The 90 Day Challenge is an exciting contest created by the creators of Body by Vi dieting system. This diet plan utilizes meal replacement shakes to enhance a person’s weight loss. Each of the meal replacement shakes taste like cake and are high in protein and low in both calories and fat. Followers of this plan are supposed to replace two of their meals per day with these shakes in order to see the best results. To motivate its users, the creators of the plan developed the 90 Day Challenge. This challenge is a contest that is open to any new user of the diet plan. It takes place during the first ninety days of your diet, and winners are chosen based on who lost the most weight and the most inches.