Vegetables
Sweet potato
The beta-carotene and fibre are a clear win, but how you cook a sweet potato can nearly double its effect on blood sugar.
Sweet potato vs potato: what 'the healthier one' actually means
Sweet potato wins beta-carotene by a mile, but potato leads on vitamin C, potassium and vitamin B6. The calories are nearly identical.
Vegetables
Potato
Total potato intake showed no association with type 2 diabetes risk. Only fried potato did, at a hazard ratio of 1.12.
Sweet potato — Leads on
- Fiber
Potato — Leads on
- Protein
- Vitamin C
- Potassium
Nutrition side by side
Per 100 g edible portion. Only rows where both have a figure are shown, and no winner is marked for items like calories or sugars where more is not better.
Basis for these figures
- Potato
- Per 100 g of raw potato, flesh and skin. A medium potato is about 170 g. Frying multiplies the calories three- to fourfold for the same weight.
| Nutrition | Sweet potato | Potato |
|---|---|---|
| Calories | 86 kcal | 77 kcal |
| Protein | 1.6 g | 2.05 g |
| Carbohydrates | 20.1 g | 17.5 g |
| Fiber | 3.0 g | 2.1 g |
| Vitamin C | 2.4 mg | 19.7 mg |
| Potassium | 337 mg | 425 mg |
Bottom line
"Sweet potato is healthier than potato" is widely repeated. The table makes it less simple than that.
Where sweet potato clearly wins is beta-carotene. It carries 8,509 µg per 100 g, a compound potato has essentially none of. The body converts it to vitamin A, which is where the 709 µg comes from; the deeper the orange, the more of it. That row alone is reason enough to eat sweet potato.
But potato wins more rows. Vitamin C runs 19.7 mg against 2.4 mg — eight times — and potassium 425 mg against 337 mg. Vitamin B6 comes in at 0.298 mg, a row the sweet potato table does not have at all. On calories, potato is actually lower: 77 kcal against 86.
The blood-sugar claim needs a correction too. Sweet potato is often introduced as "low glycaemic", but that depends heavily on how it is cooked. Boiled sweet potato is relatively low; baked sweet potato is not, because baking converts starch to sugar. Potato splits the same way by method. It is a cooking question, not a species question.
Beta-carotene is fat-soluble. Eating sweet potato with no fat lowers absorption. A little olive oil, or nuts alongside, works in its favour.
With potatoes, cut away sprouts and any green. Solanine concentrates there. Sweet potato carries no equivalent warning.
The conclusion is to alternate. Sweet potato when you are topping up vitamin A, potato for vitamin C and potassium. Deep-fry either one and the comparison stops meaning anything.