Potato

Food · Vegetable · Food, Typed Supps

More potassium than a banana, and the cooking method decides everything else.

Stage by stage

Skin on (The tuber): Most of the fibre and much of the potassium sit in and just beneath the skin.
Preparation decides (The pan): 110 calories baked, 226 as chips — the difference is entirely what was added.
Resistant starch (Colon): Cooling converts some starch into a form that ferments rather than being absorbed.
Potassium (Circulation): 670 mg per 100 g, around 80% more than a banana by weight.

What the evidence supports

Supplying potassium and vitamin C — strong evidence. 670 mg potassium per 100 g, roughly 1.8-fold banana by weight, plus 23 mg vitamin C. Because potatoes are eaten in volume they are a meaningful population source of both.
Evidence that it causes Causing weight gain or metabolic harm as a vegetable — insufficient evidence. The cohort associations track preparation, not the tuber: 110 kcal baked against roughly 226 as chips, from the same vegetable.

Timing

Cook, cool, then eat. Refrigerating a cooked potato overnight builds resistant starch, and reheating keeps a good part of it.

Time to effect

Hours: Resistant starch forms as a cooked potato cools.
Per 100 g: 670 mg potassium and 23 mg vitamin C, baked.

Allergens

None of the fourteen major allergens. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Low-FODMAP, Gluten-free.

Satiety

323 on the satiety index, where white bread is 100 — very high. Measured by Holt et al. (1995).

Environmental footprint

0.5 kg CO2e and 59 litres of freshwater per kg, matched to "Potatoes" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £1.4 per kg, as a band midpoint rather than a price.

Key nutrients

Nutrition per 100g

Calories: 110
Protein: 3.8g
Carbohydrate: 20.8g
of which sugars: 0.7g
Fat: 0.2g
Fibre: 3.3g
Sodium: 7mg

Food vs. supplement

Potatoes are the vegetable Australians eat most, which means their preparation matters more at population level than almost any other food choice. The gap between baked and fried is a twofold difference in energy on identical produce.

Kitchen tip

Cook it the day before and eat it cold or reheated. The starch that reforms on cooling behaves more like fibre than like starch.

Common myth

“Potatoes are fattening — I’ve cut them out.” In reality: A baked potato is 110 calories and 0.2 g of fat per 100 g, with more potassium than a banana and a useful amount of vitamin C. Hot chips are 226 calories and around 10 g of fat — the same vegetable, plus oil. The cohort associations between potatoes and poor outcomes track the frying, not the tuber. Cut the chips, not the potato.

Recipes that use it

In the glossary

Absorption