Rice and potatoes are rich in starches, and both of these foods can cause a marked increase in your blood sugar levels. But you don’t have to eliminate them from your diet to maintain stable blood sugar levels, according to the Glycemic Index Foundation. Instead, combine these starchy foods with those that have a low glycemic index value to minimize their negative effects.
Glycemic Index Values
The glycemic index ranks the effects of a food that contains carbohydrates on your blood glucose levels. Foods that elevate blood sugar quickly and significantly rank higher on a scale of 1 to 100 than foods that have a low to moderate effect. Foods that score higher than a 55 are considered high-glycemic index; anything less than a 55 is considered low-glycemic index according to the Glycemic Index Foundation. The type of rice and the cooking method may cause some variation in index values. Boiled white rice has a value ranging from the 70s to high 80s. Boiled brown rice has a value ranging from the high 60s to the high 80s. A baked potato has a value ranging from 78 to 111, while a boiled potato has a value of 89.
The starches in rice and potatoes are complex carbohydrates, which your body breaks down into glucose -- a form of sugar that is the primary source of fuel for your muscles and vital organs. Your body breaks down the starches in rice and potatoes very quickly, resulting in a more rapid increase in the level of glucose in your bloodstream. The longer you cook a starchy food like potatoes and rice, the more gelatinized the starch becomes, which raises its glycemic index value, according to the UMass Memorial Medical Center. The type of starch in a food can also affect its glycemic index value. Basmati rice is high in amylose, which has a less significant effect on blood sugar than amylopectin, another form of starch found in rice. The value of basmati rice is only 57, which makes it a moderate-glycemic index food.
The glycemic load combines the glycemic index value of a food with the amount of carbohydrates in that food to determine that food’s glycemic potency. A 150-g, or 1.5-cup, serving of boiled white rice has a glycemic index value of 83, 36 g of carbohydrate per serving and a glycemic load of 30. A 150-g serving of boiled red potatoes has a glycemic index value of 89, 21 g of carbohydrate per serving and a glycemic load of 19. Because rice and potatoes are high in carbohydrates that have a significant effect on blood sugar, they have a high glycemic load, as well as a high glycemic index. By comparison, a 120-g apple has a glycemic index value of 34, 16 g of carbohydrate per serving and a glycemic load of 5. The apple has few carbohydrates relative to its volume, and these carbohydrates have a low effect on blood glucose levels. That results in a low glycemic load.
If you’re using the glycemic index value of foods to fine-tune the carbohydrate content in your meals, serve moderate portions of rice or potatoes with foods that have a low glycemic index value. The glycemic effects of a low-glycemic index food can balance out the effects of a food with a higher index number. Foods that contain mostly protein and fat, such as meat, poultry and eggs, have no notable effect on blood sugar. Vegetables such as broccoli or lettuce have such low amounts of digestible carbohydrate that their glycemic index level can’t be evaluated. Foods that are high in soluble fiber, a viscous form of fiber that delays your body’s conversion of carbohydrates into glucose, also have a low glycemic index number. Foods high in soluble fiber include legumes and oats. The Glycemic Index Foundation recommends that you eat at least one low-glycemic index food per meal to maintain stable blood sugar levels.