Cool Your Spuds

The glycemic index of potatoes varies, so choose the type with the lowest glycemic index to help stabilize blood sugar levels.

A potato is a potato is a potato, right? Wrong. Researchers at the University of Toronto tested how the type of potato and its method of cooking affects its glycemic index (GI), a rating based on how quickly a food is converted to sugar in the body. The lower the GI on a scale of 1 to 100, the longer it takes for the food to be broken down, digested and absorbed. Understandably, foods with lower GI ratings, such as broccoli (15) and grapefruit (25), are better for maintaining stable blood sugar and insulin levels. In their study, the researchers found that the GI of potatoes varies significantly based on the variety and method of cooking. Furthermore, they determined that refrigeration lowers the GI of boiled potatoes, as when they’re eaten cold or even reheated in casseroles.

 

GI Rating	Variety	Method of Cooking
56	Red potatoes	Boiled, consumed cold (e.g., potato salad)
72	White California potatoes	Roasted
77	Russet potatoes	Roasted
88	Instant mashed potatoes
89	Red potatoes	Boiled, consumed immediately