Carb Loading After Keto: What's Up With My Gut?

The ketogenic diet, commonly known as keto, is a low-carb, high-fat diet that switches the body's main fuel source from carbohydrates to fat. While this diet can lead to weight loss and improved insulin sensitivity, it can also cause digestive issues such as constipation, diarrhea, bloating, abdominal pain, and fatigue. These issues can arise when transitioning to or from the keto diet, as the body adjusts to the new fuel source. When reintroducing carbs after keto, some people may experience digestive issues due to carbohydrate intolerance, where the body has difficulty metabolizing carbohydrates, leading to symptoms such as abdominal pain, bloating, and fatigue.

Carbohydrate intolerance

The ketogenic diet, or keto, is a low-carb, high-fat diet that switches the body's fuel source from carbohydrates to fat. When carbs are eliminated from the diet, the body enters a metabolic state called ketosis, where it burns stored fat for energy. While this can lead to weight loss and improved insulin sensitivity, it also has some potential downsides, including gastrointestinal issues.

Causes of Carbohydrate Intolerance

Low-carb diets like keto can temporarily disrupt the body's glucose and insulin response, leading to carbohydrate intolerance or a more sensitive response to eating carbs. This occurs because the body becomes more efficient at using fat as fuel and less efficient at using carbohydrates. Keto may cause temporary insulin resistance and carbohydrate sensitivity, which can manifest as digestive issues when reintroducing carbs to the diet.

Symptoms of Carbohydrate Intolerance

Sensitivity to carbs can result in abdominal pain, bloating, gas, diarrhoea, constipation, and fatigue. These symptoms may be short-term while the body adjusts to the new diet or more long-term, lasting throughout the duration of the keto diet.

Relief from Carbohydrate Intolerance

There are several strategies to relieve the symptoms of carbohydrate intolerance:

• Eating more fibre: Fibre can help relieve constipation or diarrhoea.
• Eating less dairy: A keto diet may lead to a higher intake of dairy products, which can cause diarrhoea, bloating, and gas.
• Easing into the diet: A gradual transition to keto by slowly reducing carbs and increasing fats may help the body adapt better.
• Staying hydrated: Drinking plenty of water and sugar-free electrolyte beverages can help improve constipation and replace lost fluids and electrolytes.
• Adding probiotics and prebiotics: Probiotic supplements or probiotic- and prebiotic-rich foods may support gut bacteria and reduce gastrointestinal effects.
• Eating fermented foods: Fermented foods such as sauerkraut and kimchi can improve digestion and reduce constipation or diarrhoea.
• Reducing sugar substitutes: Cutting back on keto-friendly sugar substitutes may alleviate gastrointestinal symptoms.

It is important to consult with a healthcare professional before making any significant dietary changes and to seek medical attention for severe or persistent diarrhoea or constipation.

Insulin resistance

The ketogenic diet, or keto diet, is a popular eating pattern characterised by a significant reduction in carbohydrate intake and a concurrent increase in fat consumption. This shift in macronutrient ratios can have a profound impact on insulin sensitivity. Initially, the keto diet can improve insulin sensitivity and lead to favourable changes in blood sugar levels. This is one of the reasons why the keto diet has been touted as a potential approach for managing type 2 diabetes and improving metabolic health.

However, there is a flip side to this benefit. When transitioning to the keto diet, individuals may experience a period of temporary insulin resistance. This phenomenon is known as carbohydrate intolerance or carbohydrate sensitivity. As the body adapts to utilising fat as its primary fuel source, it becomes less efficient at processing carbohydrates. This reduced efficiency in handling carbohydrates can lead to digestive issues and other unpleasant symptoms.

Symptoms of carbohydrate intolerance can include abdominal pain, bloating, gas, diarrhoea, constipation, and fatigue. These symptoms are not just gastrointestinal; they can also affect your energy levels and overall well-being. It's important to note that these issues are typically temporary and usually subside as the body readjusts to utilising carbohydrates. This readjustment period can last for about two weeks for most people, but it may vary depending on the duration of the keto diet and individual factors.

To mitigate the impact of carbohydrate intolerance, it is recommended to gradually reintroduce carbohydrates. Start with a small increase in carbohydrate intake and slowly ramp it up over time. This gradual approach allows your body to reacclimate to carbohydrate metabolism and minimises the severity of digestive issues. Additionally, focusing on fibre-rich foods, staying hydrated, and incorporating physical activity can further aid in managing insulin resistance and its associated symptoms.

