Potatoes & vegetables ¡ Glycemic index
Do mashed potatoes spike blood sugar?
Yes â mashed potatoes have a high GI of 79, and a 210 g serving (1 cup) has a glycemic load of 27, which is high. Mashed potatoes average a high GI â instant mash tested higher still â so a cup carries a high glycemic load.
Key numbers
- Glycemic index
- 79
- High GI
- Glycemic load
- 27
- High GL
- Available carbs
- 34 g
- 3.2 g fiber
- Serving
- 1 cup
- 210 g ¡ home-made with milk
GI vs GL for mashed 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 â how much carbohydrate a normal serving actually contains: GI Ă available carbs á 100. For mashed potatoes: 79 Ă 34 g á 100 â 27.
That figure is an average reported in the 2021 international GI tables (âMashed potato, mean of five studiesâ). Instant mashed potato averaged even higher, at 84 across five studies.
Eating a different amount? Work out the glycemic load of your portion.
How to eat mashed potatoes with less of a spike
- Make your own rather than using instant flakes, which averaged 84.
- Mash half potatoes and half cauliflower or other non-starchy vegetables.
- Serve half a cup next to protein and green vegetables.
Lower-GI swaps
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Frequently asked questions
What is the glycemic index of mashed potatoes?
Mashed potatoes have a glycemic index of 79, which is high. That figure is an average reported in the 2021 international GI tables (âMashed potato, mean of five studiesâ). A 210 g serving (1 cup) contains about 34 g of available carbohydrate, giving a glycemic load of 27 (high).
Is mashed potatoes good for prediabetes?
Mashed potatoes are best as a small side. Stretching them with mashed cauliflower or other non-starchy vegetables lowers the carbohydrate in each spoonful.
Is instant mashed potato worse than homemade?
Slightly, on GI: instant mashed potato averaged 84 across five studies in the 2021 tables, against 79 for regular mashed potato. Both are high GI.
Sources
GI values come from the international GI tables; carbohydrate and fiber per serving are calculated from USDA FoodData Central.
- Atkinson FS, Brand-Miller JC, Foster-Powell K, Buyken AE, Goletzke J. International tables of glycemic index and glycemic load values 2021: a systematic review. Am J Clin Nutr. 2021;114(5):1625â1632, Supplemental Table 1
- USDA FoodData Central, FDC ID 170493: Potatoes, mashed, home-prepared, whole milk added
Data last checked .