Coming inside should help. The weather is a factor no doubt. I use a lot of cooked brown rice in the colder months. It serves as a filler. If everything else with the dog is fine, he is healthy the called weight could be wrong. We had one once that was an active chain dog. Anything he heard, whereas other dogs would bark, he would run. I mean a 10ft. chain stiff as a board and just about an all out sprint. His spot looked like a jenny track. He was near peak condition all the time and his chain weight was his called weight. In this case, not knowing all the variable or specifics, I would guess if all is well with the dog, the called weight is not correct. Best of luck. EWO