Keto Stomach Pain: How Long Does It Last?

Stomach pain is a common side effect of the keto diet. The keto diet is a high-fat, low-carbohydrate diet that forces the body to burn fat for energy instead of carbohydrates. This transition can cause stomach pain, as well as other symptoms such as fatigue, muscle soreness, and nausea. The stomach pain is usually caused by dehydration and can be alleviated by drinking more water and adding more salt to your diet. The pain typically lasts a few days but can persist for several weeks.

Dehydration and keto

Dehydration is a common issue for people on the keto diet, which involves cutting carbs and eating fat. The keto diet puts the body into a metabolic state called ketosis, where the body burns fat instead of sugar for fuel. This shift can cause an electrolyte imbalance, leading to dehydration and other unpleasant symptoms.

When the body enters ketosis, the liver creates ketones—water-soluble compounds made of fatty acids that are released into the bloodstream and used as energy. Ketones have a diuretic effect, making you urinate more often and lose water. Additionally, as the body switches from using carbs for fuel, the liver releases its glycogen stores, which are stored with water and exit the body through urine, leading to further dehydration. A low-carb keto diet also leads to lower insulin levels, which signal the kidneys to excrete more sodium, causing the body to retain less water.

Signs of dehydration on keto

It's important to recognise the signs of dehydration, which include:

• Dry mouth and throat
• Fatigue and weakness
• Dizziness and lightheadedness
• Muscle cramps or spasms
• Confusion or brain fog

Preventing and combating dehydration on keto

• Drink more water: Aim for 2-3 litres of water per day, or at least half your body weight in ounces.
• Eat more electrolytes: Electrolytes are minerals that help the body retain water and include sodium, potassium, calcium, chloride, magnesium, phosphate, and bicarbonate. Eat more electrolyte-rich foods such as leafy greens, avocados, nuts, bananas, cooked broccoli, seafood, and tomatoes.
• Take an electrolyte supplement: Consider taking a keto-specific electrolyte supplement to ensure you're getting enough electrolytes.
• Eat water-rich whole foods: Choose low-carb, water-rich foods such as celery sticks, tomatoes, cucumber slices, berries, and lemons.
• Try infused water: Jazz up plain water by infusing it with fruits, herbs, or vegetables.
• Drink other hydrating liquids: In addition to water, drink low-sugar broths, juices, sports drinks, and popsicles.
• Avoid dehydrating substances: Limit alcohol and caffeine, as these can contribute to dehydration.

Lack of fibre in the diet

The keto diet is a low-carb, high-fat diet that limits daily non-fibre carbohydrate intake to 20 to 50 grams, compared to a typical carbohydrate intake of 150 to 250 grams. The keto diet is often criticized for its lack of fibre.

The keto diet can make it harder to get adequate amounts of essential nutrients, and this deficiency can impact health and comfort, making it difficult for some people to tolerate the diet. Many fibre-rich foods are also carb-heavy, so getting enough fibre on the keto diet can be difficult, leading to regularity challenges.

How Lack of Fibre Affects the Body

The body needs fibre to keep the digestive system healthy. Fibre passes through the body and keeps it regular by softening and adding bulk to stools. Fibre also feeds the good bacteria in the GI tract, aiding healthy digestion and nutrient absorption.

High-fat diets slow digestion and decrease GI motility, so it's especially important to get enough fibre. The keto diet can lead to constipation, poor digestion, and a lack of certain vitamins and minerals.

Tips to Get More Fibre on the Keto Diet

• Eat more fibre-rich foods, such as greens, cucumber, broccoli, cabbage, avocados, chia seeds, nuts, flax seeds, and low-carb berries.
• Drink more water and sugar-free electrolyte beverages to improve constipation and replace lost fluids and electrolytes.
• Take a probiotic supplement or increase the intake of probiotic- and prebiotic-rich foods to support gut bacteria.
• Eat fermented foods, such as sauerkraut and kimchi, to improve digestion and reduce constipation or diarrhea.
• Ease into the keto diet by slowly reducing carbs and increasing fats to help the body adapt better.
• Consult a healthcare professional or a registered dietitian knowledgeable about the keto diet to design a plan that meets your nutrient needs.

High-fat content

A ketogenic diet is high in fat, moderate in protein, and very low in carbohydrates. Stomach pain is a common side effect of the keto diet, especially in the initial stages. The high-fat content of the keto diet may cause stomach pain for some people. This is because the body is not used to breaking down and absorbing large amounts of fat.

The keto diet requires the liver to produce extra bile to break down fat. Bile is a natural laxative, so an excessive amount may cause diarrhoea. The high-fat content of the keto diet can also lead to other gastrointestinal symptoms, such as nausea and bloating.

To reduce the risk of experiencing stomach pain and other gastrointestinal issues, it is important to ensure adequate water intake. Water helps to improve constipation and can also help to replace fluids lost due to diarrhoea.

