Hi cris I have. Question please help me. I'm on day 17 of my fast 5-3 started with 130 ib and now in 110. I have been feeling hungry for the past few days to the point that I wanted to cry at night of being hungry ... I can't go to sleep because of hunger feeling... I don't want to quit but I don't know if this is mental or true hunger because I read even skinny people can go 21 days... I feel extremely cold too.. In the morning I don't feel too hungry but by 12 it comes to me and doesn't go away until I sleep... Any help appreciated