Renal Diet 101: Potatoes

RenalTracker Team: September 16, 2019

It either lies beside your carved up turkey on Thanksgiving, arrives at your new neighbors doorstep as a welcoming gift, or just sits there on your dinner table for the family to share.

Whatever the occasion and however it may be prepared, potatoes have long since become a staple ingredient in household dishes. It has, in a way, earned its place in our homes.

But do potatoes still have a place for someone undergoing renal diet?

Spud 101

Potatoes, also known as Solanum tuberosum, are grown for their starchy edible tubers and are considered one of the main food crops all around the world.

Usually, it can be prepared, used, and served in a lot of different ways. The most common ways are:

  • baked (whole baked potatoes)
  • mashed (baking first, then mashing)
  • cooked (as ingredients in a dish)
  • ground (to flour, used for baking and sauce thickener)

These underground-growing crops are also rich in essential vitamins and minerals -- vitamin C, thiamin, and niacin, to name a few.

However, potatoes are also very rich in potassium. And yes, eating potatoes might help people with potassium deficiencies, but too much potassium is a must-avoid for kidney patients.

How Much "K" is In a Tuber?

According to the USDA Database, a medium-sized potato (roughly 213 grams & about 2¼-3 ¼  inches in diameter) contains the following nutrients:

Potatoes (medium-sized)


13 mg


4.37 g


905 mg


121 mg


26 mg


164 kcal


0.19 g


168.80 g


37.25 g

The suggested potassium intake limit for people with kidney disease, per the National Kidney Foundation (NKF), is 2000 mg (or less) daily.

Considering that, it would mean that a single potato can give you almost half of your daily potassium intake in one sitting! That's not accounting the amount of potassium you get from the other food items you eat during the day.

What Experts Say About Potassium

NKF hosted a Facebook Live event with Dr. Laura Byham-Gray from Rutgers University and Dr. Leslie Spry from the Dialysis Center of Lincoln in Lincoln, Nebraska.


They talked about how potassium intake could make or break a person's health.

"Any change in blood potassium," Dr. Spry explains, "can lead to complications such as heart problems, even stoppage on rare occasion, and muscle weakness and cramps.” He further implied that it is imperative that a person should watch his/her potassium intake to avoid complications in your body, especially the heart muscles.

Dr. Byham-Gray also added that while the DASH Diet (Dietary Approaches to Stop Hypertension) is a generally healthy approach for anyone, it is still necessary to learn how to properly portion your food to avoid exceeding your potassium limits.

She further implied that it is important for a person to communicate openly with his/her nephrologist and/or dietitian about controlling potassium intake and monitoring kidney numbers.   

"Hacking" the Potassium in Potatoes

However, undergoing renal diet doesn't mean you should take the joy out of eating, too. You can still enjoy potatoes, albeit in small, dietitian-controlled portions, with this food hack called...


Leaching is a process that helps reduce the potassium content of food. You don’t have to give up high-potassium vegetables, but you'll need more time to prepare them. Here’s how you can do it: 


  1. Peel and place vegetables in cold water (to avoid darkening).
  2. Slice into 1/8 inch thick pieces and briefly rinse in warm water.
  3. Soak in warm water for a minimum of 2 hours. Use ten times the amount of water to the amount of vegetables (e.g., 10 cups of water for 1 cup of vegetables).
  4. Rinse in warm water again for a few seconds
  5. Cook vegetables. Use 5 times the amount of water to the amount of vegetables (e.g., 5 cups of water for 1 cup of vegetables).

Now, although leaching is an effective process, it only reduces potassium and DOES NOT eliminate it entirely. That's why it’s always better and safer to choose low-potassium foods.

Tuber. Tater. Spud.

Anyway you want to call them,  always remember that potatoes can cause quite the trouble for you and your kidneys, so it's best to consult your nephrologist and/or dietitian about potatoes in your renal diet.


Potato - Encyclopaedia Britannica;

Basic Report:  11352, Potatoes, flesh and skin, raw - USDA National Nutrient Database for Standard Reference Legacy Release;

The Meat And Potatoes of Potassium - The National Kidney Foundation;