In addition to staying hydrated, it is recommended to eat more fibre-rich foods, such as non-starchy vegetables, to alleviate constipation. Taking a probiotic supplement or eating fermented foods, such as sauerkraut and kimchi, can also help improve digestion and reduce constipation or diarrhoea.

It is also important to note that the keto diet may not be suitable for everyone. It is always recommended to consult with a healthcare professional before making any significant dietary changes.

Stomach pain as a symptom of keto flu

Stomach pain is a common symptom of the keto flu, which is a collection of symptoms experienced by some people when they first start the keto diet. The keto flu is caused by the body adapting to a new diet consisting of very few carbohydrates.

The keto diet is a high-fat, moderate-protein, and very low-carbohydrate diet. This drastic reduction in carbohydrates can come as a shock to the body and may cause withdrawal-like symptoms, similar to those experienced when weaning off an addictive substance.

The symptoms of the keto flu can range from mild to severe and vary from person to person. Some people may experience stomach pain, while others may have diarrhea, fatigue, muscle soreness, or cravings. These symptoms typically last a few days or up to several weeks.

There are several ways to ease the symptoms of the keto flu and help your body get through the transition period:

• Drink plenty of water to stay hydrated and reduce the risk of dehydration, which is a common side effect of the keto diet.
• Replace electrolytes, such as sodium, potassium, and magnesium, which can be lost due to increased urination and reduced insulin levels on the keto diet.
• Get enough rest and avoid strenuous activities, as fatigue and muscle cramps are common during the first week of the keto diet.
• Make sure you are eating enough fat, as this is the primary fuel source on the keto diet.
• Cut back on carbs slowly over time, rather than all at once, to give your body time to adjust.

While the keto flu can be uncomfortable, the symptoms are usually temporary and will gradually decrease as your body gets used to converting ketones into energy. However, if you are experiencing severe or persistent symptoms, it is best to consult your doctor.

Diarrhoea and constipation

The keto diet can lead to gastrointestinal (GI) problems, such as diarrhoea and constipation, as your body adjusts to this new way of eating. These GI issues can be short-term or long-term and can last the duration of the keto diet.

Causes of Diarrhoea and Constipation on the Keto Diet

The standard American diet is high in carbohydrates, so switching to a keto diet is a drastic change. The keto diet is high in fat (70-80%), moderate in protein, and very low in carbs. The recommended daily carb intake on the keto diet is 20-50 grams, whereas the Dietary Guidelines recommend 225-325 grams of carbs based on a 2,000-calorie diet.

The biggest issue with the keto diet is the lack of fibre, which can lead to constipation. Fibre is important for colonic health and helps the colon function better. Fibre-rich foods like fruits, whole grains, and legumes are restricted on the keto diet, making it challenging to get enough fibre.

Another potential problem is acid reflux. Fats take longer to empty out of the stomach, so they keep people fuller for longer. On the keto diet, delayed stomach emptying may leave your stomach feeling full all the time, triggering abdominal discomfort and an increased risk of regurgitation and heartburn.

Additionally, there may be a delay in enzymes that digest fat, responding to the increasing amount of fat in your diet. If fat isn't broken down in the small intestine, it travels to the colon, where bacteria can lead to gas, bloating, and fat in the stool, causing looser stools or diarrhoea.

Tips to Relieve Diarrhoea and Constipation

• Eat more fibre: Fibre can help relieve constipation or diarrhoea. High-fibre, keto-friendly foods include greens, cucumbers, broccoli, cabbage, avocados, and nuts.
• Eat less dairy: The keto diet may lead to an increased consumption of dairy products, which are high in fat. This dietary change may reveal an intolerance to dairy, with common symptoms including diarrhoea, bloating, and gas.
• Ease into the diet: A sudden change in diet may disrupt GI bacteria. Gradually reducing carbs and increasing fats may help your body adapt better.
• Stay hydrated: Drinking water and sugar-free electrolyte beverages can help replace fluids and electrolytes lost due to diarrhoea.
• Add probiotics and prebiotics: Taking a probiotic supplement or increasing probiotic- and prebiotic-rich foods may support gut bacteria and reduce GI effects.
• Eat fermented foods: Eating fermented foods like sauerkraut and kimchi can help improve digestion and reduce constipation or diarrhoea.
• Decrease intake of sugar substitutes: Cutting back on keto-friendly sugar substitutes may help relieve gastrointestinal symptoms.

When to See a Doctor

If you experience severe or persistent diarrhoea or constipation, it is important to consult a doctor. Severe abdominal pain, diarrhoea that occurs more than six times a day, or constipation that lasts longer than a week are warning signs that require medical attention.

Additionally, if you are new to the keto diet and your constipation or diarrhoea persists for more than two to three weeks, it is recommended to see a doctor to ensure there are no underlying issues.

Frequently asked questions