I have taken part in anthropological classes on Muslim societies and religious traditions for a couple of years now, and have gotten interested in the practice of fasting. I want to take part in Ramadan next week, but I have a several questions. First, I am wondering how it is for people who are underweight, or quite thin, to fast all day. I am a bit worried that it will do more harm than good to not eat for so long. The spiritual aspect of the practise is calling me though, and that is why I am asking your advice. Secondly, how do people not feel isolated when their family and general society around them is not taking part in the same practice? 

I am looking forward to reading the answers!