My theory/opinion is that the chubbier you get, the less competitive it becomes for her. Despite women appreciating a hard bod, they aren\'t as \"visually-demanding\" as males are and can overlook flaws in physique if they can get just about everything else. She sees you as a catch and is content with your extra pounds because if you were in the absolute prime, she knows she\'d have a much greater threat from outside forces (i.e. other women) to her relationship with you. It\'s in her head, despite your reasons for wanting to get fit again. I would NOT call her out on said-theory, and to some extent it\'s not even all that surprising.
At least that\'s what I suspect from the outside looking in.