I realize this thread is a few days old, and I hope your guy is still doing alright. I just wanted to echo mlededee on the Pangea diet with insects. I also feed it year-round to various aged geckos and have had great results with both weight gain and maintaining healthy weights. I also don't think the small fluctuations you're seeing are anything to be concerned about, and while I don't weigh my adults hardly at all, I do notice them packing on a little size during the fall and slimming out as the winter months go by.