Too much of anything is bad. The human body is designed for a variety of foods and food groups. 100 percent fruit juice is much better than soft drinks or drinks made with less than 100 percent juice (those make up the difference with water, sugars, and sometimes flavorings).ne to two eight ounces servings of 100 percent fruit juice per day won't be bad but more than that may be more calories than you need and your vitamin needs will have been met or exceeded, the rest just passes through your system unused.