarrhea, consider switching to plant-based, vegan alternatives such as cashew cheese, hemp milk, almond milk, coconut yoghurt, and coconut milk. Eliminating dairy may help alleviate the issue.

It is worth noting that some full-fat dairy products, such as butter, are naturally low in lactose, as the "fat" portion of dairy does not contain lactose. However, other dairy products like whole milk, full-fat yoghurt, and cheese do contain lactose and can trigger digestive issues.

Additionally, if you are experiencing keto diarrhea, it is important to stay hydrated and replenish electrolytes. While dairy products can be a source of hydration, they may not be the best option if they are causing digestive problems.

Disruption of the gut microbiome

The gut microbiome refers to the microorganisms in the gastrointestinal tract. The gut microbiome is made up of bacteria, viruses, fungi, and protozoa. The gut microbiome is important for health in many ways, including helping the body with digestion and improving immune function.

The keto diet can cause disruptions to the gut microbiome, which can lead to diarrhea. Firstly, the keto diet is low in fiber, which is essential for digestion and maintaining bowel regularity. Insufficient fiber intake can lead to an increased risk of constipation.

Secondly, the keto diet can alter the gut microbiome by reducing the diversity of bacteria in the gut and increasing inflammation. A high-fat diet has been found to reduce the number of beneficial bacteria in the gut and increase the number of Bacteroides, which are associated with inflammatory bowel disease, severe antibiotic-resistant infections, and colorectal cancer.

Thirdly, the keto diet can lead to an overgrowth of certain types of bacteria, such as Desulfovibrio, which are associated with gut inflammation and the development of inflammatory bowel disease.

Finally, the keto diet can cause issues with digesting fat. Some people may have trouble digesting large amounts of fat and may experience slight malabsorption diarrhea.

To relieve the symptoms of diarrhea caused by the keto diet, it is recommended to eat more fiber, take probiotic supplements, and ease into the diet. Staying hydrated and drinking water and sugar-free electrolyte beverages can also help relieve diarrhea.

Lack of fibre

The keto diet is very low in carbohydrates, which means that you're likely eating less fibre. Fibre comes from carbs like fruits, legumes, starchy foods, and grains. Fibre is important for colonic health and promotes the growth of good bacteria in the gut. A decrease in fibre intake can lead to constipation and other gut-related problems like changes to the gut microbiome and inflammation in the gut.

According to Harvard Health Publishing, American adults consume an average of 10 to 15 grams of fibre per day, while the goal for people up to age 50 is 25 grams of fibre for women and 38 grams of fibre for men each day.

The keto diet restricts many fibre-rich foods, such as fruit, vegetables, whole grains, and legumes. This can lead to a lack of fibre in the diet, which can cause constipation. Lindsey Albenberg, DO, a gastroenterologist at the Children's Hospital of Philadelphia in Pennsylvania, says that "a high-fiber diet promotes diversity in the gut microbiome that's been associated with health".

If you're experiencing constipation on the keto diet, you can try adding more fibre-rich, keto-friendly foods to your diet, such as non-starchy vegetables like broccoli and artichokes, or fat sources like avocado and nuts. You can also try taking a fibre supplement, but it's important to note that it's difficult to get all the fibre you need from supplements alone.

In addition to constipation, a lack of fibre can also contribute to other gastrointestinal issues, such as diarrhoea. Fibre adds bulk to the stool and helps the colon work like a muscle to move things through more easily. Without enough fibre, the stool can become loose and watery, leading to diarrhoea.

If you're experiencing diarrhoea on the keto diet, increasing your fibre intake may help to bulk up your stool and reduce bathroom trips. However, it's important to note that taking an anti-diarrhoeal medication like Imodium will only temporarily pause your bowels and will not fix the root cause of the problem.

Overall, a lack of fibre in the keto diet can lead to both constipation and diarrhoea, and it's important to take steps to ensure you're getting enough fibre to support your gastrointestinal health.

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