Why is fruit juice not a substitute for whole fruit?

According to the USDA MyPlate guidelines, 100% fruit juice can be counted as a serving of fruit. However, it’s not recommended to get all of your fruit servings from fruit juice. While it might provide a more concentrated source of some nutrients such as vitamin C, fruit juice pales in comparison to whole fruit for fiber content and satiety. Fruit juice is also a very concentrated source of calories so drink it in moderation.