To be sure you will lose weight fast and at least 5 pounds in a week, a low calorie diet is really a must. You won’t be able to lose weight fast if you want to eat foods that make you fat, like sugar based foods.
If you want to watch this video on youtube go here... https://www.youtube.com/watch?v=GCj9oHFfDQo
As I said before the diet is essential! And if you take most of the calories you consume throughout the day from vegetables and proteins, you will definitely drop and reduce your weight.
The problem is that most people don’t know what to do, how to exercise, so the video in this link https://www.youtube.com/watch?v=492m4LARJtc  will guide you throughout what you must eat and how to exercise for massive and fast weight loss.