If you've made juice, you know that it takes a lot of fruit to make a container of juice. Even if juice contains pulp, it usually doesn't contain all of these fibrous parts. Juice is not a low calorie drink. We don't feel as filled up from juice because it doesn't contain any fiber. For many people, drinking a caloric beverage, such as juice, isn't as satisfying as eating the same amount of calories in food.
Fresh juice is certainly tasty and an excellent source of many nutrients.
Less stable vitamins, such as vitamin C, are not compromised in fresh juice as they may be in some processed varieties. Otherwise, moderation is the key.