Glycemic index of potatoes commonly consumed in North America

J Am Diet Assoc. 2005 Apr;105(4):557-62. doi: 10.1016/j.jada.2005.01.003.


Objective: To determine the effect of variety and cooking method on glycemic response and glycemic index of common North American potatoes.

Design: Study 1: subjects consumed 200 g Russet or white potatoes that were either (a) precooked, refrigerated, and reheated (precooked) or (b) cooked and consumed immediately (day-cooked). Incremental area under the curve was determined. Study 2: subjects consumed 50 g carbohydrate portions of white bread or potatoes (six different varieties and two different cooking methods). Glycemic index values were calculated. In both studies meals were consumed after a 10- to 12-hour overnight fast and finger-prick capillary-blood glucose was measured before and at intervals for 2 hours after consumption.

Subjects: The study groups were as follows: Study 1 comprised four men and six women, aged 20 to 44 and Study 2 comprised 11 men and one woman, aged 18 to 50.

Statistical analyses: Repeated measures analysis of variance with Newman-Kuels to protect for multiple comparisons (criterion of significance two-tailed P <.05).

Results: Study 1: Precooked Russet potatoes elicited lower area under the curve than day-cooked (P <.05), while precooking had no effect on boiled white potatoes. Study 2: The glycemic index values of potatoes varied significantly, depending on the variety and cooking method used (P =.003) ranging from intermediate (boiled red potatoes consumed cold: 56) to moderately high (roasted California white potatoes: 72; baked US Russet potatoes: 77) to high (instant mashed potatoes: 88; boiled red potatoes: 89).

Conclusions: The glycemic index of potatoes is influenced by variety and method of cooking and US Russet potatoes have only a moderately high glycemic index. Individuals who wish to minimize dietary glycemic index can be advised to precook potatoes and consume them cold or reheated.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Area Under Curve
  • Blood Glucose / analysis*
  • Blood Glucose / metabolism
  • Bread / classification
  • Cooking / methods*
  • Cross-Over Studies
  • Female
  • Food Handling / methods
  • Glycemic Index*
  • Humans
  • Male
  • Middle Aged
  • North America
  • Solanum tuberosum / classification*
  • Solanum tuberosum / metabolism*
  • Time Factors


  • Blood Glucose