Sources of high GI carbohydrates are those that are high in refined sugar and refined starch, "starchy carbs". Examples of high GI carbohydrates are most cereals (cereals high in bran have a lower GI), white bread, potatoes, rice, popcorn, and carrots. Now, be reasonable, although carrots are high on the GI, a person would have to consume a large amount of carrots, daily, in order to get the full effect as you would from a normal serving of something like white bread. Sources of low GI carbohydrates are those that are high in fiber. Examples include virtually all vegetables (excluding carrots) and fruit. While fruit is high in sugar, fructose, it is low in glucose, which is why it is a low GI carbohydrate. Another reason why vegetables and fruits are low on the GI is because they both contain relatively larger amounts of fiber. Fiber cannot be digested and absorbed for energy by the small intestine. However, fiber can be broken down in the large intestine by bacterial flora. This process results in fermentation in the colon to produce carbon dioxide, alcohol, and/or an organic acid.