Once again, you need to start working on his bite control, something he sorely missing by leaving his littermates so young. We have all tried to explain our methods to you, but apparently you are not reading them.
Please go back to your earlier posts and re-read the parts that explain how to contol puppy biting.
To repeat the basics...if you run and he is allowed to chase, he WILL become over excited and nip and bite at your legs. You need to stop moving so that he learns to stop chasing and/or remove yourself completely if he becomes too excited by either leaving the area yourself or putting him in his crate for a few minutes until he settles down.
BUT, playing chase games with a 3 month old GSD IS going to result in his biting you and chasing you. He needs to learn bite inhibition before any chase/running play is allowed.
On his weight issue, have you had him tested for pancreatic insufficency yet? That is common in young male GSDs and prevents proper digestion of fats & protei

Toto, CD, RN, CGC answered on 2/8/12. Helpful? / 0