Many people try intermittent fasting as a way to lose weight, but is it suitable for a person with kidney disease? Our nutrition expert advises caution.

Q: I started fasting, but I just read that with any kidney issues, one should not fast. Is this true?

Intermittent fasting is a popular diet trend that people use to lose weight and improve their overall health and well-being.

There are several ways to fast, but the most popular ways include (1, 2):

  • The 16/8 method. This method involves restricting your eating period to 8 hours and fasting for the other 16 hours. Most people skip breakfast.
  • Eat-stop-eat. This option involves fasting for 24 hours once or twice a week.
  • The 5:2 diet. With this method, you’re only allowed to eat 500–600 calories twice a week on nonconsecutive days, but you can eat a normal diet for the other 5 days.

In general, intermittent fasting is safe and suitable for most healthy individuals.

However, if you have kidney disease, it’s important to speak with your healthcare provider before trying intermittent fasting.

Based on the stage and severity of your kidney disease, they can give you personalized advice on whether intermittent fasting is suitable for you.

There’s currently limited research on intermittent fasting and kidney disease. Most relevant studies have involved people with kidney disease who fast during Ramadan, a religious period that involves fasting during daylight hours.

In many of these studies, researchers have found that several people with stage 3 or higher kidney disease experienced poor health outcomes, including kidney damage, worsened kidney function, increased heart disease risk, or acute kidney failure (3, 4, 5, 6).

However, a few other studies have found that fasting during Ramadan with kidney disease was not linked to poor health outcomes. However, one of these studies noted that older adults with kidney disease may still be at risk of adverse health outcomes (7, 8, 9).

Finally, recent studies have shown that fasting slows polycystic kidney disease (PKD) progression in mice models. Still, the evidence of this effect in humans is limited. More research is underway, with the first results from human clinical trials expected soon (10, 11, 12).

In short, it’s unclear whether intermittent fasting is safe for individuals with kidney disease. There may be a risk of adverse health outcomes.

It’s important to speak with your healthcare provider before trying intermittent fasting to see whether, based on the severity of your kidney disease and your overall state of health, it’s safe for you.