My one male weighed around 600 Grams last winter and went off feed for several months. Once he went back on, he was pounding small rats and this winter is a whopping 1300 grams. Needless to say he's skipped his last 3 meals so another fast is probably in store. I also have two females that have each been off feed since late October. Neither is of breeding weight. I've just given into the fact that BPs will go off feed and there is little to do but wait it out.