Brown rice has the same amount of carbs as white rice. But, the extra fiber in brown rice slows down the absorption of the carbs.

Quoted: Since brown rice still has the bran intact, it is a much better source of fiber. In fact a cup of brown rice has 3.5 grams of fiber while white rice has less than one gram of fiber.
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Another benefit from eating brown rice is caused by the fiber slowing down the absorption of carbohydrates. This will help tame the blood-sugar roller coaster that can happen from a high sugar-low fiber meal.