Linda,

I quit smoking a year ago this month.
Had been smoking for about 14 years (started young)

If you go to webmd.com you will find that most of the doctors there advise against fasting for weight loss or cleansing reasons (they can't disputeit for religious reasons)
When I say fasting I mean NO food (just water) for 2 days or more. That is what most people think of as a fast - especially impressionable youngsters.

2 points:
1) Religious fasting is not always NO food, most allow food at certain times fo the day, like you said.
2) Your cleanse involved a nutritional formula which, I would say, makes it not a fast but rather just a cleanse which is much better.

I used to do a 2 day fast once a month when I first started my weight loss journey and at first I felt great but after 2 months my body started reacting really badly to it. That's when I went to webmd.com and found out why.