i too am grossly underweight and i think it's because my body doesn't get enough nutrients probably due to leaky gut. i'm in the middle of a terrible die off reaction that started 2 days ago. i'm sure the H2O2 (Hydrogen-Peroxid) is killing candida and some other bugs. i developed a pretty bad asthma attack and i'm really fatigued. candida strands are coming out in my stool. it's hard but i'm going to stay the course and detoxify as fast as i can. hopefully these symptoms clear up soon. i don't mind the die off so much because i know i have to pull through it to get better and most importantly that big changes are happening in my body. i could easily alleviate my symptoms by consuming lots of Sugar and feeding the candida, but i won't...it has to die!!!! lol.