The ketogenic diet, more commonly called the keto diet, involves a severely restricted carbohydrate intake. People who follow the keto diet compensate for this reduction in carbohydrates by increasing their intake of high fat foods and eating moderate amounts of protein. These dietary adjustments can sometimes cause mild constipation. Keep reading to learn more about the keto diet, including how it may cause constipation and how to treat it.

What is a keto diet? Share on Pinterest The dietary adjustments of a keto diet may cause mild constipation. When people think of carbohydrates, they often picture grain-based foods, such as bread and pasta. Although it is true that eating too many simple carbohydrates, such as refined sugar, can negatively affect people’s overall health, carbohydrates exist in both healthful and unhealthful foods. The main types of carbohydrates in food include sugar, starch, and fiber, which are present in fruits, vegetables, and grains. The term carbohydrate refers to a group of molecules that cells can break down into a simple sugar called glucose. Glucose acts as the body’s primary source of energy because cells can easily convert it into adenosine triphosphate (ATP) through a process called glycolysis. People who follow the keto diet consume very small quantities of carbohydrates, usually limiting the intake to less than 50 grams (g) per day. This restricted intake means that their body will need an alternative source of energy. In the beginning, the body will tap into its glycogen stores. Glycogen is a larger, more complex form of glucose that the body metabolizes after it burns through all of the readily available glucose. When the body has exhausted its glycogen stores, the liver starts converting fatty acids into water-soluble molecules called ketone bodies. The cells can use these ketone bodies as an alternative source of energy when glucose is unavailable. When this happens, the body enters a state of ketosis.

Health risks of the keto diet Unfortunately, keto diets have their downfalls. People may find it difficult to sustain an extremely low carbohydrate diet for a long time. The transition into ketosis can also cause some undesirable side effects that may discourage people from sticking to the keto diet. Aside from fatigue and headaches, people may experience uncomfortable gastrointestinal (GI) symptoms. According to one large scale study on the use of keto diets to treat childhood epilepsy, nearly 50% of children experience the following GI symptoms during the first few weeks of starting a keto diet: constipation

vomiting

abdominal pain

Can a keto diet cause constipation? People who follow a keto diet may experience mild constipation that lasts a few days to a few weeks. According to the National Institute of Diabetes and Digestive and Kidney Diseases, people who have constipation often experience one or more of the following symptoms: fewer than three bowel movements per week

hard, dry, or lumpy stools

pain or difficulty passing stools

partially passing stool, which is called incomplete evacuation Reasons why someone might experience constipation while on a keto diet include: Transitioning too quickly Drastic changes to a person’s diet can negatively affect their digestive system and even cause symptoms, such as nausea or constipation. The body needs time to adjust to a diet. Gradually transitioning to a low carbohydrate diet over a few weeks may help prevent undesirable digestive side effects. Not eating enough fiber People who follow a keto diet usually consume 20–50 g of carbohydrates per day. This amount is much lower than the recommended daily value of 300 g of carbohydrates per day. Although people can benefit from limiting their intake of simple carbohydrates and processed foods, keto diets restrict all types of carbohydrate, including those present in high fiber fruits, vegetables, and grains. The digestive system cannot break down fiber, so it stays in the GI tract and adds bulk to stools by drawing water into the intestines. This added bulk and water helps keep stools soft and bowel movements regular. Without fiber, constipation may be more likely.

Treatment The side effects that occur when people transition to a keto diet should clear up once the body adjusts. However, these side effects may discourage people from continuing the diet. People who experience persistent constipation or have just started a keto diet may wish to consider the following treatments to manage their symptoms: staying hydrated

exercising regularly

walking after meals

eating high fiber, low carbohydrate foods, such as cauliflower, cabbage, and berries Read about 38 healthful high fiber foods here. If a person’s constipation does not improve after implementing these lifestyle and dietary changes, they can try using a low carbohydrate laxative, such as polyethylene glycol (MiraLAX). Fiber supplements can also help relieve constipation. However, these products may contain carbohydrates, which could impair the body’s ability to maintain ketosis. People should speak with a healthcare professional before starting a new medication or supplement.

Other possible side effects of a keto diet The transition to a keto diet can result in symptoms that resemble those of withdrawal, such as confusion, irritability, and increased sugar cravings. The normal balance of electrolytes and other minerals changes when the body stops using glucose as its primary source of energy and starts converting fat into ketone bodies. This imbalance can lead to flu-like symptoms, which people often refer to as keto flu. Some of these symptoms include: increased urination

dehydration

fatigue

lightheadedness

sweating

chills

nausea

muscle soreness

Preventing constipation on a keto diet The following tips may make the transition to a keto diet easier by lowering the risk of side effects, such as constipation and keto flu. When switching to a keto diet, people may find the following steps helpful: reducing daily carbohydrate intake gradually over a few weeks

drinking plenty of water

exercising regularly

avoiding simple carbohydrates

eating high fiber and low carbohydrate foods, such as vegetables, berries, and chia seeds

avoiding foods that may upset the digestive system, such as processed foods or fast food