High-fat content

The keto diet is a high-fat, low-carbohydrate, and moderate-protein diet. It switches the body's main fuel source from carbohydrates to fat. This metabolic state is called ketosis, where the body burns stored fat for energy, leading to weight loss and improved insulin sensitivity.

The high-fat content of the keto diet may cause digestive issues due to the increased demand for bile production by the liver. As bile is a natural laxative, an excessive amount may push waste through the digestive tract faster than usual, leading to diarrhoea. The high-fat content can also cause other gastrointestinal symptoms such as nausea and bloating.

Additionally, the keto diet's restriction of carbohydrates may lead to a decrease in fibre intake, which can contribute to digestive issues. Fibre helps form stools and feeds the gut bacteria that control digestion. A sudden reduction in fibre intake can cause constipation.

To alleviate these potential issues, it is recommended to increase fibre intake, especially from whole foods and vegetables. Staying hydrated is also crucial, as dehydration is a common side effect of the keto diet and can contribute to digestive problems. Drinking water and sugar-free electrolyte beverages can help replace lost fluids and electrolytes.

It is important to note that these digestive issues may be temporary as the body adjusts to the high-fat content of the keto diet. However, some individuals may experience more persistent gastrointestinal problems, and it is advised to consult a healthcare professional if symptoms are severe, long-lasting, or painful.

Gut bacteria

When a person switches to a keto diet, the reduction in carbohydrates and increase in fats can cause an imbalance in the gut bacteria. This is because the gut bacteria that thrive on carbohydrates are no longer being fed their primary fuel source. Additionally, a high-fat diet may cause inflammation of the digestive tract, a decrease in healthy fatty acids, and other unfavourable changes in the gut microbiome. As a result, people often experience gastrointestinal issues such as constipation, diarrhoea, bloating, abdominal cramps, and pain.

To support gut health while on a keto diet, it is recommended to:

• Eat more fibre: Fibre-rich foods, such as vegetables, can help feed the gut bacteria and promote a healthy gut microbiome.
• Add probiotics and prebiotics: Probiotic supplements or probiotic-rich foods, such as sauerkraut and kimchi, can support the gut bacteria and improve digestion.
• Ease into the diet: Gradually reducing carbohydrates and increasing fats may give the body and the gut bacteria more time to adjust to the new diet, reducing potential gastrointestinal issues.
• Stay hydrated: Drinking plenty of water and staying hydrated is important for overall health and can help with constipation and other gastrointestinal issues.
• Reduce dairy intake: A keto diet may lead to an increase in dairy consumption, and a sudden increase in dairy can cause digestive issues for some people. Reducing dairy intake may help alleviate gastrointestinal symptoms.

It is important to note that everyone's gut bacteria and response to dietary changes are unique. While some people may experience gastrointestinal issues when reintroducing carbs after a period of keto, others may not. It is always recommended to consult with a healthcare professional or a qualified dietitian before making any significant dietary changes.

Dehydration

The keto diet also causes the body to produce ketones, which have a diuretic effect, making you urinate more. This is why people often refer to their initial weight loss on keto as "water weight".

As your body switches from using carbs for fuel to burning fat, the liver releases its glycogen stores. Glycogen is a form of glucose that is stored with lots of water, which exits the body through urine, leading to dehydration.

A low-carb diet also leads to lower insulin levels in the bloodstream. This signals the kidneys to excrete sodium at a higher rate. As sodium helps the body to retain water, lower sodium levels can cause the body to lose fluid.

The keto diet can also cause an imbalance of electrolytes, including sodium, potassium, and magnesium. This can lead to symptoms such as headaches, bad breath, muscle aches and pains, dizziness, dry mouth, and fatigue. If left untreated, dehydration can cause more serious issues such as kidney stones, urinary tract infections, and even kidney damage.

To avoid dehydration on the keto diet, it is recommended that you drink plenty of water and consume electrolytes from foods and beverages such as coconut water, broth, low-carb soup, bananas, cooked broccoli, seafood, tomatoes, pumpkin seeds, spinach, nuts, and dark chocolate.

Frequently asked questions