I know the body always fights to get back to its "natural" weight and size. Are there any studies out there (i can't find) that prove after a cycle and gaining more muscle your body doesn't fight against itself ?

Example:
Say a persons natural body weight is 160 which they have a perfect base and naturally cannot go any further. They cycle gain to 175 solid. Now after PCT the strength is never what it was as while you are on. So after PCT you are still eating good but does your body try and fight to remove that extra 15 lbs ?

Is it now a fight between you and your body ?

Look for some scientific prove not opinions.