For a food to be able to increase your blood sugar levels, it needs to have enough carbohydrates per serving. Carbohydrates include both starches and sugars, which are mainly found in grain- or flour-based foods, starchy vegetables, desserts, candies and sweetened beverages. The carbohydrates in fruits come from their natural sugar, and fruits can cause your blood sugar levels to increase.
Fresh Fruits
Fresh fruits naturally contain carbohydrates from a mixture of sugars, such as fructose, glucose and sucrose. For example, a small apple, orange or pear provides approximately 15 g of carbohydrates, which is the equivalent of carbohydrates found in a slice of bread, while larger fruits can provide up to 30 g to 50 g of carbohydrates. Berries have a slightly lower carbohydrate content, with about 7 g to 10 g of carbohydrates per cup, whether you choose strawberries, raspberries or blueberries. Eating fresh fruits can raise your blood sugar levels, depending on how much you have at a time.
Fruit Juices
Fruit juices can increase your blood sugar levels even faster and higher compared to fresh fruits because the carbohydrates they contain are quickly absorbed. Almost no digestion is required with fruit juices because they are already liquid and free of fiber. A drink box of unsweetened juice, which is the equivalent of 8.5 oz., contains around 30 g of carbohydrates, or the equivalent of two slices of bread. If you pour yourself a 16 oz. glass of juice or drink juice from a large bottle, you could easily be getting more than 60 g of carbohydrates, or the equivalent of four slices of bread, which could cause your blood sugar levels to peak within a short period.
Dried Fruits
Dried fruits contain more carbohydrate per serving compared to fresh fruits because the dehydration process concentrates the natural sugars of the fruit. Some dried fruits may also contain added sugar. For example, a 1/4-cup serving of raisins and a 1/3-cup serving of dried cranberries each contain just over 30 g of carbohydrates, or about the same amount of carbohydrates found in two slices of white or whole wheat bread. Limit your servings of dried fruits and choose dried fruits that do not contain added sugar to prevent a large increase in your blood sugar levels.
Canned Fruits
The carbohydrate content of canned fruits can vary significantly depending on the amount of added sugar they contain. A serving of 1 cup of fruit cocktail packed in heavy syrup has more than 45 g of carbohydrates, or the equivalent of three slices of bread, whereas the same canned fruit cocktail packed in light syrup has 35 g of carbohydrates. Fruit cocktail packed in water contains less than half the amount of carbohydrates found in canned fruits packed in heavy syrup, or about 20 g per cup.
