What If the Keto Diet Causes Diarrhea
Keto Diet

What If the Keto Diet Causes Diarrhea?

Almost everyone who starts on a keto diet will experience side effects to varying degrees. This is because when you change your diet, your body takes some time to adapt, and during this process, you will more or less experience some uncomfortable feelings. One of the more common symptoms is frequent diarrhea. Today we’ll talk about why the keto diet can cause gastrointestinal problems and how to solve them.

What is a Keto Diet?

The keto diet is a very low-carb diet that has become popular around the world in recent years because it is very fast and effective. The nutritional ratio of the keto diet is 5% carbohydrates, 20% protein, and 75% fat.

Its mechanism of action is to put your body into a metabolic state called ketosis, where your body breaks down and burns stored fat as a source of energy instead of glucose. Studies have found that the keto diet can successfully aid weight loss by improving lipid-protection oxidation, the body’s process of breaking down fatty acids. It also has a positive effect on blood sugar levels and insulin resistance.

However, when first changing from a traditional high-carb diet to a very low-carb diet, many people experience adverse reactions, such as:

  • Headaches
  • insomnia
  • Constipation
  • Diarrhea
  • bloating
  • Hair loss
  • Bad breath

These symptoms will disappear once your body has fully adapted to the new way of eating, generally, this process is between a few and ten days, depending on the individual’s body condition. Also, if your body goes off ketones during this adaptation process, it can prolong the duration of the adverse reaction.

Causes of Diarrhea

Any extreme change in diet can affect the gastrointestinal tract. A keto diet requires strict carbohydrate restriction and eating a lot of fat so that you can stay in a state of ketosis. However, some people find it difficult for their bodies to adjust to such a high-fat content and are likely to experience diarrhea and diarrhea.

Keto Diet Causes Diarrhea

Causes of This Reaction Include

Intestinal Flora Imbalance

The microbiota in the gut plays an important role in health, with beneficial bacteria that help the body absorb nutrients. When you have a significant change in the structure of your diet, such as a significant reduction in carbohydrates, the intestinal flora will be out of balance.

In a traditional diet, gastrointestinal microbes feed on the short-chain lipid-proof acids found in grains, fruits, and vegetables, and the keto diet limits this short-chain lipid acid. As long as the keto diet continues, the gut flora will gradually adapt and adjust accordingly to return to the original balance, but you will still experience some of the discomfort known as “keto flu” during this process.

Inability to Absorb Fat

Fats require a lot of work to be broken down by the body, and some people are simply not used to metabolizing the fats in a keto diet. When you consume too much fat, if your body can’t keep up with the rate of breakdown and absorption, the unabsorbed fat will enter the small intestine and colon and absorb more water to help it pass, resulting in watery diarrhea. A small number of people who follow a keto diet will always have diarrhea problems because their bodies cannot absorb and use all the fat.

Excessive Bile Fraction

The liver secretes bile to break down fat, and a high-fat diet requires more bile. Since bile is a natural laxative, too much bile may push waste into the digestive tract faster than usual, leading to diarrhea. The high fat and low carbohydrate content of the keto diet may also lead to other gastrointestinal symptoms, such as nausea and bloating.

Non-Nutritive Sweeteners

Many people who follow a keto diet avoid nutritional sugars, including added sugars and fructose. Instead, they choose artificial sweeteners and sugar alcohols, such as aspartame, sucralose, sorbitol, maltitol, and xylitol. Studies have found that excessive amounts of sweeteners have a laxative effect and can cause diarrhea. Sugar alcohol sweeteners are difficult to absorb and often enter the large intestine undigested, causing adverse effects such as bloating, abdominal pain, and diarrhea.

How to Relieve Keto Diarrhea?

If you experience gastrointestinal problems after starting a keto diet, try these options to relieve symptoms.

  • Drink more water – Diarrhea in the early stages of keto causes the body to lose a lot of water, which can worsen the symptoms of keto flu. Drinking plenty of plain or lightly salted water can help replenish fluids and lost electrolytes.
  • Eat more dietary fiber – Fiber can help relieve constipation or diarrhea. Eat more low-carb, high-fiber foods such as leafy greens, broccoli, cabbage, certain seeds, and nuts.
  • Eat less dairy – Many people are lactose intolerant and dairy products can cause gastrointestinal discomfort. Cut back on these types of foods and see if the diarrhea problem resolves.
  • Eat more fermented foods – Fermented foods such as sauerkraut and kimchi help improve digestion and may reduce gastrointestinal symptoms such as constipation or diarrhea.
  • Add probiotics and prebiotics – Taking probiotic supplements or eating more prebiotic-rich foods, such as apples, walnuts, and onions, can promote balanced intestinal flora and help reduce the effects of a keto diet on the gastrointestinal tract.
  • Reduce non-nutritive sweeteners – Minimizing the intake of foods and beverages containing artificial sweeteners and sugar alcohols can help relieve diarrhea.
  • Gradually increase fats – Sudden changes in diet can lead to imbalances in the intestinal flora and cause digestive problems such as diarrhea. Try slowly reducing carbohydrates and gradually increasing fats to ease the burden on the gut and help the body better adapt to the new diet.

If the diarrhea is severe or lasts longer than a week, you should seek medical attention as soon as possible. Or maybe this diet isn’t for you and consider trying other ways to lose weight.


The keto diet requires strict carbohydrate restriction and a high intake of fat so that the body can stay in ketosis and thus burn fat quickly. However, a sudden change in diet can lead to digestive problems such as constipation and diarrhea, which is one of the adverse effects of keto. Steps can be taken to alleviate symptoms, such as eating more fiber, replenishing electrolytes, adding probiotics, and reducing the amount of fat to help the body better adapt and transition to the new diet.