If you have ever dealt with sudden, severe leg pain on the ketogenic diet, you’re not alone.

Although this high fat, low carb diet may aid weight loss and even help treat certain medical conditions, it has been associated with a number of side effects — including leg cramps.

This article explains why some people may experience leg cramps on keto and offers tips for treating and preventing this uncomfortable side effect.

Cramps are involuntary, localized muscle contractions that are often painful. Leg cramps typically affect the calf muscle, though they can occur in other parts of your leg as well (1).

These contractions commonly occur at night and can last seconds to minutes. Most leg cramps are over in less than a few minutes (1).

Although their exact cause isn’t always clear, multiple factors, including pregnancy, medical treatments, insufficient blood flow, and the use of certain drugs, may increase your risk.

The keto diet may make you more susceptible to leg cramps for several reasons (2).

Too little electrolytes

A potential cause of leg cramps is an electrolyte imbalance.

Electrolytes are minerals that are essential for critical functions in your body, such as cell communication. They include sodium, magnesium, chloride, potassium, calcium, phosphate, and bicarbonates (3).

If your levels become depleted, your nerve cells may become more sensitive. In turn, this leads to pressure on nerve endings, which may cause muscle spasms (4).

When adapting to the keto diet, your body may lose more electrolytes through urination in response to decreased levels of blood sugar and the hormone insulin (5).

This loss is typically greatest during the first 1–4 days of transitioning to keto, so muscle cramps related to electrolyte imbalance may be worse during this period (5).

Dehydration

People transitioning to the keto diet often urinate more due to factors like reduced insulin levels and increased sodium excretion. In turn, increased urination can lead to dehydration, another potential cause of leg cramps (1, 5).

Dehydration is one of the most common keto side effects and may thus increase your risk of leg cramps (6, 7, 8).

All the same, evidence is mixed and more studies are needed (9).

Other potential causes

Several other factors may also cause leg cramps.

For example, certain medications, such as diuretics, asthma drugs, and statins, are associated with an increased risk of these pains (10).

Additionally, sedentary habits, old age, strenuous physical activity, and medical conditions like liver and kidney failure are associated with leg cramps (11, 12).

summary

People on the keto diet may experience leg cramps due to dehydration and electrolyte imbalances. Other causes of leg cramps include sedentary habits and certain medications.

Aside from leg cramps, other symptoms associated with the keto diet include headaches, constipation, and fatigue — collectively known as the keto flu.

These symptoms may likewise be caused or worsened by dehydration and electrolyte imbalances, making prevention all the more important.

Tips

The best way to prevent and treat leg cramps on keto is to ensure that you’re eating nutritious foods, supplementing if necessary, and staying properly hydrated. Here are a few tips:

  • Eat potassium-rich foods. Avocados, Swiss chard, spinach, onions, tomatoes, beet greens, and mushrooms are keto-friendly, potassium-rich foods that can help rebalance your electrolyte levels (13).
  • Choose magnesium-rich foods. Pumpkin seeds, Brazil nuts, cashews, kale, arugula, broccoli, and oysters are low in carbs and high in magnesium to aid your electrolytes (14).
  • Consider taking an electrolyte supplement. Taking a magnesium, potassium, or multi-mineral supplement may be a good idea for those transitioning to a keto diet (15).
  • Consume enough salt. Salt your food and consider sipping on salted bone broth to reduce the chances of electrolyte imbalance.
  • Drink plenty of water. Staying properly hydrated may reduce your risk of leg cramps and other keto side effects, such as headaches and constipation. Pale, yellow urine is a sign that you’re properly hydrated (16, 17, 18, 19).
  • Cut back on or avoid alcohol. Alcohol is a diuretic and may worsen dehydration. Some research suggests that alcohol use may be related to leg cramps (20, 21).
  • Engage in gentle exercise. Try walking, stretching, and yoga when first adapting to keto. Avoid intense exercise for the first few days to reduce the chance of leg cramps (22).

If you have persistent or extreme leg cramps, you should visit a health professional to ensure that you’re not experiencing symptoms of a more serious medical condition.

summary

Staying hydrated, consuming plenty of electrolytes, and engaging in gentle physical activity may help reduce your chances of leg cramps on keto.

While many people swear by the keto diet, transitioning to a very low carb, high fat diet can lead to uncomfortable symptoms, including leg cramps.

Nonetheless, making a few simple changes to your diet and lifestyle, such as staying hydrated, eating plenty of electrolyte-rich foods, and engaging in gentle activity, may help treat and prevent keto-associated leg cramps.

If you’re experiencing leg cramps, try out a few of the tips listed above — but remember to visit your healthcare provider if your cramps are persistent or extreme.