Juicy, sweet and full of flavor, fruit contains natural sugars, making it a healthy way to satisfy a sweet tooth. Fruits all contain fructose and glucose, in addition to essential minerals and vitamins, as well as dietary fiber. Your body uses both fructose and glucose as an energy source, providing fuel for your daily activities and general body function. The U.S. Department of Agriculture recommends 1 1/2 to 2 cups of fruit per day.
Fructose is a simple sugar found in all ripe fruits. it can also be processed into a crystal and used as an added sweetener. Berries and melons, such as cantaloupe, contain the highest amount of fructose among fruits. Cantaloupe contains roughly 4 grams of fructose per 100-gram serving, while blueberries contain around 5.5 grams of fructose per 100 grams.
Glucose is the most important simple sugar for your body as it is the primary source of energy for all organs and mechanisms, including brain activity. Your body can create glucose as it breaks down complex carbohydrates, and it is also present naturally in fruits. A 100-gram serving of banana has 5.6 grams of glucose, while apples and oranges have approximately 2 grams and 8.5 grams of glucose, respectively, for the same serving size. Glucose is less sweet than fructose.
Sucrose, also the name for table sugar, is a blend of glucose and fructose and is present in ripe fruits. Its highest sources include mangoes, bananas and nectarines. A 100-gram serving of bananas has 6.5 grams of sucrose, while mangoes have 9.9 grams per same-size serving. Nectarines have over 6 grams of sucrose per 100 grams.
Blood Sugar and Fruit
Because fruits are high in dietary fiber and fructose, they do not cause drastic changes in blood sugar levels. This makes many of them a low-glycemic-index food -- the glycemic index being a measurement of how much carbohydrates affect blood sugar levels. However, sweeter fruits, such as melons, and dried fruits, which have a higher sugar content per serving size, are considered medium- glycemic-index foods as they may affect blood sugar levels more, increasing the chances of spikes. The American Heart Association states that foods high in natural sugars, such as fruits, are better for you than those containing added sugars, as foods with natural sugars also contain essential nutrients, while added sugars only provide "empty" calories.