I was out for several months with a leg injury and therefore, was not able to hit the gym. Surprisingly i lost 4 lbs during those weeks (6). I'm now back in the gym and have started running and ifting some weights. However, i have gained weight which i think is very unusual considering i am working out 3-4 times a week rather than sitting on my butt the whole time. Does anyone ahve an explanation as to why this happened? thanks

It is highly likely that the weight you lost was actually muscle mass, and now that you are back in the gym, you are starting to build it back up again, which will add weight. My husband was in the hospital for 2 weeks after an accident, and then unable to do any physical activity for 3 months after that. He lost about 25 pounds, mostly all muscle mass, and once he was able to get active again, he gained that back and more. I would consider it normal. Just get back into a good routine, and things should balance out again before long.