Yep, 25 lbs. It's not unheard of. You can do google searches to read up on some other peoples' experiences, but presumably you won't believe them either. You could read 4 Hour Body, which has pics, but I guess you won't believe that either. I don't know what to tell you, but it happened. You could ask anyone at the SEM firm I work at, many of whom I convinced to do CrossFit with me, what changes in my physique were readily apparent.
An interesting side-effect from the experience is that I finally diagnosed my angioedema without major urticaria that I'd been having since I was twelve, off-and-on. I'd always had swelling of the face or fingers or tongue or throat, periodically, that would occur in the morning. It went away for some years, but came back a couple years ago. It wasn't coincident with any particular food or activity so it was hard to see how it could be a food allergy. I would take Zyrtec once a day to manage it. However, after going on GOMAD, I couldn't manage it anymore, it was getting to dangerous levels. I went to an immunologist who didn't know what was happening either. After extensive research, I discovered that some people are sensitive to the casein protein found in the milk from common breeds of cattle in the US. It breaks down into an opioid in the body, and some of us produce a histamine response from it. I thank the a2milk company of Australia for providing the resources to help me figure it out. I've since been able to keep the acquired muscle by taking pure whey protein with water.
Anyway, so unless you think I just made up that food intolerance anecdote, yeah, it happened.