Potatoes & vegetables · Glycemic index

Do boiled potatoes spike blood sugar?

Yes — boiled potatoes have a high GI of 73, and a 167 g serving (1 medium potato) has a glycemic load of 22, which is high. Boiled potatoes have a high average GI and a medium potato carries a high glycemic load — but the variety, and whether you eat them hot or cold, change the picture considerably.

Key numbers

Glycemic index: 73; High GI
Glycemic load: 22; High GL
Available carbs: 30 g; 3 g fiber
Serving: 1 medium potato; 167 g · boiled, peeled

GI vs GL for boiled potatoes

The glycemic index (GI) compares how fast the carbohydrate in a food raises blood sugar against pure glucose (100), using a fixed amount of carbohydrate. The glycemic load (GL) adds the other half of the story — how much carbohydrate a normal serving actually contains: GI × available carbs ÷ 100. For boiled potatoes: 73 × 30 g ÷ 100 ≈ 22.

That figure is an average reported in the 2021 international GI tables (“Boiled potato, mean of 29 studies”). Variety makes a big difference: boiled potatoes in the 2021 tables range from 53 (Carisma) to 101 (Desiree, in one older test). Eight tests of potatoes cooked and then eaten cold averaged 49.

Eating a different amount? Work out the glycemic load of your portion.

How to eat boiled potatoes with less of a spike

Cook them ahead and eat them cold: in a Canadian study, red potatoes eaten cold the day after boiling had a GI of 56, versus 89 when eaten hot.
Dress cold potatoes with vinegar and oil — in a Swedish study, cold boiled potatoes tested 67 with vinaigrette against 88 without.
Keep the portion to one small potato and give half the plate to non-starchy vegetables.

Lower-GI swaps

Compare with

See all 67 foods in the glycemic index table

Frequently asked questions

What is the glycemic index of boiled potatoes?

Boiled potatoes have a glycemic index of 73, which is high. That figure is an average reported in the 2021 international GI tables (“Boiled potato, mean of 29 studies”). A 167 g serving (1 medium potato) contains about 30 g of available carbohydrate, giving a glycemic load of 22 (high).

Is boiled potatoes good for prediabetes?

Potatoes don't have to be off the menu, but they work best as a small side rather than the base of the meal. Cold potato salad with a vinaigrette, and lower-GI varieties such as Carisma where available, are gentler options.

Does cooling potatoes lower their glycemic index?

It can. In a Canadian study, red potatoes boiled and eaten cold the next day had a GI of 56 compared with 89 hot, and eight cooked-then-cooled potato tests averaged 49 in the 2021 tables. In a Swedish study, adding vinegar and olive oil to cold potatoes lowered the GI further.

Sources

GI values come from the international GI tables; carbohydrate and fiber per serving are calculated from USDA FoodData Central.

Data last checked September 30, 2026.