Bananas are the popular shorthand for potassium, but they do not top every ranking. A raw banana provides about 358 mg potassium per 100 g; raw beet greens are around 760 mg and spinach about 560 mg for the same weight. A useful comparison therefore needs both numbers and realistic serving sizes.
Potassium-rich vegetables per 100 g
Ranking foods per 100 grams is useful, but it does not always describe what ends up on the plate. A vegetable eaten in a large serving can provide more total potassium than another with a slightly higher value per 100 grams that is used only as a small side. Portion size therefore changes the practical ranking. A whole potato, a bowl of cooked greens, and a scoop of squash do not weigh the same, so database order and contribution to a real meal can be different.
| Raw food | Approx. potassium/100 g | Compared with banana |
|---|---|---|
| Beet greens | ~760 mg | ~2.1× |
| Spinach | ~560 mg | ~1.6× |
| Brussels sprouts | ~390 mg | Slightly more |
| Swiss chard | ~380 mg | Very similar |
| Broccoli | ~315 mg | Somewhat less |
| Banana, reference | ~358 mg | — |
Values are rounded and shift with cultivar, maturity, and preparation. The point is to show scale, not to turn a difference of a few dozen milligrams into a meaningful nutritional victory.
Serving size can change the practical ranking
Potassium is spread across the diet rather than concentrated only in vegetables. Beans, dairy foods, fruit, nuts, and several other groups can contribute meaningful amounts. That makes it unnecessary to treat one vegetable as a mandatory potassium source. For people without a medical restriction, rotating different vegetables through the week also brings fiber, carotenoids, folate, and other nutrients that a potassium-only ranking cannot show. Variety usually gives a more useful nutritional picture than chasing a single winner.
One hundred grams of raw spinach is a very large bowl. Eating 150–200 g of broccoli as a side dish is much more ordinary. At the values above, 200 g broccoli would provide about 630 mg potassium, compared with roughly 360 mg in a small 100 g banana.
That is why “which food has more per 100 g?” and “which food contributes more on my plate?” are different questions.
Cooking can concentrate potassium or move it into water
Potassium is a mineral, so heat does not destroy it. Losing water during cooking can make the food look more concentrated per 100 g. However, potassium is water-soluble, and some can move into cooking liquid. Boiling in plenty of water and discarding that water can therefore lower the amount eaten.
A USDA reference for cooked beet greens reaches about 903 mg per 100 g; a half-cup serving supplies roughly 650 mg. Part of that high concentration reflects how dramatically leafy greens shrink during cooking.
You do not need one potassium “champion”
When vegetables are boiled and the water is discarded, some potassium can move into the cooking liquid. The amount depends on cutting, cooking time, and water volume, so a database value for a cooked food may not exactly match your preparation. Roasting, steaming, or using the cooking liquid in soup retains more of what would otherwise be leached away. That difference becomes especially relevant for people who have been specifically advised to control potassium intake for a medical reason.
Potatoes, beans, leafy greens, tomatoes, dairy foods, fish, and many fruits all contribute. A varied diet can add up to a high potassium intake without relying on one famous food.
One important exception
If kidney disease or another clinical situation requires potassium restriction, a list of high-potassium foods should not be treated as advice to eat more of them. Lab results, medication, portion size, and preparation method can all matter in that setting. For most other people, the practical approach is simpler: eat a varied mix of vegetables and include generous servings of naturally potassium-rich choices regularly. That supports intake without turning the mineral into a reason to rely on supplements or one particular food.
For most healthy people, potassium-rich foods are encouraged. People with certain kidney diseases or medications may need individualized potassium limits and should follow clinical guidance.
Several vegetables can beat a banana on potassium, but the useful comparison combines concentration, serving size, and cooking method.
Sources
- USDA FoodData Central — Potassium values for vegetables.
- NIH Office of Dietary Supplements — Potassium Fact Sheet for Health Professionals — Potassium functions, food sources, and clinical considerations.