If you are diabetic or on a low-carb diet, you probably already know that both rice and potatoes are pretty high in carbs. However, it can be helpful to know just how many carbs each of these foods contain so you can determine how to fit them into your diet.
A 100-gram serving of medium-grain white rice, or about 1/2 cup, contains 28.6 grams of carbohydrates, while the same amount of brown rice provides 23.5 grams. If you choose a russet potato with the skin, a 100-gram serving, or slightly more than half of a medium potato, has 21.4 grams, while the same amount of red-skin potato provides 19.6 grams.
To get the net carbs in rice or potatoes, you would subtract the fiber content from the total carbs, since it isn't digested so it doesn't increase your blood sugar levels. Fiber also helps lower your blood sugar and cholesterol, as well as your risk for heart disease and constipation. Each 100-gram serving of russet potato has 2.3 grams of fiber, or 9 percent of the daily value. Both red-skin potatoes and brown rice contain 1.8 grams of fiber per 100-gram serving, but white rice only has 0.3 gram per serving.
Some foods that are relatively high in carbohydrates don't have large effects on blood sugar levels due to the type of carbs they contain and the other components in the food. The glycemic index measures how much foods typically affect blood sugar levels, with those ranked 55 or below being considered low-GI foods and those 70 and above considered high-GI foods. Potatoes are high on the glycemic index, with a score of 111 for a baked russet potato or 82 for a boiled white potato, as is white rice with a score of 89. However, brown rice has a low GI score of 50, making it the best choice in terms of blood glucose control.
Both rice and potatoes provide essential vitamins and minerals and are fine to eat in moderation. You just need to take their carbohydrates into account when planning your meals and eat them with lower-carb foods to minimize your overall carbohydrate intake if you are watching your carbs. Pair them with green leafy vegetables and a lean protein source like fish or skinless chicken breasts to round out your meal without greatly increasing your carbs.