I understand what you mean. My Mom was really scared when I told her I wasn't going to eat any solid food for 11 days when I first started cleansing. She thought for sure I would get violently ill or pass out and be rushed to the hospital. (smile)
Of course that didn't happen and I am on my 4th Master Cleanse now. I normally tell people I am cleansing for physical AND spiritual reasons and tell them if they do not have any positive input, keep their comments to themselves. I normally try not to tell very many of my co-workers that I am fasting because they have too many questions and negative comments. I will tell my close friends and family members and offer to let them read the book if they still have doubts. So, do what you feel comfortable with. I find I have much better results if I don't have people in my face going "are you sure you don't need to eat something?"