Is there anything unhealthy about potatoes? Unpacking the nutritional facts

October 7, 2025 •

5 min read

According to a 2017 study in The American Journal of Clinical Nutrition, people who ate fried potatoes twice a week had an increased risk of mortality. This finding highlights a central point: while the potato itself is a nutritious whole food, the answer to the question, "Is there anything unhealthy about potatoes?", lies mostly in how they are prepared.

Quick Summary

The health impact of potatoes depends largely on cooking methods, toppings, and portion sizes. While fried and processed versions carry risks like high glycemic load and unhealthy fats, baked or boiled potatoes with healthy accompaniments offer key nutrients and satiety benefits.

Key Points

Preparation is Key: The health risks of potatoes are primarily tied to cooking methods like deep-frying and high-calorie toppings, not the vegetable itself.
High Glycemic Index: Some potato varieties can cause rapid blood sugar spikes, a concern for people with diabetes. This can be managed by preparation and food pairing.
Weight Gain Risk: Studies show a correlation between long-term weight gain and high consumption of fried and heavily processed potatoes, though moderation is key.
Toxic Glycoalkaloids: Green or sprouted potatoes can contain solanine, a toxic compound. They must be properly stored, and affected parts should be discarded before cooking.
Nutrient-Rich When Whole: Whole potatoes with the skin on are an excellent source of potassium, vitamin C, fiber, and other nutrients.
Resistant Starch Benefits: Cooking potatoes and then cooling them increases resistant starch, which can improve gut health and lower the glycemic response.
Balance Your Plate: For best results, treat potatoes as a starch and balance your meal with lean proteins, healthy fats, and a variety of other vegetables.

The Core Nutritional Value of a Potato

At its heart, the humble potato is a powerhouse of nutrients. A medium, skin-on potato is naturally low in fat, cholesterol-free, and an excellent source of vitamins and minerals. It is particularly known for its high potassium content, which is essential for maintaining healthy blood pressure and nerve function, and it contains even more potassium than a banana. Potatoes also provide a significant amount of vitamin C, a potent antioxidant that supports immune health and aids in collagen production.

Beyond the vitamins, potatoes are rich in dietary fiber, especially when the skin is consumed. This fiber aids in digestion, promotes a feeling of fullness, and can help with weight management. The carbohydrates present are a source of energy for the body, though the type of carbohydrate and how it's released into the bloodstream varies. Potatoes also contain other beneficial plant compounds, including powerful antioxidants like quercetin, which offer anti-inflammatory effects.

Essential Nutrients Found in a Potato (medium, with skin)

Potassium: Essential for blood pressure and fluid balance. A medium potato has more than a banana.
Vitamin C: An excellent source of this antioxidant, supporting immune function.
Vitamin B6: Important for energy metabolism and brain health.
Dietary Fiber: The skin is particularly rich in fiber, which aids digestion and satiety.
Protein: Provides a small but high-quality source of plant-based protein.
Iron: A good source of this mineral, involved in oxygen transport.

When Potatoes Become Unhealthy: The Role of Preparation

The unhealthiness of potatoes often stems from how we prepare them. The cooking method can drastically alter a potato's nutritional profile, introducing excess fat, sodium, and calories. Deep-frying, for example, is the most common culprit. Frying potatoes in oil, especially at high temperatures, increases their fat and calorie content significantly and can lead to the formation of potentially harmful compounds like acrylamide.

Furthermore, the toppings we add can transform a healthy food into an unhealthy one. While a plain baked potato is a nutritious option, loading it with butter, cheese, sour cream, and bacon adds saturated fat and calories that contribute to poor health outcomes, including weight gain. The combination of fried potatoes (like french fries) with high-fat, high-sodium fast-food meals is a particularly detrimental dietary pattern.

Glycemic Index and Blood Sugar Effects

Another significant concern for some individuals, particularly those with diabetes or at risk of developing it, is the glycemic index (GI) of potatoes. The GI is a measure of how quickly a food raises blood sugar levels. Many common potato varieties, like Russets, have a high GI, meaning their starch is rapidly digested into glucose. This can cause a sharp spike in blood sugar, followed by a potential crash, and studies have shown a link between high potato intake and an increased risk of type 2 diabetes.

Managing the Glycemic Response

However, the GI of potatoes is not a fixed number and can be influenced by several factors:

Cooking Method: Boiling and then cooling potatoes increases their content of "resistant starch," a type of fiber that slows digestion and lowers the GI. A potato salad, therefore, may have a lower glycemic load than a hot baked potato.
Variety: Some varieties, like waxy or new potatoes, have a lower GI than starchy ones like Russets. Sweet potatoes also generally have a lower GI.
Food Pairings: Eating potatoes with foods high in protein, healthy fats, or fiber can slow down the absorption of glucose and blunt the blood sugar spike.

