Apple Juice as well as Orange juice, like the juice of most citrus fruits, are quite acidic, so too much acidic liquid in the body can upset the stomach.
Despite having some a-ma-zing health benefits, apple juice is high in sugar. That’s why I never drink more than a glass of apple juice per week. I know, I know it’s insanely tasty, I’m lovin’ it too, but I love the idea of getting a ballerina-body even more.
Since oranges do have a relatively high glycemic load and apple juice is high in sugar, drinking a lot at once can cause massive fluctuations in your blood sugar levels, which can lead to varying energy levels throughout the day, and can lead to complications for diabetic or pre-diabetic patients.
So if you want the complete benefit of oranges or apples, avoid orange or apple juice and eat the orange or the apple itself. That is the only way to get a good amount of fiber to boost your digestion; orange juice has almost no fiber.