I Would Like An Exact Answer

Can SI please tell me what causing player weight gain and loss?

There is unlikely to be an official answer but it is possible that weight will go up during the close season with no training, due to injury or lack of games- weight should go down during the season if the player is training hard and playing regularly, Weight may also go up with age if the player starts the game as a youngster.

Yury- I have edited your thread title to be a little less demanding