Unpeeling the Truth: What part of a potato has the most potassium?

According to the Dietary Guidelines for Americans, potassium is a nutrient of concern because most people do not consume enough of it, and potatoes are an excellent source. So, what part of a potato has the most potassium? Contrary to a popular belief, the majority of this essential mineral is actually found in the potato's flesh.

Quick Summary

The majority of a potato's potassium is in its flesh, not the skin, although the skin is also a concentrated source of nutrients. A medium skin-on potato provides a significant amount of the daily recommended potassium. Eating potatoes with the skin on is the best way to maximize intake of this important mineral.

Key Points

• Flesh Contains More Total Potassium: Despite popular belief, the potato's starchy flesh holds the majority of its total potassium content due to its larger mass.

• Skin is Nutrient-Dense: The skin is a concentrated source of potassium and other nutrients like fiber, making it an important part to consume.

• Don't Peel for Max Intake: To maximize potassium, eat the entire potato, including the skin.

• Cooking Method Matters: Baking, roasting, and microwaving whole potatoes are the best methods to retain potassium, as boiling causes leaching.

• Peeling Reduces Potassium: Removing the skin significantly reduces the potato's overall potassium content, removing about 150 mg from a medium potato.

• Potassium is Vital: Potassium is a key electrolyte for heart, nerve, and muscle function and can help regulate blood pressure.

The Myth vs. The Reality: Skin and Flesh Comparison

For years, a common belief has been that all of a potato's nutrients, including potassium, are packed exclusively into its skin. This nutritional myth, while well-intentioned, is inaccurate. The truth is that while the skin is indeed rich in many nutrients, the sheer mass of the starchy flesh means it contains the bulk of the potato's total potassium content. A medium potato with the skin removed can lose approximately 150 mg of its total potassium content, leaving a substantial amount still within the potato itself. To get the maximum benefit, it is important to consume both parts.

Why Potassium is a Vital Mineral

Potassium is an electrolyte that plays a crucial role in maintaining fluid balance, nerve signals, and muscle contractions. An adequate intake of potassium is important for maintaining normal blood pressure, and research suggests that a diet high in potassium and low in sodium may help reduce the risk of hypertension and stroke. With many Americans consuming less than the recommended daily amount, incorporating potassium-rich foods like potatoes into your diet is a smart choice for overall health.

How Cooking Methods Impact Potassium Content

The way you prepare a potato can have a major effect on its final potassium content. The mineral is water-soluble, meaning it can leach out into the cooking water during boiling. For those with kidney conditions who need to limit potassium, this can be a beneficial technique, but for those seeking to maximize their intake, different methods are better.

• To retain potassium: Baking, roasting, or microwaving potatoes whole with the skin on are the most effective methods. These dry-heat methods prevent the mineral from leaching out into water.
• To reduce potassium: For individuals with specific dietary restrictions, boiling peeled and chopped potatoes can remove a significant percentage of the potassium. Discarding the water and boiling again (double-cooking) can reduce it even further.

Comparing Potassium in Skin-On vs. Peeled Potatoes

The following table illustrates the nutritional difference, emphasizing that while the skin adds a boost, the flesh is the primary source of potassium.

Nutritional Component	Medium Potato (approx. 5.3 oz) with Skin	Medium Potato (approx. 5.3 oz) Peeled
Potassium	620 mg	~470 mg (approximate)
Dietary Fiber	2 grams	1 gram
Vitamin C	27 mg	~22.5 mg (approximate)

Practical Tips for Enjoying Potassium-Rich Potatoes

To make the most of this versatile vegetable, consider these simple preparation tips:

• Enjoy baked or roasted potatoes with the skin on: Scrub them clean and bake them whole. This ensures you get all the nutrients without any losses.
• Create healthy mashed potatoes: For mashed potatoes, boil them whole and unpeeled to minimize leaching. Mash with a splash of low-sodium milk or Greek yogurt instead of high-sodium butter or salt.
• Make nutritious potato salads: If boiling is your preferred method, save the water. Use it for soups or stocks to reclaim the leached potassium and other vitamins.

Beyond Potatoes: Other Potassium-Rich Foods

While potatoes are a potassium superstar, a balanced diet includes a variety of sources to meet daily needs. Some excellent alternatives include bananas, beans, lentils, sweet potatoes, and spinach. Incorporating a mix of these foods ensures you're getting a wide range of essential vitamins and minerals.

Conclusion

Ultimately, the part of a potato with the most potassium is the flesh, though the skin is a valuable and concentrated source of this mineral and should not be discarded. The best strategy for maximizing potassium intake from potatoes is to eat them whole, with the skin on. Healthy cooking methods like baking or roasting can help preserve the mineral content, making a baked potato with the skin a powerhouse of nutrition and a far superior source of potassium than a peeled and boiled one. By understanding the nutritional breakdown, you can make informed choices to support your overall dietary health.

For more information on the DASH eating plan, which emphasizes potassium-rich foods, visit the National Heart, Lung, and and Blood Institute: https://www.nhlbi.nih.gov/health/dash.

References

• Potatoes USA. (n.d.). Potato Nutrition in Skin vs Flesh.
• Healthline. (2025, June 19). 14 Healthy Foods That Are High in Potassium.
• Cleveland Clinic. (2024, March 13). Beyond Bananas: 16 Potassium-Rich Foods.

Frequently Asked Questions

Is the potato skin the most potassium-rich part?

No, while potato skin is rich in nutrients, the majority of the potassium is found in the starchy flesh. The misconception arises because the skin is a very concentrated source, but the sheer volume of the flesh means it contains more total potassium.

How much potassium is lost when you peel a potato?

Peeling a medium (5.3 ounce) potato can remove approximately 150 mg of potassium, along with about half of its dietary fiber.

What's the best way to cook potatoes to maximize their potassium?

To retain the most potassium, you should cook potatoes with the skin on using methods that don't involve boiling water. Baking, roasting, or microwaving are ideal.

Can boiling potatoes with the skin on prevent potassium loss?

Boiling potatoes with the skin on is a much better way to retain potassium than boiling them peeled. The skin acts as a protective barrier that minimizes leaching into the water.

What if I need a low-potassium diet? Can I still eat potatoes?

Yes, if you need a low-potassium diet, you can prepare potatoes to reduce the mineral content. Boiling peeled, chopped potatoes can remove a significant amount of potassium. Discarding the water and boiling again (double-cooking) can reduce it even further.

Are sweet potatoes a better source of potassium than white potatoes?

Both white potatoes and sweet potatoes are excellent sources of potassium. A medium white potato often has more potassium than a medium sweet potato, but both are nutritious choices to include in your diet.

Does frying a potato affect its potassium content?

Yes, frying can reduce the potassium content, especially if the potatoes are peeled and boiled first. However, frying also dramatically increases the calorie and fat content, making it a less healthy option than baking or roasting.