40 days is a short period of time and most think that it is not possible to really make a difference. However I will tell you that is incorrect. It is first and foremost all about diet. In fact 90% is diet the rest is exercise. You need to reduce your sugar, thus carbohydrate intake dramatically. As we all know this will force your body to use fat for fuel rather then what you are eating. Now this surely does not mean you can eat anything you want. Calorie intake still needs to be monitored and should be in the ballpark of 800-1200 calories depending upon your size. Stay consistent is the trick. it is a life style not a quick fix. 40 days goes by fast, but you can see tremendous results if you stick with it.