The banana has become almost synonymous with potassium. The association is not wrong, but it gives bananas more nutritional celebrity than their actual ranking supports.
Potatoes, beans, greens, fish, yogurt, avocado and dried fruit can all contribute substantial amounts. Potassium is spread widely across foods, so the overall pattern matters more than one famous example.
Serving size changes the ranking
| Food | Serving | Potassium, approx. |
|---|---|---|
| Baked potato with skin | 1 medium | ~900 mg |
| Cooked spinach | 1 cup | ~840 mg |
| Cooked salmon | 5 oz | ~750–900 mg |
| Cooked lentils | 1 cup | ~730 mg |
| Avocado | ~3.5 oz | ~485 mg |
| Banana | 1 medium | ~420 mg |
| Plain yogurt | 7 oz | ~300–500 mg |
A medium potato can provide roughly twice as much potassium as a medium banana. That does not make the banana a bad source; it simply means its reputation is not the same thing as first place.
A serving-based comparison also avoids another trap: some foods look extremely rich per 100 grams but are eaten in small amounts, while moderate foods may reach the plate in much larger portions. Actual intake depends on the amount eaten.
Potatoes stand out partly because the serving is large
Per 100 grams, a potato does not look extraordinary. But a medium potato can weigh 6–7 ounces and approach 900 mg of potassium. Portion size changes the practical result.
Boiling and discarding the water can reduce potassium, which matters for people who have been medically advised to limit it, while baking with the skin retains more.
Preparation therefore matters as well as food choice. For someone simply building a varied diet, a baked potato is a practical source. For someone following a clinical potassium restriction, cooking methods should match the individualized guidance they have received.
Beans add potassium together with fiber and protein
A cup of cooked lentils provides roughly 700–750 mg. Beans and soy foods can also supply several hundred milligrams per serving. Their practical advantage is that the potassium comes with fiber and plant protein.
Beans are also usually eaten as part of a substantial meal rather than a token garnish. That combination of serving size and mineral density helps explain their large contribution even when they are not the single highest food per 100 grams.
Dried fruit is concentrated because water has been removed
Dried apricots, prunes and raisins can look extremely high in potassium per 100 grams, but a realistic serving is much smaller. Water loss concentrates potassium, sugar and calories at the same time.
A small portion can therefore be useful, but it is not equivalent to eating the same weight of fresh fruit. The concentration applies to energy and natural sugars as well as minerals.
Fish and dairy contribute too
A 5-ounce serving of salmon can provide roughly 750–900 mg depending on species and preparation. A serving of yogurt can add a few hundred milligrams. Potassium does not have to come only from fruits and vegetables.
That diversity makes it easy to distribute potassium across meals: yogurt at breakfast, beans at lunch, potatoes or vegetables later, and fish on another day all contribute without relying on one food.
More potassium is not automatically better for everyone
For healthy people, a potassium-rich diet usually reflects a varied intake of minimally processed foods. People with kidney disease or those taking certain medications, however, may need individualized potassium limits.
Salt substitutes containing potassium chloride deserve particular care because they can deliver large amounts in a small volume. They are not a casual way to “boost potassium” for someone with a medical condition or medication that affects potassium handling.
The useful rule
Bananas provide potassium, but they do not own the nutrient. A diet that regularly includes potatoes, beans, vegetables, fruit, fish and dairy can contribute far more potassium than relying on one famous food.
Sources
- USDA FoodData Central — Food nutrient composition.
- NIH Office of Dietary Supplements — Potassium — Food sources and cautions for kidney disease and salt substitutes.