7 Important Keto Diet Side Effects: Everything You Need To Know

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The ketogenic diet, commonly known as “keto,” or “keto diet,” is just one of several weight-loss eating diets. While it might assist in weight loss, some keto diet side effects and complications might appear which can include complications like diarrhea, mineral deficiencies, or a decrease in athletic performance.

As the body enters a state of ketosis, which is triggered by reducing daily carbohydrate intake to 50g (grams) or less, individuals may encounter these effects. During ketosis, the body shifts to burning fat instead of sugar for energy. Here’s everything you need to know.

Possible negative keto diet side effects

Making significant changes to how you eat can have effects beyond just changes in weight. For individuals following the keto diet, doing it incorrectly or sticking with it for too long may raise the risk of experiencing side effects such as kidney stones or deficiencies in essential nutrients.

1. Dehydration

Following this diet may result in individuals losing water weight before burning fat, potentially leading to dehydration as one of the initial side effects of ketogenic diets.

Dehydration happens when your body loses more fluid than it takes in. Symptoms of dehydration can include:

  • Changes in urine, like dark-colored urine
  • Dizziness
  • Dry mouth
  • Increased thirst
  • Tiredness

2. Gastrointestinal issues

Frequent gastrointestinal (GI) issues, such as constipation, diarrhea, nausea, or vomiting, are typical side effects of a keto diet. Among these, diarrhea occurs more often, possibly due to the having difficulty absorbing the increased fat content present in the diet.

3. Kidney stones

Following the keto diet might increase the risk of developing kidney stones, which are mineral-based formations in the kidneys.

According to this review, individuals without kidney disease, the keto diet may elevate the likelihood of kidney stone formation due to its focus on animal-based and high-fat foods, as noted in a review. For those with pre-existing kidney issues, following the keto diet could aggravate long-term kidney damage and worsen metabolic acidosis. The review also highlights the potential role of ketoacidosis in the development of kidney stones, attributed to decreased citrate and pH levels, coupled with increased calcium levels in the urine.

What Is Ketoacidosis?

Ketoacidosis happens when an excess of ketones, acidic byproducts produced during fat metabolism, build up in the bloodstream. These ketones cause an increase in blood acidity and may spill over into your urine.

For individuals with type 1 diabetes, ketosis can trigger ketoacidosis due to insufficient insulin for glucose utilization. It is crucial to seek immediate medical attention if signs of ketoacidosis manifest, as the condition can be fatal if left untreated.

4. Reduced athletic performance

Athletes might view the ketogenic diet as beneficial for weight loss and enhanced sports performance. Nonetheless, a study revealed that individuals performed less effectively in high-intensity cycling and running tasks after four days on a ketogenic diet compared to those who followed a high-carb diet for the same duration.

5. The “Keto-flu”

Following the keto diet can trigger the onset of the keto flu for some individuals, characterized by symptoms like:

  • Constipation
  • Dizziness
  • Exercise tolerance difficulties
  • Fatigue
  • Headache
  • Insomnia
  • Nausea or vomiting

To minimize the impact of the keto flu, consider maintaining proper hydration, increasing electrolyte intake, gradually reducing carbohydrate consumption, and taking a gradual approach to adopting the diet.

6. Vitamin and mineral deficiencies

To maintain low carb intake on the keto diet, many fruits and vegetables may be restricted or excluded. This limitation can result in a reduced consumption of crucial nutrients, including:

  • Calcium
  • Fiber
  • Iron
  • Magnesium
  • Potassium
  • Various vitamins

Notably, individuals following the keto diet may also have lower intake of folate, thiamin, as well as vitamins A, B6, B12, C, E, and K. These vitamins play essential roles in various bodily functions, including bone health, gum health, metabolism, red blood cell production, and more.

7. Weight regain

Due to the restrictive nature of the keto diet, individuals may experience weight regain upon returning to their initial eating patterns. This is partly attributed to the challenges of sustaining the diet over an extended period.

Recommended duration for following the keto diet range from two to three weeks up to 12 months. If you’re considering the keto diet, seeking guidance from a dietitian is advisable for personalized advice.

Potential benefits of the keto diet

Despite the less desirable keto diet side effects, there’s a possibility of experiencing positive effects on both your physical and mental health.

Appetite control

The keto diet can contribute to appetite regulation by impacting ghrelin, the hunger-signaling hormone. In other words ghrelin tells you if you are hungry. Typically, weight loss from dieting leads to increased ghrelin secretion, but during ketosis, this hormonal response tends to decrease.

According to researchers, during the first six to 12 months of adopting the diet, individuals may observe reductions in blood pressure, blood sugar, and triglyceride levels. Additionally, there might be an increase in high-density lipoprotein (HDL) cholesterol, commonly known as good cholesterol.

Emotional and cognitive changes

Studies have indicated the potential effectiveness of the keto diet in addressing certain mental health and cognitive conditions or symptoms. A review revealed that the diet was linked to improvements in symptoms related to:

  • Anxiety
  • Auditory and visual hallucinations
  • Cognition
  • Communication skills
  • Energy levels
  • General mood

Despite the positive findings in the review, researchers emphasized the need for more comprehensive research to further understand the benefits of the keto diet for mental health conditions.

Seizure frequency reduction

Beyond weight loss, the keto diet exhibits positive effects. With a history of over a century, keto diets have been utilized in the treatment of epilepsy, proving effective in decreasing the frequency of seizures in individuals with drug-resistant epilepsy while also contributing to weight reduction.

Who should avoid the keto diet?

People with the following conditions are advised to avoid the keto diet:

  • Eating disorders or a history of such disorders
  • Fat metabolism disorders (e.g., disorders of fat storage)
  • Gallbladder disease
  • Liver failure or other liver conditions
  • Pancreatitis
  • Thyroid problems, such as hypothyroidism

For individuals diagnosed with diabetes and prescribed insulin or hypoglycemic medications, it is crucial to consult with a healthcare provider before following this diet. Failure to make appropriate medication adjustments beforehand may result in severe hypoglycemia.

Is the keto diet healthy?

The keto diet can have positive aspects. Despite its emphasis on high-fat and low-carb foods, it allows moderate protein consumption, essential for building body structures such as bones, skin, and hormones.

Research has demonstrated the potential benefits of the keto diet for individuals dealing with neurological disorders like dementia or epilepsy, as well as those struggling with overweight or obesity.

However, following the keto diet may have adverse effects due to its focus on high-fat content. Increased consumption of saturated fat-rich foods like beef, pork, cheese, and butter can elevate low-density lipoprotein (LDL) cholesterol levels. Higher LDL cholesterol levels are associated with an increased risk of heart disease or strokes.

A quick review

Some keto diet side effects are dehydration, ketoacidosis, and the keto flu. It’s not suitable for everyone, particularly individuals with kidney or liver problems. However, for those who can follow the keto diet, there may be benefits beyond weight loss, such as improvements in blood sugar, good cholesterol, or mood. It’s advisable to consult with a registered dietitian to ensure you receive adequate nutrients.

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