
Chronic kidney disease affects more than 1.3 billion Indian. The number has doubled in the past 15 years showing the burden of the disease on the population. Thus, following a “kidney-friendly” diet is crucial for positive long-term outcomes.
Kidneys play a pivotal role in the regulation of electrolytes but when the kidney loses its function, multiple derangements like accumulation of potassium, phosphorus occur in blood. Thus, patients are advised to monitor their dietary intake of protein, sodium, potassium, and phosphorus among other restrictions.
It is the responsibility of dietitians to help patients and their families in careful selection of foods and by preparing foods in such ways that minimize potassium, phosphorus consumption as well as teach them how to flush excess potassium.
Join the FREE webinar, hosted by Dr. Pratim Sengupta and get a free eBook on management of Hypokalemia and Hyperkalemia.
Why is potassium restriction important in renal failure?
High potassium levels can cause severe muscle weakness or an irregular heart rhythm that can be dangerous. When potassium is very high, the heart can stop beating unexpectedly and cause sudden death. High potassium levels can be life threatening without noticeable manifestations or symptoms (and therefore it is known as a silent killer).

The normal serum potassium (level of potassium in blood) is 3.5 mEq/L to 5.1 mEq/L. But in renal disease, when serum potassium is above 5.2mEq/L, dietary potassium needs to be limited. In general, most experts believe that people with impaired kidney function should eat less than 2000mg of potassium per day. But there is no food that does not contain potassium. Even the most nutritious fruits and vegetables contain a certain amount of potassium.
All green leafy vegetables like spinach , fenugreek leaves , parsley , and colocasia leaves contain a huge amount of potassium. Recently, legumes have also been considered as a good source of protein for renal patients. However, despite their benefits, guidelines still recommend a limit to their consumption by these patients because of legumes’ high potassium and phosphorus content.

Other common potassium high foods to avoid are :
- Potatoes
- Banana
- Jaggery
- Nuts and raisins
- Coconut water
How can we reduce potassium in food?
Potassium levels can be diminished in certain vegetables by cooking in a process called leaching. This method can be applied to certain vegetables ( potatoes, sweet potatoes, carrots, beets) and dals .
What is leaching ?
Leaching is a process of soaking raw or frozen vegetables in water for at least 2 hours or overnight before cooking to “pull” some of the potassium , phosphorus out of the food and into the water and then discarding the water . When cooking them, five times more water than vegetables to be used. Before the procedure , vegetables should be chopped in small pieces.
leaching process of vegetables:
Let’s try leaching on potatoes. Despite having high potassium, our favorite potato can be incorporated in the patient’s diet by following process:

- Rinse the raw potatoes thoroughly with water
- Peel and soak it in cold water .
- Chop the potatoes into a few pieces.
- Rinse in warm water for a few seconds.
- Soak for about minimum of two hours or overnight in cold water.
- Cook with five times the amount of water to the amount of potato.
- Drain excess water and cook the potatoes as desired. And, also try to season potatoes with herbs instead of salt.
- Pulses can also be cooked in exactly the same way to reduce potassium content.
But can leaching really solve the problem ?
Several studies show that potato soaking is ineffective to reduce full potassium from fresh raw potato despite following this laborious culinary technique. The whole process takes a lot of time that can be troublesome for the people to do everyday.
From the nutritional aspect, one of the concerns about soaking vegetables is nutrient loss. Water-soluble vitamins like vitamin C, vitamin B, minerals and phytochemicals that have antioxidant properties leach out of vegetables into the cooking water. Renal failure is hypercatabolic disease, which means body’ metabolism becomes doubled leading to the increased need of nutrients but due to leaching out of nutrients , nutritional value of foods are compromised.

Also chopping vegetables into small pieces and then soaking them is even worse because more surface area is exposed to the water and the air, which also oxidizes some nutrients. After soaking for such a long time, if the vegetables go really mushy, if they are bland looking, if the flavor is reduced, patients not only lose the nutrients, but it’s not going to make them want to eat it as well since they already have a reduced appetite. Since leaching eliminates all other essential nutrients and vitamins with potassium, it is recommended to leach only vegetables, which are high in potassium , and other all low-to-medium-potassium vegetables to be cooked in a normal way.

Dietitian could be the best person to guide the patient in choosing the food containing less amount of potassium which do not require leaching of green leafy vegetables after monitoring the patient’s serum potassium level.
I would recommend all readers to use potassium calculator once. Every year many of my kidney patients suffer cardiac arrest just because of potassium imbalance. Only if they knew what caused the potassium level to shoot up. Grab your opportunity today and save yourself and your dear ones today. Kidney disease or diet restrictions does not always cut down to a bland food. Check your safe food options today without delay.
Here is a video to show you how to use world’s first food potassium calculator, please watch it till end and do not forget to like and subscribe our channel.