Potential Dangers: Toxic Glycoalkaloids

One of the most serious but rare health concerns related to potatoes is the presence of toxic compounds called glycoalkaloids, primarily solanine. Potatoes naturally produce these compounds as a defense mechanism against pests, but improper handling and storage can cause them to accumulate to dangerous levels. High levels of solanine are indicated by a green tint on the potato's skin, a bitter taste, or the presence of sprouts. Symptoms of solanine poisoning can include digestive issues, headaches, and neurological problems, though severe cases are extremely rare.

To avoid this risk:

Store potatoes in a cool, dark, and dry place to prevent them from turning green.
Always cut away any green parts and sprouts, as these are where solanine concentrates.
Discard any potatoes that are very green, shrunken, or have a bitter taste.
Important note: Cooking, including boiling or baking, does not destroy solanine, so trimming or discarding affected potatoes is the only safe option.

Healthy vs. Unhealthy Potato Preparations


Aspect	Healthy Preparation (Baked, Boiled, Steamed)	Unhealthy Preparation (Fried, Chips, Loaded)
Cooking Method	Dry heat (baking) or wet heat (boiling, steaming) preserves nutrients and avoids added fats.	Submerged in hot oil (frying) or processed into chips adds significant fat and calories.
Fat Content	Naturally low in fat, often less than 1 gram per serving.	Can absorb a high volume of oil, dramatically increasing fat and calorie count.
Nutrient Retention	Baking with the skin on retains most vitamins and minerals. Boiling with the skin minimizes nutrient loss to water.	High heat and removal of the skin can destroy or leach out water-soluble nutrients.
Sodium Content	Naturally sodium-free, allowing for controlled seasoning.	Heavily salted, processed, and fast-food versions can contain dangerously high levels of sodium.
Glycemic Load	Can vary but is controllable, especially by cooling after cooking or choosing certain varieties.	Typically higher, contributing to more pronounced blood sugar spikes.

Navigating Potatoes in a Healthy Diet

Instead of completely eliminating potatoes, a healthy diet incorporates them thoughtfully. Think of a potato as a source of energy (carbohydrates) for your meal, similar to rice or pasta, and pair it with other non-starchy vegetables, lean protein, and healthy fats. This approach ensures a balanced plate and helps mitigate potential blood sugar spikes.

Choose mindful cooking methods: Focus on baking, boiling, or steaming. Roasting with a minimal amount of healthy oil, like olive oil, is also a great option.
Embrace the skin: The skin is a nutritional goldmine of fiber and minerals, so always leave it on when appropriate.
Be creative with toppings: Replace high-fat toppings with healthier alternatives. Try Greek yogurt or salsa instead of sour cream, or add herbs and spices for flavor instead of butter.
Opt for variety: Mix up your potato choices. Sweet potatoes offer a lower GI and different antioxidants, while purple potatoes boast unique phytonutrients.
Practice portion control: A moderate portion of potatoes as part of a larger, well-balanced meal is key to avoiding overconsumption of calories and carbs.

For more information on balancing potatoes in your diet, you can refer to authoritative sources like the Harvard T.H. Chan School of Public Health's guide to potatoes.

Conclusion: Context is Everything

In conclusion, the question of whether potatoes are unhealthy is not straightforward and lacks a simple yes-or-no answer. A potato, in its whole, unprocessed form, is a nutrient-dense food that can provide significant health benefits. The primary risks associated with potatoes are not inherent to the vegetable itself but are a direct result of how they are prepared and what they are served with. By prioritizing healthy cooking methods, being mindful of toppings and portion sizes, and taking simple precautions against toxic glycoalkaloids, potatoes can be a safe and valuable part of a balanced diet. It's the preparation, not the potato, that truly determines its impact on your health.

Frequently Asked Questions

You should not eat potatoes with a heavy green tint or a bitter taste. The green color indicates the presence of solanine, a toxic compound. While small green spots can be cut away, heavily green potatoes should be thrown out as cooking will not eliminate the toxin.

To lower the glycemic impact, choose waxy or new potato varieties, and try boiling them before cooling completely, as this increases resistant starch. Pairing potatoes with protein, healthy fats, or fiber also helps slow digestion and prevent blood sugar spikes.

Both sweet and white potatoes are nutritious, but sweet potatoes often have a slightly lower glycemic index and a higher concentration of certain nutrients like vitamin A. However, both are part of a healthy diet when prepared properly.

Boiling can cause some water-soluble nutrients, like vitamin C, to leach into the water. To minimize this, cook potatoes with the skin on. Steaming and baking are also excellent methods for preserving nutrients.

Yes, eating the skin is important, as it contains a significant amount of the potato's fiber, potassium, and other nutrients. Thoroughly wash the skin and cook it with the potato for maximum health benefits.

Acrylamide is a chemical compound that can form in starchy foods, including potatoes, when cooked at high temperatures like frying or roasting. To reduce exposure, avoid heavily browning or burning potatoes during cooking, especially with fried or processed products.

The potato itself is not inherently fattening. Weight gain is more likely from high-calorie, high-fat preparations like french fries or toppings like butter and cheese. Baked or boiled potatoes can be quite filling and support weight management when part of a balanced diet.