Is there cholesterol or fiber in the powder?

Works very well if you follow the instructions. I lost 50 pounds in 3 months.

How many days does one can last?

When I use this product, I consume nothing but this product and drinking water, which is not recommended by the manufacturer. For me, three cans lasts a little over 14 days and I lose around 15 lbs., net. I have no idea how long one can would last if used as directed. Hope this helps

Will you gain the lost weight back , if you stop using this product?

If you follow the program as laid out in their brochure and stick to good eating habits you shouldn’t. I had really good luck with this plan and kept the weight off for over 5 years. I have gained weight back now due to returning to really bad habits. If I had stuck to good habits I would still be good. But you can’t eat candy, chips and drink 4 or 5 cokes a day and expect to stay slim. My weight gain is entirely my fault.