Does intermittent fasting help or harm kidney health?

 A one-size-fits-all approach to IF is inappropriate, particularly for those with renal and cardiac vulnerability. Photograph used for representational purposes only
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The trend of intermittent fasting is growing in the community, and it has gained popularity among those trying to improve their general health or control their weight. There has also been interest in the possible benefits of intermittent fasting (IF) in promoting health and combating chronic diseases. But it is important to understand how IF works in order to avoid health issues and ensure optimal outcomes.

The kidney is essential to maintain the body’s equilibrium. Maintaining the body’s balance depends on the kidneys’ ability to filter waste, regulate blood pressure, and control fluid and mineral levels. Any substantial change in eating habits can affect how they operate.

Who can and cannot practice IF

When done correctly, intermittent fasting is generally safe for those with healthy kidneys. It might even be beneficial, by improving blood sugar regulation and reducing inflammation, both of which, over time, can support kidney function. A family history of kidney problems, diabetes, high blood pressure, or pre-existing renal disease, on the other hand, raises concerns. Long-term meal skipping or inadequate hydration can lead to dehydration, which strains the kidneys. Certain forms of fasting that restrict fluid intake, particularly when done for extended periods or in heated environments, could raise the risk of kidney stones or perhaps serious kidney damage.

These days, different salt compositions are increasingly consumed with different kinds of food, which may cause harm rather than benefit a patient with kidney and cardiac problems in particular. Fluid intake in excess can also be a problem with already weak kidneys. While intermittent fasting holds promise as a metabolic intervention, its effects on kidney health depend heavily on individual patient profiles. A one-size-fits-all approach is inappropriate, particularly for those with renal and cardiac vulnerability. It is important to counsel patients on both the potential benefits and risks of IF, offering personalised strategies for safe implementation.

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If in doubt, ask a doctor

Fasting may sometimes create imbalances and may also damage kidney function if done without a doctor’s instructions. Also, deterioration of kidney function can lead to the need for dialysis or a kidney transplant. Dialysis, which occurs multiple times each week, is when a machine is used to filter the body’s waste and fluids. A kidney transplant is where the damaged kidney is replaced with a functioning kidney from a donor. Typically, when patients are on dialysis, it is best not to fast because it may impair their ability to take in their fluids and electrolytes.

Intermittent fasting can be beneficial in certain circumstances, but how it affects kidney function depends on the person’s general health. Before beginning any fasting regimen, anyone with known renal problems or risk factors should speak with a doctor. Simple dietary adjustments can have a significant impact on important organs, and thus, it is always safer to proceed under supervision.

(Dr. Saurabh Khiste is a consultant nephrologist at Manipal Hospital, Baner, Pune. Email: [email protected])